EP2931109B1 - Dishwasher for operation in various voltage systems - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a designed for commercial use dishwasher, in particular a (basket) feed-through dishwasher, which can be operated in different low-voltage networks. Furthermore, the invention relates to a method for energy saving in the standby mode of a dishwasher.

TECHNICAL BACKGROUND OF THE INVENTION

Dishwashers designed for commercial use, hereinafter also commercial dishwashers, are characterized, without restriction of generality, by the fact that they are structurally designed for an almost continuous operation, which places particularly high demands on pumps and power-electric components such as relays and contactors, the millions of cycles should work without failure.

In addition, commercial dishwashers should clean the dishes as quickly and hygienically as possible while consuming as little water and energy as possible. Therefore, a rinse cycle (rinse) of a commercial dishwasher usually lasts only very short (typically only a few minutes) and requires only small amounts of fresh water (typically only a few liters). The water used for rinsing the items to be washed is electrically heated in a rinsing water tank and in a boiler of the dishwasher by means of radiators. Tubular heaters are often used.

berechnet werden, wobei U die elektrische Netzspannung des Niederspannungsnetzes, an das die Spülmaschine angeschlossen ist und R den Widerstand des Rohrheizkörpers bezeichnet. Mit der Formel $I=\frac{U}{R}$

lässt sich der Strom I durch den Rohrheizkörper berechnen, der entsprechend abgesichert werden muss. Die vom Rohrheizkörper abgegebene Leistung ändert sich quadratisch und der Strom linear mit der Spannung, wenn der Widerstand des Heizkörpers konstant bleibt.Since the tubular heater can be considered in principle as a resistor R, which converts electrical energy into heat, the power P of the Rohrheizköpers simply as $\mathrm{P}=\frac{U^2}{\mathrm{R}}$

where U is the electrical mains voltage of the low-voltage network to which the dishwasher is connected and R denotes the resistance of the tubular heater. With the formula $I=\frac{U}{R}$

can the current I calculated by the tubular heater, which must be hedged accordingly. The power delivered by the tubular heater changes quadratically and the current linearly with the voltage, if the resistance of the radiator remains constant.

The following exemplary table, which does not claim to be exhaustive, makes it clear that there are many different grid voltages and safeguards for on-site grid connections worldwide: <b> Table 1 </ b> country 3-phase AC outer conductor voltage 1-phase AC voltage Typical protection Germany 400V 230V 16A, 25A, 32A Switzerland 400V 230V 10A, 16A Great Britain 415 V 240V 13A, 16A, 20A, 32A, 64A Industrial networks Europe 230V ./. 32A, 50A, 64A Australia 415 V 240V 15A, 20A, 32A Japan 200V 200V 20A, 30A Nets on ships 440V ./. 20 A Philippines 380V 220V 16A, 32A

In addition, the three-phase low-voltage networks are designed as a delta network (three phases without neutral) or star network (three phases with neutral), depending on the country.

In order to ensure that the dishwasher can be operated on the respective low-voltage network and despite various network connections optimum flushing performance is conventionally installed for different networks different on network type, mains voltage and protection adapted radiators and pumps in the dishwasher, often also several radiators in the Dishwasher can be combined. The various radiators and pumps in combinations with different types of network, mains voltages and fuses each lead to a different structure of the entire interconnection of the power electronics.

From this high variance in the radiators and pumps and their combinations and the various power electrical circuits for the individual low-voltage networks follows a high variance of the dishwasher. The storage of radiators and other power electronic components is extensive, the ordering and spare parts of the machinery complicated and thus error-prone and the maintenance of the dishwasher accordingly consuming.

Commercial dishwashers usually consume only a small amount of water per rinse cycle, but they often have high energy consumption, especially in standby mode. Without limiting the generality, it can be assumed that approximately 15 to 45 liters of water are kept in the rinsing water tank of a commercial through-basket dishwasher and 2.0 1 to 5.0 liters of fresh water are heated in the boiler per rinsing cycle. To clean the items to be washed, the tank water is circulated. At the end of the rinse cycle, the dishes are washed away with hot fresh water from the boiler. The low water consumption is achieved by the fact that the tank water is used to clean the dishes for the most part again and again. The regeneration of the tank water takes place via the fresh water which is supplied from the boiler at the end of a rinsing cycle. Due to the very short flushing times, the fresh water in the boiler must be heated from tap water temperature (about 5 ° C-25 ° C) to about 80-85 ° C in a very short time (e.g., less than 2 minutes). The heating of the water in the boiler is carried out electrically via one or more radiators with a capacity of up to 12 kW. The flushing water tank is heated parallel to the boiler to keep the temperature of the dishwasher at about 62 ° C. In particular, the rinsing of cold dishes of the tank are withdrawn considerable amounts of energy. In a feed-through dishwasher for commercial use, the performance of the tank heater is typically up to 5 kW.

Conventionally, the water temperature in the boiler and Spülwassertank kept as constant as possible at the desired temperatures, which requires that the heaters of the boiler and the Spülwassertanks also during times in which no rinsing cycle is active (standby mode), energized and accordingly increase the energy consumption of the dishwasher.

US 4,561,904 discloses a system and method for controlling a feed-through dishwasher, which consists of a series of workstations and the wash wipes, washes, dries, etc. A sensor at the entrance of the first workstation detects the items to be washed on the conveyor belt of the dishwasher and the forward movement of the conveyor belt also monitored to guide the dishes through the dishwasher.

WO 2006/034760 A1 relates to the energy-saving operation of dishwashers and proposes a method and an apparatus in which a group of electrical consuming elements of a dishwasher is assigned a maximum total electrical power. Furthermore, each electrical load element of this group is assigned at least two power levels. In a demand determination step then becomes depending on an operating state B of the dishwasher selected an optimal combination of power levels, wherein for each consumer element, the selected power level is adapted to the power consumption of the consumer element in the operating state B and wherein the total power of all consumer elements does not exceed the maximum total electrical power. Furthermore, the operation of the dishwasher can be divided into three phases, a start phase, a switch-on phase and a load control phase.

SUMMARY OF THE INVENTION

An object of the invention is to improve a dishwasher so that it can be operated as possible without adaptation in different low-voltage networks. Another object of the invention is to provide a dishwasher that can be operated energy-saving. It is further desirable that even with an energy-saving operation of the dishwasher, the dishwasher can perform a cleaning cycle in the shortest possible time and allows hygienic cleaning of the dishes.

The invention discloses a (commercial) dishwasher, which independently recognizes the on-site low-voltage network to which it is connected and optimally distributes the available power of the on-site low-voltage network (optionally taking into account a safety reserve) to individual electrical load elements of the dishwasher based on the recognized low-voltage network , For this purpose, a power controller can be provided in the dishwasher, which controls the distribution of power from the low-voltage network. For example, the power controller may include a switching unit which, depending on the detected low-voltage network, interconnects the individual phases of the low-voltage network with the electrical consuming elements. In addition, the consumer elements can be switched on and off dynamically, for example as a function of the electrical consuming elements of the dishwasher required in the respective process step of the rinsing cycle.

In one embodiment of the invention, the (commercial) dishwasher may optionally enable energy saving operation. According to this embodiment, the dishwasher monitors in standby mode the water temperatures in a tank or boiler of the dishwasher and ensures that a
certain lowest possible temperature is not exceeded. This temperature is chosen so that in the event of start of a rinse cycle (ie rinse operation is initiated and sweep cycle), the water in a rinse cycle of desired (target) temperature, at the desired time and optionally (depending on the embodiment) as well can be provided in the desired amount to allow a hygienic rinsing operation. For example, it is thus possible to monitor the fresh water temperature for rinsing the ware in the boiler and / or the rinse water temperature in the tank of the dishwasher. According to the measured temperature, the dishwasher activates and deactivates the heating of the boiler and / or tank.

Compared to conventional dishwashers, which keep the water temperature in the boiler and / or tank always at the desired target temperatures even in standby mode, the water temperatures in standby mode are reduced to minimum temperatures. Thus, the power consumption of the dishwasher in standby can be significantly reduced while ensuring a hygienic cleaning of the dishes.

According to an exemplary embodiment of the invention, a dishwasher, in particular a feed-through dishwasher, for operation in different

Voltage networks proposed comprising a plurality of electrical load elements, a power controller, and a power input terminal with a plurality of conductors for connecting the power controller with the conductors of the on-site low-voltage network, with one or more phases, in particular three phases. The power controller is able to detect the type of low-voltage network on the basis of the power controller supplied single-phase or multi-phase grid voltage of the low-voltage network. Further, the power controller comprises a switching unit which electrically connects the conductors of the power input terminal to groups of the load elements depending on the detected type of low voltage network. Each group comprises at least one consumer element or a plurality of consumer elements connected in parallel to each other, and at least one switch for controlling the power supply to the consumer elements of the respective group.

In exemplary embodiments, the switching unit may be single-stage, two-stage or multi-stage.

In a further exemplary embodiment, a separate switch is provided for each electrical load element of each group. Furthermore, the power controller can be designed as a power electronic printed circuit board (PCB). It is also possible that the power inlet clamp of the dishwasher forms part of the power controller. The mains input terminal and / or the terminals of all consumer elements of the dishwasher can be designed, for example, as a releasable connecting element, in particular as a plug.

In a further embodiment of the invention, the dishwasher for detecting the voltage network comprises a measuring unit for determining the number of phases of the voltage network; and a processor unit for detecting the type of voltage network based on the determined number of phases.

The measuring unit may, for example, be designed so that it determines the relative (phase) position of the phases and / or the mains voltage of the low-voltage network. The processor unit may for example be adapted to recognize the type of voltage network based on the determined number of phases, and on the basis of the relative phase position and / or the mains voltage. Among other things, which parameters are required to detect the type of low-voltage network also depends on the low-voltage networks in which the dishwasher is to be used and what differences exist between these low-voltage networks in terms of voltage, number of phases and relative phase.

In a further exemplary embodiment, the processor unit is capable of switching the switches of the switching unit and of the groups of electrical load elements such that the total current supplied to the electrical consuming elements does not exceed the protection of the low-voltage network, optionally taking into account a safety reserve. In this case, the power supply to each consumer element in at least one of the groups of electrical consumer elements can be controlled individually with a switch by the processor unit.

Furthermore, it is possible for the processor unit to switch the power supply to the electrical consuming elements as a function of the respective process step of a rinsing cycle of the dishwasher by means of the switches of the groups of electrical consumer elements.

According to a further exemplary embodiment of the invention, the processor unit of the dishwasher is adapted to read out the security of the low-voltage network from a memory of the line adjuster or the dishwasher or a coding circuit manually coded according to the protection.

In another exemplary embodiment, the power controller includes a memory that stores configuration information. This configuration information may indicate, for example, how the processor unit, depending on the detected (type) low-voltage network and its protection must cause the controller unit to switch the switches of the switching unit and the individual groups of electrical load elements, so that the power of the low-voltage network to the electrical Consumers of the dishwasher is distributed, that the total current does not exceed the protection of the low voltage network, optionally taking into account a safety reserve.

In addition, the resistance values of the individual electrical load elements of the dishwasher can also be stored in the configuration information of the memory. Furthermore, it is possible that the processor unit reads out the configuration information for the respective recognized low-voltage network and its protection from the memory and switches the switches of the switching unit on the basis of the read-out configuration information. The processor unit can optionally control the voltage of the Low voltage network from a memory of the line actuator or the dishwasher read, for example, if this can be entered by the user or must.

According to a further exemplary embodiment of the invention, the switching unit is capable of switchably connecting each phase of the mains voltage to a group of electrical load elements. In reality, this interconnection may look as follows: If the detected low-voltage network is only a single-phase network, all the consumer elements are driven with this one phase. In a three-phase delta network, the three phases are connected to a respective group (or groups) of electrical load elements. In a three-phase, neutral-mode, low-voltage network, the three phases and the neutral are respectively connected to a respective group (or groups) of electrical consuming elements.

In order to enable a connection corresponding to the number of phases (and optionally also voltage) of the recognized (type of) low-voltage network, the power controller may, for example, have switches to connect each phase of the mains voltage to a group of electrical load elements. The switches can also be designed as a short-circuit switch or bridges to short circuit the head of the power input terminal of the dishwasher according to the detected low-voltage network and so supply the individual phases by means of the individual (possibly with each other short-circuited) conductors to the consumer elements. In one embodiment of the invention, the processor unit is capable of switching these switches, depending on the type of low-voltage network detected, to short-circuit individual conductors of the mains input terminal and / or to connect them to the groups of consumable elements.

The switches do not necessarily have to be provided in the dishwasher as part of the power controller, but corresponding switches or bridges may alternatively be operated manually, e.g. during the installation of the dishwasher, switched according to the existing low-voltage network, or set.

In another exemplary embodiment of the invention, the power controller for the load elements comprises a plurality of power regulators. These can be designed, for example, as pulse width modulators. The power regulators serve to reduce the (electrical) power to be delivered to the consumer elements. Everyone Power controller leads the reduced power in each case to an electrical load element (or optionally also several).

In a further embodiment, the dishwasher may also comprise a control unit which communicates via a data bus with the processor unit of the power controller. The processor unit receives control signals for the electrical consuming elements of the dishwasher from the control unit and, in accordance with the control signals, controls the supply of power to the respective consumer elements. In another implementation, the functionality of the control unit may also be implemented in the processor unit of the power controller itself. If the power controller and the control unit are executed on different electronic printed circuit boards (PCBs), it is advantageous to provide corresponding plug connections on the electronic printed circuit boards in order to be able to couple them by means of a data cable and thus enable the communication between the control unit and processor unit (power controller).

Another embodiment of the invention relates to a feed-through dishwasher comprising a boiler with a boiler heater for heating fresh water and a temperature sensor for determining the temperature of the fresh water in the boiler. The boiler provides fresh water for rinsing the dishes in a rinse cycle. The feed-through dishwasher further has a power controller for detecting the low-voltage network to which the feed-through dishwasher is connected, and a temperature control unit for continuously monitoring the fresh water temperature in the boiler by means of the temperature sensor while the feed-through dishwasher is in a standby mode. The temperature control unit further controls the power supply to the boiler heater in the standby mode of the feed-through dishwasher, so that the water temperature in the boiler does not fall below a respective predetermined minimum boiler temperature. The respective predetermined minimum boiler temperature is calculated as a function of the performance of the detected low-voltage network so that the fresh water is provided for rinsing in the desired amount, with desired temperature and at the desired time in the rinse cycle from the boiler in a rinsing cycle to a to allow hygienic rinsing operation.

In one embodiment of the invention, the temperature control unit corresponds for example to the control unit or the processor unit of the power controller of the dishwasher previously described.

In a further embodiment of the invention, the feed-through dishwasher also includes a rinse water tank with a tank heater for heating the rinse water and a temperature sensor for detecting the temperature of the rinse water in the rinse water tank, and a circulation pump for circulating the rinse water in the rinse water tank during the rinse cycle to the Clean dishes. Further, in the standby mode of the feedthrough dishwasher, the temperature control unit continuously monitors the purge water temperature in the purge water tank by means of the temperature sensor, and controls the supply of power to the tank heater in the standby mode of the feedthrough dishwasher so that the purge water temperature in the purge water tank becomes a predetermined minimum Tank temperature does not fall below, with the predetermined minimum tank temperature depends on the performance of the detected low-voltage network.

Optionally, the respective predetermined minimum tank temperature depending on the performance of the detected low-voltage network can be selected so that the rinse water is provided in the rinse cycle with the desired temperature and at the desired time from the water tank.

In one embodiment, the temperature control unit may, for example, prioritize the boiler heater in the power supply to the tank heater to ensure that in a rinse cycle the fresh water for rinsing in the desired amount, at the desired temperature and at the desired time in the rinse cycle from the boiler to Is made available, so that a hygienic flushing operation is ensured. In such a case, it may happen that not enough "residual power" is available in order not to drop the rinse water temperature below the specified tank temperature. Alternatively, it is of course also possible to prioritize the tank heater in the power supply to the boiler heater to ensure that in a rinse cycle, the rinse water of Spülwassertanks with desired temperature and at the desired time in the rinse cycle is provided for rinsing the dishes to ensure a hygienic flushing operation.

The respective predetermined minimum temperature of the boiler or the water tank can be dependent on various factors / parameters. For example, the respective predetermined minimum temperature of the boiler or of the water tank may (additionally) depend on at least one of the following parameters:
the maximum power that can be supplied to the boiler heater or the tank heater from the recognized low-voltage network, the respective amounts of water from the boiler or water tank required in a rinsing cycle, the desired temperatures of the respective amounts of water from the boiler, or the water tank, which are required in the rinsing cycle, and the time in the rinsing cycle to which the respective amounts of water from the boiler, or water tank are to be available with the respective desired temperatures.

By lowering the standby temperatures in the tank and / or boiler of the dishwasher according to the method described above energy is saved because tank and boiler must not be permanently heated to the target temperatures. As a result, thermal radiation losses are minimized in the environment of the dishwasher.

Another embodiment of the invention relates to a method for energy saving in a feed-through dishwasher. According to this method, the low-voltage network to which the feed-through dishwasher is connected is detected and the fresh-water temperature in a boiler of the dishwasher is continuously monitored while the feed-through dishwasher is in a standby mode. The boiler is equipped with a boiler heater for heating fresh water. According to the method, the power supply to the boiler heater is controlled in the standby mode of the feed-through dishwasher so that the fresh water temperature in the boiler does not fall below a respective predetermined minimum boiler temperature. The respective predetermined minimum boiler temperature is selected as a function of the performance of the detected low-voltage network so that the fresh water is provided in a desired rinse cycle, desired temperature and at the desired time in the rinse cycle from the boiler to a hygienic rinsing operation to enable.

The method may further comprise continuously monitoring the purge water temperature in a purge water tank of the feed-through dishwasher in a further embodiment, further assuming that the purge water tank comprises a tank heater for heating the purge water. The power supply to the tank heater is controlled in the standby mode of the feed-through dishwasher so that the rinse water temperature in the rinse water tank does not fall below a respective predetermined minimum tank temperature, wherein the predetermined minimum tank temperature depends on the performance of the detected low-voltage network.

As already shown, optionally the respective predetermined minimum tank temperature depending on the performance of the detected low-voltage network can be selected so that the rinse water is provided in the rinse cycle at the desired temperature and at the desired time from the water tank.

According to the method, according to further embodiments, it is possible to prioritize the boiler heater in the power supply to the tank heater to ensure that in a rinse cycle, the fresh water for rinsing in the desired amount, with the desired temperature and at the desired time in the rinse cycle of Boiler is provided so that a hygienic flushing operation is ensured. Alternatively, however, the tank heater can be prioritized in the power supply to the boiler heater to ensure that in a rinse cycle the rinse water of the rinse water tank with the desired temperature and at the desired time in the rinse cycle from the rinse water tank is provided for rinsing the dishes, so that a hygienic flushing operation is ensured.

Another embodiment of the invention is a computer-readable medium storing instructions that, when executed by a processor unit of a feed-through dishwasher, cause the feed-through dishwasher to perform the steps of the energy-saving method in a feed-through dishwasher according to any one of the various described embodiments.

DESCRIPTION OF THE FIGURES

Fig. 1

zeigt eine gewerbliche Durchschubspülmaschine gemäß einer beispielhaften Ausführungsform der Erfindung,

Fig. 2

zeigt einen funktionserläuternden Aufbau der Durchschubspülmaschine nach Fig. 1,

Fig. 3

zeigt einen Leistungsteller gemäß einer Ausführungsform der Erfindung, der die Zuführung der Leistung aus dem Niederspannungsnetzes an eine Boilerheizung, eine Tankheizung und die Umwälzpumpe einer Spülmaschine steuert,

Fig. 4

zeigt eine beispielhafte Verschaltung der einzelnen elektrischen Verbraucherelemente in Fig. 3 in einem Sternnetz,

Fig. 5

zeigt eine beispielhafte Verschaltung der einzelnen elektrischen Verbraucherelemente in Fig. 3 in einem Wechselstromnetz, und

Fig. 6

zeigt die beispielhafte Verschaltung der einzelnen elektrischen Verbraucherelemente in Fig. 3 in einem Dreiecksnetz.

The invention will be described in more detail by means of embodiments with reference to the figures. Corresponding elements and details in the figures are provided with the same reference numerals.

Fig. 1

shows a commercial feed-through dishwasher according to an exemplary embodiment of the invention,

Fig. 2

shows a functionally explanatory structure of the feed-through dishwasher Fig. 1 .

Fig. 3

shows a power controller according to an embodiment of the invention, which controls the supply of power from the low-voltage network to a boiler heater, a tank heater and the circulation pump of a dishwasher,

Fig. 4

shows an exemplary interconnection of the individual electrical load elements in Fig. 3 in a star net,

Fig. 5

shows an exemplary interconnection of the individual electrical load elements in Fig. 3 in an AC network, and

Fig. 6

shows the exemplary interconnection of the individual electrical load elements in Fig. 3 in a triangle net.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the invention relates to the design of a dishwasher, in particular for commercial use, which can be operated in different low-voltage networks. Advantageously, the dishwasher is designed so that, despite the ability to operate the dishwasher in different low-voltage networks, ideally no differences in the structure of the dishwasher, especially with regard to the (number of) installed radiators, pumps and power electronic components such the power controller, needs.

The dishwasher according to this aspect of the invention is able to independently recognize the on-site low-voltage network to which it is connected and optimally based on the detected low-voltage network, the available capacity of the on-site low-voltage network (optionally taking into account a safety reserve) to individual electrical consumer elements to distribute the dishwasher. It is thus possible, depending on the detected low-voltage network, to use its maximum power effectively. To ensure this distribution of power supplied by the on-site low-voltage grid, the dishwasher includes a power controller that controls the distribution of power from the low-voltage grid. The power controller can for this purpose comprise a switching unit which, depending on the detected low-voltage network, interconnects the individual phases of the low-voltage network with the electrical consumer elements. The switching unit can, as will be explained in more detail below, be formed in one or more stages.

The electrical consumer elements, which are taken into account according to the invention, are not necessarily all electrical consumer elements of the dishwasher, but for example, only those that can absorb significant power. For example, these are electrical load elements that have a current flow in the three-digit mA range or cause more, such as circulating pump or radiator, or their heating coils for boiler or Spülwassertank. Electrical consumer elements that consume little power, for example, in the two-digit mA range or less, need not be considered, but can be considered, for example, a lump sum (for example, by a power reserve). Electrical consumer elements, which are traversed by very little current, are for example solenoid valves for supplying the fresh water or pumps for the rinsing chemistry, the power consumption of the power controller itself or the control electronics, etc.

The power controller can be designed as a power electronic printed circuit board (PCB). In one embodiment, the semiconductor power controller is implemented on a power electronic board, i. it includes substantially power semiconductor devices such as power diodes, thyristors, triacs, power MOSFETs and / or IGTB devices capable of switching the necessary currents and voltages occurring in a low voltage network. Compared to the use of contactors, the use of power semiconductors in the power controller multiplies the number of switching cycles, which significantly improves the service life.

For recognizing the on-site low-voltage network to which the dishwasher is connected, the dishwasher according to one embodiment comprises a measuring unit and a processor unit. The measuring unit determines, for example, the number of phases of the on-site low-voltage network and optionally their (relative) phase relationship to one another and / or the voltage of the on-site low-voltage network. From the determined information of the on-site low-voltage network, the processor unit subsequently determines to which type of low-voltage network the dishwasher has been connected and configures the switching unit of the power controller such that the individual phases of the detected low-voltage network are supplied so that they can supply power to corresponding electrical consuming elements.

Optionally, the individual conductors of the mains connection can be additionally secured with a fuse. Furthermore, it is possible for individual information on the on-site low-voltage network to be configured manually, eg during the installation of the dishwasher. For example, the voltage of the low-voltage network and / or the on-site protection of the low-voltage network could also be configured manually. Depending on the low-voltage networks in which the dishwasher is to be operated, individual parameters of the low-voltage network can also be configured / specified become. The configuration information can be stored, for example, in a data memory of the power controller of the dishwasher, to which the processor unit can read and optionally also write access.

In one embodiment of the invention, the power supply to each electrical load element may be individually controlled with a switch by the processor unit. Each phase of the on-site low-voltage network is advantageously connected to a group consisting of several electrical consumer elements, but the individual consumer elements can be individually acted upon by means of the associated switch with power. In this case, it is also advantageously ensured that the total current supplied to the electrical consuming elements as a function of the respective process step of the rinsing cycle does not exceed the protection of the low-voltage network, optionally taking into account a safety reserve.

In an exemplary embodiment of the invention, the electrical consumer elements of a feed-through dishwasher according to the invention, which are supplied by the power controller with power from the on-site low-voltage network, the heating coils of the radiator for the flushing water tank and the boiler, and a circulating pump for circulating the rinse water in Spülwassertank. The circulation pump motor can also be controlled by a frequency converter. Optionally, further electrical consumer elements can be provided in the feed-through dishwasher, which can also be supplied with power by the power controller. These may be, for example, solenoid valves, dosing pumps for the rinsing chemistry, a pump for supplying the fresh water from the boiler and / or a pump for pumping out rinsing water. In general, these elements consume little power compared to the radiators of the boiler or the rinsing water tank and the circulation pump. It is therefore possible that these only slightly power-consuming elements of the dishwasher are already taken into account with a safety margin and thus need not be explicitly taken into account by the power controller in the distribution of power from the detected low-voltage network. Of course, it is also possible to consider consumer elements with low power consumption in the distribution of the connected load of the low-voltage network; This primarily only increases the complexity of the power distribution.

The invention is described in the following paragraphs primarily with respect to a dishwasher designed for commercial use, in particular a (rack) feed-through dishwasher. However, the principles of the invention are not intended to be limited to use in such a feed-through dishwasher. A feed-through dishwasher according to an exemplary embodiment of the invention is shown in FIG Fig. 1 shown. Fig. 2 shows a functionally explanatory structure of the feed-through dishwasher Fig. 1 , The exemplary through-feed dishwasher comprises in its upper region a washing compartment, which is formed on the one hand by the rear wall and the rinsing water tank of the feed-through dishwasher and on the other by the example of the top to be pivoted open hood of the feed-through dishwasher. The washing compartment serves to receive the items to be cleaned.

The items to be washed are cleaned by circulating the rinsing water in the rinsing water tank, which is located in the lower area of the rinsing room, as in Fig. 2 can be seen. The rinse water tank has a radiator for heating the rinse water and can typically accommodate a rinse water amount of about 15 to 45 liters. To clean the items to be washed, the dishwasher comprises a rotatable washing arm, which is rotatably arranged in the lower region of the washing compartment below the items to be cleaned. Additionally or alternatively, a rinsing arm can also be provided lying above the ware, as exemplified in FIG Fig. 2 shown. By means of the circulating pump, the rinsing water is pumped into the rinsing arm (or the rinsing arms) and cleans the dishes. Furthermore, the flushing arm can be used to rinse after the Umwälzphase in the rinse cycle with the items supplied from the boiler, heated clean water and so at the same time supply fresh water to the rinse water in the tank. Alternatively, a separate Nachspülarm be provided for this purpose. Corresponding pumps (motors) for supplying the rinsing water or fresh water via the rinsing arm (or Nachspülarm, if available), supply of the detergent and for removal of contaminated rinse water are also provided, but in Fig. 2 only hinted.

In a lower area of the feed-through dishwasher are the control electronics (control unit) of the feed-through dishwasher and the power controller, which will be discussed in more detail below, as well as the aforementioned circulation pump and the boiler. The capacity of the boiler, for example, correspond to the amount of fresh water required for rinsing. But it is also possible that the boiler holds more fresh water than necessary for rinsing. In this way, the Nachspülmenge to be adjusted to higher and lower values in accordance with the dishwasher. Not shown are other conventional elements of the feed-through dishwasher, such as the fresh water supply and rinse water drain, the heating of Spülwassertanks and the boiler, a frequency converter for controlling the pumps or mains connection of the on-site low-voltage network. The control unit and the power controller can be implemented on different electronic printed circuit boards (PCBs) and connected to each other via a data cable. But it is also possible to execute the control unit and the power controller in an electronic printed circuit board (PCB).

Without limiting the generality, it can be assumed by way of example that a flushing cycle of the feed-through dishwasher only takes a few minutes, e.g. 1, 2, 3, 4 or 5 minutes and only a few liters of fresh water are needed (e.g., 2 to 5 liters per rinse cycle). In one exemplary embodiment, the individual process steps of the rinsing cycle of the through-feed dishwasher include, for example, the so-called circulation time (circulation phase) in which the circulation pump of the dishwasher cleans the items to be washed by circulating the liquor in the rinse water tank, and a post-rinse phase in which the cleaned items to be washed Fresh water is rinsed. Between the recirculation time and the post-rinse phase, it is optionally possible to provide further phases, for example a drip break. Also, after the post-rinse phase, a further dripping pause and / or drying phase in which the ware is dried may also be provided before the rinse cycle ends. However, the invention is not limited by these exemplary operations in a rinse cycle.

In principle, the dishwasher according to the invention should enable hygienic cleaning of the items to be washed. This means that at least in one process step of the rinsing cycle, the water must have a temperature that ensures the hygienic cleaning of the dishes. If one starts from the exemplary rinsing cycle of a feed-through dishwasher described above, then either the final rinsing of the items to be washed with 2 to 5 liters of fresh water and / or the cleaning of the items to be wiped must take place by circulation at correspondingly high temperatures. For rinsing the fresh water should therefore have a temperature of 60 ° C to 90 ° C, advantageously from 80 ° C to 85 ° C. In an exemplary example, the fresh water is heated to 85 ° C for rinsing. If the rinsing process is to ensure the hygienic cleaning of the items to be washed, the items to be washed are cleaned for a certain time with rinse water in the temperature range between 55 ° C and 70 ° C, advantageously between 60 ° C and 65 ° C. In an exemplary example, in the circulation phase, rinsing the dishes with rinse water having a temperature of 62 ° C. In addition to the temperature, a hygienic rinse result can also be influenced by the duration of the rinse cycle and the final rinse, by the temperatures of the rinse water in the circulation phase and the fresh water in the final rinse phase, and by the rinse chemistry. For particularly long rinse times or when using special rinsing chemistry, the temperatures of rinse water and fresh water may differ from the typical temperatures listed above beispielhalft, in particular lower.

Without limiting the generality, it can be assumed by way of example that the electric radiators (or, where applicable, their individually controllable heating coils) of the boiler and the rinsing water tank, as well as the circulating pump represent the relevant power consumers in the dishwasher. These electrical load elements usually have a power consumption in the kW range, while other electrical consumers, such as electrically operated metering pumps and solenoid valves, the power controller, the control electronics, electrical controls or a display, etc. only require currents in the single-digit or double-digit mA range and thus contribute only slightly to energy consumption. Accordingly, in the following embodiments, priority is given to the electric radiator (or, where applicable, their individually controllable heating coils) of the boiler and the Spülwassertanks, as well as the circulation pump Durchschubspülmaschine, while the remaining electrical load elements are not considered separately in the power distribution by the power controller must be taken into account or taken into account by the inclusion of a flat-rate reserve in the distribution of the service by the service provider.

The heating of the water in the boiler or the rinse water tank is electrically via radiators. For example, can be used as a radiator, a tubular heater. In one embodiment, a heater has a plurality of heating coils (e.g., 2, 3, or 4) that may have different or identical heating cables. In an exemplary embodiment of the invention, a three-way radiator is used for boiler and / or flushing water tank covering the entire mains voltage range worldwide. In an alternative embodiment, the radiator for boiler and / or rinse water tank can also be designed as vier-helical.

A radiator may, for example, have a total heating power of up to 18 kW, but higher or lower heating capacities may also be used. The individual heating coils of the radiator can in an exemplary implementation individually controlled by the power controller. Each filament of the radiator can have a different resistance and thus gives off a different power at the same mains voltage. If the heating coils can be switched individually, this results in a large number of heating powers, which can be adjusted with the feeder. Depending on the available grid connection power at the customer and the operating state of the machine (standby mode or flushing mode, but also different phases in the flushing cycle), different heating strands can be switched on by the power controller. It also takes into account how the switching unit distributes the groups of consumable elements to the individual phases of the grid connection.

This makes it possible to install only a very small number of different radiators in the feed-through dishwashers, ideally only a single type of radiator, which significantly reduces the machine variants, i. up to 80% by network-independent worldwide (or at least in the desired destination countries) usability of the power electronics and the controlled radiators.

Furthermore, in one embodiment of the invention it is possible to connect the radiators by means of plugs (and possibly cables) to the power controller. The plugging of the radiator on the power controller means in comparison to the screw connection with the shooters a simplification and acceleration of the assembly processes.

Optionally, the power controller may also allow the electrical power to be distributed by half-wave control between boiler and flushing water tank, or between the boiler radiators. The heat output in the rinsing water tank and boiler can be adjusted very finely, which enables exact regulation of the temperatures in the rinsing water tank and boiler. Alternatively, the individual consumer elements can also be controlled with a pulse width modulation in order to control their power consumption.

The control unit of the feed-through dishwasher can transmit, for example, via a bus to the power controller, which heating coil is turned on and how the power is distributed between the individual heating coils (half-wave control). The software of the processor unit, for example, a microcontroller, the power controller takes over the control of the power semiconductors and ensures, for example, that they switch in voltage zero crossing and a switchover between different heating coils happens as possible flicker.

Fig. 3 shows a power controller according to an embodiment of the invention, which controls the supply of power from the low-voltage network to a boiler heater with four heating coils, a Spülbehälterheizung with a heating coil and to a circulation pump. The power to the circulation pump UP can optionally be interrupted with a safety relay 305, for example, to prevent the pump circulating the rinse water when the hood / door of the dishwasher is opened. The power controller 300 of the dishwasher has a power input terminal 301, which is designed as a connector and is connected to the on-site network. In the example shown, the mains input terminal 301 is designed as a 4-pole plug and accordingly four conductors are fed to the configuration switching unit 302. The conductors are labeled L1, L2, L3 and N, where N is the neutral and the conductors L1, L2, L3 are up to three phases of the low voltage network. But it is also possible to additionally provide a PE (Protective Earth) conductor and to carry out the mains input terminal 301 as a five-pin plug.

A measuring device 303 is in Fig. 3 connected in front of the configuration switching unit 302 to the conductors L1, L2, L3 and N. The measuring device 303 measures for each of the three conductors L1, L2, L3 whether a phase of the on-site low-voltage network is applied to it and, if so, the phase difference between the individual conductors. Furthermore, the measuring device 303 can also detect the voltage applied to the respective conductors L1, L2, L3. Based on these metrics, the processor unit 307 can determine which type of low voltage network has been connected to the power input terminal. The processor unit 307 can thus distinguish single-phase and three-phase low-voltage networks, recognize the voltage of the low-voltage network and recognize from the phase differences, whether it is a three-phase star network (with neutral) or a triangular network (without neutral).

When installing the dishwasher in a single-phase low-voltage network, one phase of the mains connection 301 may be connected to only one of the conductors L1, L2, L3 (eg, conductor L1). In this case, the measuring device 303 recognizes the single-phase on-site low-voltage network because only one of the conductors (eg L1) has an alternating voltage. When the processor unit 307 recognizes a single-phase low-voltage network based on the measurement results of the measuring device 303, it causes the configuration switching unit 302 to connect all groups of consumable elements to the one phase.

If the dishwasher is connected to a three-phase low-voltage network, it can be a star network (L1, L2, L3 and N connected) or a delta network (L1, L2 and L3 connected). The measuring unit compares the phase positions of star voltages U _L1-N , U _L2-N and U _L3-N with each other. If the neutral conductor is not connected, it runs via a circuit in the measuring unit 303 synchronously with one of the phases L1, L2 or L3. Via the phase position, the measuring unit 303 calculates whether it is a triangular network or star network.

In another embodiment, the configuration switching unit 302 may also be implemented "manually." For this purpose, instead of processor unit-controlled configuration switches (short-circuit) terminals are used manually during the installation of the dishwasher to achieve the necessary according to the network type interconnection of the conductors L1, L2, L3 and N. In a single-phase voltage network, the conductors L1, L2 and L3 are short-circuited using short-circuit terminals or bridges so that the same phase is applied to all three conductors of the grid connection. In this case, the processor unit 307 may use the measurement results of the measuring device 303, i. Based on the non-existent phase difference (phase difference = 0) recognize that it is a single-phase voltage network.

For a star network, no shorting clamps or bridges need to be provided so that the measurement device 303 can detect the type of network as previously described. For a triangular network, in turn, the conductors L1, L2, L3 and N must be connected by means of short-circuit terminals or bridges in such a way that the (groups of) the consumer elements as in Fig. 6 shown connected to the phases, ie the on-site (not existing) neutral is not used.

Optionally, it would also be conceivable that the plug of the connection cable already correctly transmits the individual phases to the mains connection terminal of the dishwasher.

If short-circuiting bridges are set during the installation of the dishwasher (or a correspondingly configured plug is used), it should be noted that the measuring device 303 can only be connected to the individual conductors L1, L2, L3 and N after this. Accordingly, in this case, the set bridges must be taken into account in detecting the type of mesh from the measuring device 303.

In the in Fig. 3 As shown, the processor unit 307 causes the configuration switching unit 302 in the event that a star network is detected (and thus a neutral), the configuration switches 312 to switch so that they the switches T1-T6 of the switching unit 304 with the neutral Connect N In the event that a triangular network has been detected (and thus no neutral is present), the processor unit 307 causes the configuration switching unit 302 to switch the configuration switches 312 so as to connect the switches T1, T2, T4, T5 and T6 of the switching unit 304 connects to the conductor L3 and T3 to L2. Furthermore, the processor unit 307 causes the configuration switching unit 302, the conductors L1, L2, L3 and N (star network) and conductors L1, L2 and L3 (delta network) with the electrical load elements, ie in the embodiment with the heating coils of the radiator and the circulation pump connect to.

Fig. 4 shows an exemplary interconnection of the electrical consumer elements, ie the four coils (B1.1, B1.2, B1.3 and B1.4) of the boiler radiator, the coil (T1.1) of the Spülbehälterheizkörpers and the circulating pump in Fig. 3 in a star network. Fig. 5 shows an exemplary interconnection of the electrical consumer elements, ie the four coils (B1.1, B1.2, B1.3 and B1.4) of the boiler radiator, the coil (T1.1) of the Spülbehälterheizkörpers and the circulating pump in Fig. 3 in an AC network. Fig. 6 shows the interconnection in a triangle mesh. The switches T1 to T6 show the individual switches of the switching unit 304 in FIG Fig. 3 ,

The configuration of the configuration switches S1-S4 of the configuration switching unit 302 corresponding to each recognized low-voltage network can be stored, for example, at the factory in a memory device 308 of the power controller (for example a ROM, EEPROM, or other readable and optionally writable non-volatile memory). The processor unit 307 may then read the corresponding configuration information for the configuration switches S1-S4 from the memory unit 308 depending on the detected low-voltage network and cause the configuration switching unit 302 to switch the configuration switches S1-S4 accordingly.

As in Fig. 3 As can be seen, the conductors L1, L2, L3 and the neutral conductor N (if provided by the customer) are connected to the electrical load elements such that each of the conductors L1, L2 and L3 and the neutral conductor N (if present on-site) with a group of several consumer elements is connected. Each consumer element is further switchable via a switch of the switching unit 304, wherein the respective switch of the consumer element can be opened and closed by the processor unit 307. As a result, the processor unit 307 can individually control the flow of current through the individual consumer elements. This allows processor unit 307 to selectively control the power supplied to the load elements to the individual process steps of a purge cycle while ensuring that the power consumed by the load elements does not exceed the maximum power provided by the detected low voltage network (optionally less power margin).

The table below shows, by way of example for different grids, how the consumer elements of the tank heater, boiler heater and circulating pump are switched when the boiler is prioritized, if there is a corresponding heating demand. Other combinations are conceivable. The following performances of the individual heating elements and the circulating pump are assumed at a voltage of 230 V _rms . The tank heater has a coil (consumer elements) T1.1 = 2.5 kW. The boiler heater has four coils (load elements) B1.1 to B1.4, with the individual outputs B1.1 = 3 kW, B1.2 = 1.8 kW, B1.3 = 3 kW and B1.4 = 3 kW. The circulation pump (consumer element) UP has a capacity of 1.5 kW. <b> Table 2 </ b> Type of network Circulation phase (priority and heating demand in the boiler) Standby (priority and heating demand in the boiler) Three-phase star network, 400 V, 16 A UP, B1.2, B1.3, B1.4 B1.1, B1.3, B1.4 Three-phase star network, 400V, 32A UP, B1.1, B1.2, B1.3, B1.4, T1.1 B1.1, B1.2, B1.3, B1.4, T1.1 Single-phase AC voltage, 230 V, 32 A. UP, B1.2, B1.3 B1.3, B1.4

Again, it is possible in the memory device of the power controller for the respective, available power in the various types of low-voltage networks and for the various process steps in the rinsing cycle, the respective switch positions of the switches of the switching unit 304 store. The processor unit 307 can here again depending on the detected low-voltage network and the respective process step in the flushing cycle, the corresponding switching information for the switches T1-T6 of the switching unit 304 from the memory unit 308th and cause the switching unit 304 to switch the switches T1-T6 of the switching unit 304 accordingly.

The respective available power in the different types of low-voltage networks depends on the number of phases and the mains voltage and the protection of the low-voltage network, i. the maximum current flow per phase. The protection of the phases can be specified, for example, by a coding circuit during the installation of the dishwasher. Alternatively, the security can also be programmed by the user of the dishwasher and is stored in the storage device. The processor unit 307 is able to read out the coding circuit or to read out the protection of the phases from the memory device in order thus to determine the respective maximum power (per phase) of the recognized low-voltage network. According to the power thus determined (per phase), the processor unit 307 can read out the corresponding switch positions of the switching unit 304 for the respective process steps of the flushing cycle from the memory unit 308 and cause the switching unit 304 to open or close the switches of the switching unit 304 accordingly.

It is also possible that the amount of mains voltage can be indicated by a coding circuit during the installation of the dishwasher or alternatively can be programmed by the user of the dishwasher and stored in the memory device. In this case, it is not necessary for the measuring device 303 to determine the mains voltage of the on-site low-voltage network, but the value can be read out from the coding circuit or the memory device 308 by the processor unit 307.

In another embodiment, it is possible to completely dispense with the measuring device 303. In this case, the type of low voltage network to which the dishwasher is connected and its mains voltage and protection are set by one or more encoding circuits and read out by the processor unit 307 to switch the configuration switching unit 302 and switching unit 304 according to the coded information. Alternatively, instead of the coding circuit (s), the information can be programmed by the user of the dishwasher and stored in the memory unit of the power controller. The processor unit 307 may then read this information and control the configuration switching unit 302 and the switching unit 304 accordingly.

The in Fig. 3 shown exemplary power controller 300 according to an embodiment of the invention is provided with a two-stage switching arrangement. The first stage corresponds to the configuration switching unit 302, which connects the lines L1, L2, L3 and N of the grid connection in dependence on the detected low-voltage network with the electrical load elements. The second stage corresponds to the switching unit 304 and makes it possible to control the power supply to the individual load elements by means of their switches T1-T6. In another embodiment, it is provided to realize these two stages in a single switch arrangement. For this purpose, the power controller 300 comprises instead of the configuration switching unit 302 and switching unit 304 a switching matrix with switches that allow each electrical load element depending on the detected low-voltage network (and the power provided) and depending on the process step of the rinse cycle with one of the conductors L1 , L2 and L3 and the neutral conductor (star network and single-phase AC network) or to connect to two of the conductors L1, L2 and L3 (delta network).

The configuration of the power controller, and in particular the manner in which the configuration switching unit 302 and the switching unit 304 are switched by the processor unit 307 depends, as explained, both on the number and the individual powers of the considered load elements, as well as on the low-voltage network the dishwasher is connected (type of mains, voltage and protection). Of course, the invention is not on the in Fig. 3 shown number of consumer elements, in particular limited to a 4-way boiler heater and a 1-way tank heater. The boiler heater and tank heater may also have more or less heating coils (and thus consumer elements). This can lead to the fact that the power controller 300 can not be implemented on a single power electronic PCB (PCB), but that several power controllers, which in turn can drive different groups of consumer elements, are used in cascade. For this purpose, the individual phases of the low-voltage network can be connected to the mains connection terminal 301 of the parallel-connected power controller 300.

In the case of cascading multiple power controllers, the control electronics (control unit) can be implemented on its own electronic printed circuit board (PCB) and the necessary control information to control the configuration switching units 302 and the switching unit 304 via data bus to the power controller, or their Transmit processor units 307. The power controllers are connected to the control unit with data cables (see data bus connection 306).

Another aspect of the invention relates, as already mentioned, to an energy-saving operation of a (commercial) dishwasher, as described for example in relation to Fig. 1 to 3 has been described. The dishwasher monitors in standby mode the temperature of water required in a rinse cycle provided by a tank or boiler of the dishwasher and ensures that the water temperature does not fall below a certain predetermined temperature. This temperature is chosen so that at the start of a rinse cycle (ie, the rinsing operation is taken and a rinse cycle to go through), the water during the rinse cycle with the desired (target) temperature, at the desired time and optionally in the desired amount (depending on the embodiment) can be provided to allow a hygienic rinsing operation. For example, it is thus possible to monitor the fresh water temperature for rinsing the ware in the boiler and / or the rinse water temperature in the tank of the dishwasher. According to the measured temperature, the dishwasher activates and deactivates the heating of the boiler and / or rinse water tank.

Commercial dishwashers usually have short flush times of only a few minutes. By way of example, it can be assumed that a hygienic cleaning of the items to be washed is ensured by rinsing the item to be washed with hot water from the boiler at the end of a rinsing cycle. Due to the very short flushing times, the fresh water in the boiler must be heated to the desired temperature, approx. 85 ° C, in a correspondingly short time from the power water temperature (approx. 5 ° C - 25 ° C), which is why conventional dishwashers should as far as possible adjust the temperature of the water in the boiler Hold continuously, so keep a water temperature of 85 ° C in standby mode. Similarly, in conventional dishwashers, the water temperature in the dishwasher's washing compartment is maintained at the desired temperature, e.g. about 62 ° C to start the flushing process as possible without delay and complete.

The dishwasher according to an embodiment of the invention allows that during the standby time of the dishwasher, the temperatures of at least the fresh water in the boiler and optionally also the rinsing water in the tank can be lowered and not fall below certain minimum temperatures.

Considering the predetermined temperature for the fresh water, which should not be fallen below, so this is chosen so that in the case of starting a rinse the rinse cycle can be started immediately and completed in the desired time, but still a hygienic cleaning by rinsing with sufficient heated water (eg 85 ° C) is ensured. The predetermined temperature is selected so that the boiler can provide fresh water in the desired amount and at the desired temperature at the beginning of the post-rinse phase in the rinse cycle (or at least for a sufficient time within the rinse phase). For example, assuming a rinse cycle of 2 minutes and assuming, for example, further that the rinse including drainage lasts 16 seconds and 2 liters of hot fresh water are needed, the predetermined temperature, which should not be undershot, chosen so that the The boiler heats the water in the boiler within 104 seconds to the desired temperature of 85 ° C.

Depending on the selection of the boiler volume, residual water may remain in the boiler after removal of the fresh water for the final rinse phase. This in turn means that the predetermined temperature for the fresh water, which should not be undershot, with a smaller boiler volume can be higher than with a larger boiler volume. However, for safety reasons (eg to avoid overheating / burning through of the boiler heater), it may nevertheless make sense to select the boiler volume greater than the amount (volume) of fresh water required in the final rinse phase, for example to ensure that the heating coils are always ) Remain water. Accordingly, the boiler volume may be selected so that, irrespective of the rinse volume selected, the amount of residual water in the boiler after rinsing is constant (e.g., 4.5 liters).

The value of the given fresh water temperature, which should not be undershot, depends inter alia on the power that can be made available to the radiator during the available time span (ie 104 sec in the preceding example). Among other things, this power may depend on the maximum power of the low voltage network (ie voltage, number of phases and their protection). Of course (as explained) also influences the volume of the boiler and the amount of residual water remaining in the boiler, the power of the boiler heater or its coils, the required amount of water, as well as the time available for heating the fresh water to the predetermined temperature should not fall below.

For a dishwasher, as they relate to Fig. 1 to Fig. 3 has been described, the table below for a selection of different services of the low voltage network shows by way of example, which temperature of the fresh water should not fall below in standby mode, so that 2 or 3 liters of fresh water for the 104 seconds after cycle start incipient rinsing with 85 ° C provided can be. Table 3 below assumes that after rinsing, a residual water quantity of 4.5 l will always remain in the boiler. Accordingly, after refilling the boiler 6.5 1 and 7.5 1 fresh water in the boiler, which must be heated and then should not fall below the minimum temperatures shown in Table 3. <b> Table 3 </ b> Type of network tension validation Minimum temperature of the water in the boiler, rinsing volume 2.01 Minimum temperature of the water in the boiler, re-flushing 3.01 Three-phase star network 400V 16 A 54 60 Three-phase star network 400V 25 A 50 55 Three-phase star network 400V 32 A 43 49 Single-phase AC voltage 230V 32 A 67 70

As indicated, it can optionally also be ensured that, within the circulation time of the dishwasher, the rinse water has a certain temperature, for example 62 ° C., for a certain time. For this purpose, for example, a certain rinse water temperature can be set, which should not be undershot in standby mode, so that the rinse cycle can be started immediately and yet the rinse water is available at a desired time of the rinse cycle with the desired temperature. Returning to the example above, for example, it can be assumed that the recirculation time lasts 104 seconds. Accordingly, the certain rinse water temperature, which should not be undershot in the standby mode, can be selected so that at least for a certain time, for example 15, 30 seconds or 45 seconds of recirculation time the rinse water (at least) a certain temperature, eg 62 ° C, owns. As shown in Table 3, it is possible to use different types of low - voltage networks (and optionally for different amounts of flushing water) determine the respective minimum flushing water temperatures, which should not be undershot in standby mode.

The fresh water is often supplied at a temperature below the designated minimum temperature of the fresh water in the boiler. If the grid connection power is low, it may happen that the temperatures required by the user for rinsing can not always be reached at the desired time when the next rinse cycle is started immediately after a rinse cycle has ended. In such a case, the dishwasher may correspondingly extend the rinse cycle or one or more process steps in which a desired temperature is to be achieved until the desired temperatures are reached.

• Netzspannung und Absicherung am Installationsort (beim Kunden),
• Die aktuellen Temperaturen und die gewünschten Zieltemperaturen in Boiler und Spülwassertank,
• Energieverbrauch weiterer Aggregate wie Pumpenmotoren und Wärmepumpen,
• Zeitpunkte, zu denen das Wasser mit den gewünschten Zieltemperaturen im Spülzyklus bereitstehen soll, d.h. die Spülzeiten und Spülprogramm (Spülzyklus)
• Nachspülmenge bzw. Spültankinhalt,
• Restwassermenge, die nach dem Nachspülen im Boiler verbleibt,
• Konfiguration der Spülmaschine durch den Benutzer,
• Einhaltung von EMV Normen, z. B. Netzflicker

In the determination of the respective temperatures, which should not be exceeded by the fresh water in the boiler, or by the rinse water in the rinsing tank, the following dependencies are taken into account in one embodiment of the invention:

• Mains voltage and protection at the installation site (at the customer),
• The current temperatures and the desired target temperatures in boiler and rinse tank,
• Energy consumption of other units such as pump motors and heat pumps,
• Times at which the water should be ready with the desired target temperatures in the rinsing cycle, ie the rinsing times and rinsing program (rinsing cycle)
• Rinse volume or rinse tank contents,
• Residual water remaining in the boiler after rinsing
• Configuration of the dishwasher by the user,
• Compliance with EMC standards, eg. B. Netflicker

The energy management and the temperature control of the dishwasher can be taken over either by the processor unit 307 of the power controller 300 or by the control unit of the dishwasher. If the control unit is used, it transmits the necessary control information via a data bus to the power controller, or its processor unit 307, which assumes the control of the switching unit 304 accordingly. In Fig. 3 a bus connection 306 is indicated, which is a communication between the processor unit 307 and the control unit (see. Fig. 1 and Fig. 2 ).

As discussed in connection with Table 2, for a given low voltage network in the individual process times of the purge cycle (eg recirculation phase and post rinse phase) there may be different combinations in which the consumer elements of the dishwasher can be operated without the maximum power provided by the low voltage network ( if necessary minus a safety margin). If a hygienic rinse is to be achieved by rinsing with clear water, it makes sense to prioritize the boiler heater in the power supply to the tank heater. So it can be ensured that a rinsing cycle the fresh water for rinsing in the desired amount, with the desired temperature and at the desired time in the rinse cycle is provided by the boiler.

If, on the other hand, the hygienic rinsing is to be made possible by a sufficiently high temperature of the rinsing water, then again it makes sense to prioritize the tank heating in the supply of power to the boiler heater. This ensures that in a rinse cycle the rinse water of the rinse water tank with the desired temperature and at the desired time in the rinse cycle from the rinse water tank is provided for rinsing the items to be cleaned.

Claims (15)

1. A dishwasher for operation in various voltage systems, comprising:

   multiple electrical load elements (B1.1-4; T1.1),

   a power controller, and

   a system input terminal (301) having multiple conductors (L1, L2, L3, N) for connecting the power controller to the conductors of the on-site low-voltage system with one or more phases, in particular three phases;

   characterised in that the power controller comprises:

   - means for detecting the type of low-voltage system using the single- or multi-phase system voltage of the low-voltage system which is supplied to the power controller; and

   - a switching unit (304) for electrically connecting the conductors of the system input terminal (301) to groups of the load elements depending on the detected type of low-voltage system, wherein each group comprises at least one load element or multiple parallel-connected load elements and at least one switch (T1-T6) for controlling the power supply to the load elements of the respective group.
2. The dishwasher according to Claim 1, wherein the means for detecting the voltage system comprise:

   a measuring unit (303) for determining the number of phases of the voltage system; and

   a processor unit (307) for detecting the type of voltage system using the determined number of phases.
3. The dishwasher according to Claim 2,
   wherein the measuring unit (303) is adapted to determine the relative angle of the phases and/or the system voltage of the low-voltage system, and
   the processor unit (307) is adapted to detect the type of low-voltage system using the determined number of phases and using the relative phase angle and/or the system voltage.
4. The dishwasher according to Claim 2 or 3, wherein the processor unit (307) is adapted to switch the switches (T1-T6) of the groups of electrical load elements such that the total current supplied to the electrical load elements does not exceed the fusing of the low-voltage system, optionally taking into account a safety margin,
   wherein the power supply to each load element in at least one of the groups of electrical load elements can be controlled individually with a switch (T1-T6) by the processor unit (307).
5. The dishwasher according to Claim 4, wherein the processor unit (307) is adapted to switch the power supply to the electrical load elements by means of the switches (T1-T6) of the groups of electrical load elements depending on the process step of the respective washing cycle of the dishwasher.
6. The dishwasher according to any one of Claims 2 to 5, wherein the processor unit is adapted to read the fusing of the low-voltage system from a memory of the power controller or of the dishwasher, or a coding circuit manually coded according to the fusing.
7. The dishwasher according to any one of Claims 1 to 6, wherein the power controller comprises a memory (308) which stores configuration information which indicates how the processor unit (307) must cause the switching unit (304) to switch the switches of the individual groups of electrical load elements depending on the detected type of low-voltage system and the fusing thereof so that the power of the low-voltage system is distributed to the electrical load elements of the dishwasher such that the total current does not exceed the fusing of the low-voltage system, optionally taking into account a safety margin.
8. The dishwasher according to Claim 7, wherein the memory (308) stores the resistance values of the individual electrical load elements of the dishwasher.
9. The dishwasher according to either of Claims 7 or 8, wherein the processor unit (307) is adapted to read configuration information from the memory (308) for the relevant detected low-voltage system and the fusing thereof and to switch the switches of the setting unit using the read configuration information,
   wherein the processor unit (307) is adapted to read the voltage of the low-voltage system from a memory (308) of the power controller or of the dishwasher.
10. The dishwasher according to any one of Claims 1 to 9, wherein the switching unit (304) is adapted to connect each phase of the system voltage to a group of electrical load elements in a switchable manner.
11. The dishwasher according to Claim 10, wherein the switching unit (304) has switches (S1-S4) for connecting each phase of the system voltage to a group of electrical load elements, and
    wherein the processor unit (307) is adapted to switch the switches (S1-S4) depending on the detected type of low-voltage system to electrically connect the conductors of the system input terminal (301) to groups of the load elements depending on the detected type of low-voltage system.
12. The dishwasher according to any one of Claims 1 to 11, wherein the switching unit (304) also comprises switches (S1-S4) to short-circuit individual conductors of the system input terminal (301), and the processor unit (307) is adapted to switch the switches (S1-S4) depending on the detected type of low-voltage system in order to short-circuit individual conductors of the system input terminal (301) to each other.
13. The dishwasher according to any one of Claims 1 to 12, wherein the power controller comprises multiple power regulators, in particular a pulse width modulator, for the load elements in order to reduce the power output at the load elements, wherein each power regulator is adapted to supply the reduced power to one or more of the electrical load elements.
14. The dishwasher according to any one of Claims 1 to 13, wherein the dishwasher also comprises a control unit which communicates via a data bus with the processor unit (307) of the power controller, and
    the processor unit (307) is adapted to receive from the control unit control signals for the electrical load elements of the dishwasher and to control the supply of power to the respective load elements in accordance with the control signals.
15. The dishwasher according to any one of Claims 1 to 14, wherein the system input terminal (301) and/or the respective connections of the load elements of the dishwasher are in the form of a detachable connection element, in particular a plug.

Images