JP2975848B2 - Cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device such as a low-temperature showcase or a refrigerator.

[0002]

2. Description of the Related Art Conventionally, this type of cooling device has been disclosed in, for example, Japanese Patent Publication No. 4-32311 (F25D13 / 0).
0), as shown in FIG.
Or, an alarm device such as a buzzer at an abnormally low temperature
Is configured to be driven. In addition, 4-54
In Japanese Patent Publication No. 158 (F25D21 / 08), energization to the compressor and the defrost heater is selectively switched by a defrost timer, and each operation (heat generation) is controlled.

[0003] When a rotary compressor is used as a compressor of this type of cooling apparatus, the compression is performed when the phases (R phase, S phase, T phase) of the three-phase AC power supplied to the compressor are reversed. The machine rotates reversely. Therefore, in the conventional cooling device, a reverse-phase prevention relay and a phase changeover switch that open the contact by detecting the reverse-phase connection of the three-phase AC power supply are provided, and the power to the compressor is prohibited during the reverse-phase connection. In addition to preventing reverse rotation, the configuration is such that normal phase connection can be switched by the phase switch.

[0004]

The use of such a reverse-sequence prevention relay can reliably prevent the compressor from rotating in the reverse direction. Because the compressor just doesn't start running,
As a user, there is a problem that it is easy to misunderstand that another device is out of order, and that the user feels useless. In particular, when the compressor is started with a delay after the power is turned on, the abnormality is found after the delay period has elapsed, so that the usability is further deteriorated.

For this reason, a special display lamp or the like which is lit in the reverse-phase connection has conventionally been attached so that the user can immediately confirm the reverse-phase connection. However, this is due to the complicated wiring and an increase in the number of parts. There was a problem that caused the cost to rise.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional technical problem, and prevents the reverse rotation of the compressor due to the reverse-phase connection of the power supply, and also prevents the power supply from increasing without increasing the number of parts. It is an object of the present invention to provide a cooling device that can promptly notify a user of the reverse-phase connection.

[0007]

According to a first aspect of the present invention, there is provided a cooling apparatus comprising: a rotary compressor and a defrost heater connected to a three-phase AC power supply; and a power supply to the compressor and the defrost heater. A defrost timer having a changeover contact for controlling the battery in a unified manner, and a reverse-phase prevention relay that detects a reverse-phase connection of the power supply and opens the contact. The contact of the reverse-phase prevention relay and the defrost timer are provided. Are connected in series to a power supply.

[0008] The cooling device according to a second aspect of the present invention is characterized in that, in the above, the defrost timer has a display which is energized and turned on.

A cooling device according to a third aspect of the present invention is a rotary compressor connected to a three-phase AC power supply, and detects a reverse-phase connection of the power supply and opens a contact to inhibit power supply to the compressor. A circuit connection that has a phase prevention relay and an alarm device that warns of an abnormality other than the reverse phase connection that occurred in the cooling device, and that operates even if the contact of the reverse phase prevention relay opens. It is what it was.

[0010]

According to the first aspect of the present invention, the contact of the anti-phase prevention relay and the defrost timer are connected in series with the power supply.
When the power supply is connected in reverse phase, the contact of the reverse-phase prevention relay opens and the defrost timer is not energized, so that energization of the compressor is also prohibited. Therefore, the reverse rotation of the compressor due to the reverse phase connection of the power supply can be reliably prevented. In particular, since the defrost timer is de-energized and does not operate during reverse-phase connection, the user can immediately recognize the reverse-phase connection depending on the operation state of the defrost timer. Therefore, it is possible to eliminate the need for a special display lamp or the like for displaying a reversed phase.
Wiring can be simplified and cost can be reduced.

According to the second aspect of the present invention, since the defrost timer has the display which lights up when the power is supplied, the reverse phase connection of the power supply is used depending on the lighting state of the display of the defrost timer. Can be promptly and reliably notified to the person.
That is, since the occurrence of the reverse phase connection can be warned by also using the indicator of the defrost timer, a special display lamp or the like for the reverse phase display becomes unnecessary, so that the wiring can be simplified and the cost can be reduced. become.

According to the third aspect of the present invention, in the case where an alarm device for warning other abnormalities other than the reverse phase connection generated in the cooling device is provided, when the contact of the reverse phase prevention relay is opened. Since the alarm device operates in a circuit connection, the reverse phase prevention relay prevents the compressor from rotating in the reverse phase when the power supply is connected in reverse phase, while also using another alarm device to warn of the occurrence of reverse phase connection. become able to. Therefore, the user can be notified of the reverse phase connection of the power supply promptly and reliably to the user, and no special display lamp or the like for displaying the reverse phase is required.
This enables simplification of wiring and reduction of cost.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an electric circuit diagram of a low-temperature showcase 1 as an embodiment of a cooling device to which the present invention is applied, FIG. 2 is a perspective view of the low-temperature showcase 1, FIG.
FIG. 4 shows longitudinal side views of the low-temperature showcase 1.

In each of the figures, a low-temperature showcase 1 is used for displaying and preserving ice cream or the like in a food store or a supermarket of a department store, for example. It is configured. This heat insulation box 2 is made of a metal outer box 3.
And a metal inner box 6 incorporated in the outer box 3 with a space therebetween, and a heat insulating material 7 such as polyurethane foam filled between the two boxes 3 and 6 by a foaming method in place. ing.

Duct plates 8 and 9 are attached to the inside of the opposing side walls of the inner box 6 at intervals, and a bottom plate 11 is detachably mounted between lower ends of the duct plates 8 and 9.
As a result, a series of ducts 12 standing up and down from the bottom surface are formed inside the inner box 6, and a storage room 22 is defined inside these duct plates 8, 9 and the bottom plate 11,
A basket 51 is detachably mounted in the storage room 22. On the other hand, the bottom wall 13 of the heat-insulating box 2 has a stepped shape having a lower portion 13A and a higher portion 13B arranged in the front-rear direction, and the bottom plate 11 is located above the higher portion 13B.

A drain pan 14 is provided on the upper surface of the lower portion 13A, and a drain hole 16 is formed at the lowest position of the drain pan 14 and communicates with the outside of the heat-insulating box 2 below. On the drain pan 14, the duct 12
And a horizontally long plate fin type cooler 17 included in the refrigerant circuit of the refrigeration cycle,
A fan 19 composed of a suction type propeller fan is mounted in a fan case 18 provided on the drain hole 16 side of the fan 7.

The stepped portion between the high portion 13B and the low portion 13A has an inclined surface 13C so that the upper portion is separated from the cooler 17. The upper end of the duct plate 9 is a discharge port 9A, the upper end of the duct plate 8 is a suction port 8A, and an inwardly curved wind direction plate 21 is attached to the discharge port 9A at predetermined intervals.

On the other hand, stainless steel decorations 43 are attached to the periphery of the opening of the heat insulating box 2. Further, kick plates 26, 26 having a large number of through-holes 24,... Are attached around the lower end of the heat insulating box 2, and are located between the kick plates 26, 26 and below the heat insulating box 2. Defines a machine room 27. A rotary compressor 52, a condenser 53 and a blower 54 for the condenser, which constitute a refrigerant circuit of the refrigerating cycle together with the cooler 17, are provided in the machine room 27 located below the high-order portion 13B. And so on.

The rear of the machine room 27 has panels 36, 38
, And a plurality of slits 39 are formed on the right side of the panel 36 and the panel 38. The compressor 52 and the condenser 53 are located behind the panels 36 and 38 at positions corresponding to the slits 39, and the electrical box 30 is located behind and to the left of the panel 36. A defrost timer 56 is provided near the electrical box 30.
The defrost timer 56 has a display (LED) for displaying time.
The display 57 is exposed to the outside through a rectangular window hole 58 formed in the panel 36.

Next, in FIG. 1, two phase change switches (SW) are provided for the A-phase and the R-phase of a three-phase AC 200 V power supply AC composed of a T-phase (AT), an S-phase (AS) and an R-phase (AR). )
61 is connected, a motor (FM2) 19M for driving the blower 19 is connected between the S phase and the R phase, and a motor (FM1) 54M for driving the blower 54 for the condenser is further provided.
It is connected in series with the normally open contact 62B of the compressor magnet switch (CMG) 62. The following circuit is connected to the subsequent stage (common contact) of the phase changeover switch 61 and the S phase of the power supply AC.

That is, the S-phase terminal of the motor (CM) 52M for driving the compressor 52 is connected to the S-phase of the power supply AC, and the R-phase terminal and the T-phase terminal are thermal relays 63, 63.
And normally open contacts 62A, 62A of the magnet switch 62
Is connected to the phase changeover switch 61 via the. A drain pan heater (PH) 66 is provided in the S phase of the power supply AC.
Is connected to the drain pan heater 66. Defrost heaters (DH) 67, 67 are connected to the overheat protector (OHP) 6 respectively.
8 and the normally open contact 69 of the defrosting magnet switch 69
A is connected to the phase change switch 61 via A.

Further, an N-phase prevention relay (NPR) 71 is connected to the S-phase and phase switch 61 of the power supply AC. The anti-phase prevention relay 71 is connected to the motor 5 of the compressor 52.
The contact 71A is opened when a phase (reverse phase) power AC in which 2M rotates in the reverse direction is applied. And this contact 7
1A, the defrost timer (DT) 56, the drain timer (T) 72, the thermostat (TH) 73, the internal thermo 74, the normally closed contact 63 of the thermal relay 63
A, delay timer 76 and magnet switches 62 and 69
Are connected to the phase switch 61.

The defrost timer 56 has a switching contact 56A (common terminal No. 3, switching terminal No. 4, No. 2), a timer motor (TM) 56M and the indicator 57, and a common terminal of the switching contact 56A. Are connected to a contact 71A, and the contact 71A is connected to one phase change switch 61.
The timer motor 56M of the defrost timer 56 and the display 57 are connected in parallel to the common terminal and the other phase switch 61.
The contact 71A and the defrost timer 56 are connected in series to the power supply AC.

The drain timer 72, thermostat 73, internal thermo 74, normally closed contact 63A, delay timer 76, and magnet switch 62 are connected in series between the fourth terminal of the defrost timer 56 and the other phase switch 61. Connected to the second terminal and the other phase switch 61
The magnet switch 69 is connected between them.

The overheat protector (OHP) 68 opens a contact at a predetermined defrosting end temperature of the cooler 17 to cut off the power supply. The drain timer 72 secures a drain time of 5 minutes at power-on and at the end of defrosting. The internal thermo 74 opens a contact due to an abnormally high temperature of the compressor 52. Normally, the magnet switch 62 is energized with a delay of 2 to 3 seconds to prevent chattering.

Next, the operation of the low-temperature showcase 1 having the above configuration will be described. Now, the switching contact 56A of the defrost timer 56
Is closed to the fourth terminal. If the normal phase power supply AC is applied, the contact 71A of the anti-phase prevention relay 71 is also closed, so that the timer motor 56M of the defrost timer 56 and the display 57 are energized and the timer motor 56M The rotation starts, and the indicator 57 lights up.
The user can confirm that the power supply AC has been normally applied by turning on the display 57.

When the thermostat 73 is closed, the magnet switch 62 is energized, and the contacts 62A and 62A
B closes and the motors 52M and 54M are energized. Thereby, when the compressor 52 (and the blower 54) is operated normally (forward rotation), the blower 19 is continuously operated.
C blows up the inside of the duct 12, and is discharged from the discharge port 9 </ b> A at the upper end of the duct plate 9 toward the upper part of the storage room 22. The cool air circulated in the storage room 22 is sucked into the duct 12 from the suction port 8 </ b> A at the upper end of the duct plate 8, and circulates back to the blower 19.

When the temperature of the suction cold air detected by the thermostat 73 decreases to, for example, -22 ° C. due to the cooling, the thermostat 73 opens and the contacts 62A and 62B open, so that the motors 52M and 54M stop. Then, when the suction cool air temperature rises to, for example, −20 ° C., the thermostat 73 is closed again, and the motors 52M and 54M are started. Thereby, the inside of the storage room 22 is cooled to the set temperature of -21 ° C. on average.

Then, when, for example, 12 hours have elapsed from the start of energization of the timer motor 56M, the switching contact 56A of the defrost timer 56 switches to the second terminal. As a result, the power supply to the magnet switch 62 is cut off, and the operation of the motor 52M of the compressor 52 is prohibited. Instead, since the magnet switch 69 is energized, the normally open contact 69A
Is closed, and the drain pan heater 66 and the defrost heaters 67 and 6 are closed.
7 and the defrost of the cooler 17 is started. Then, when the temperature of the cooler 17 rises to, for example, −10 ° C., or when, for example, 45 minutes have passed since the start of defrosting, each heater 6
The energization of the switches 6 and 67 is stopped, the defrost ends, and the switching contact 56A returns to the No. 4 terminal a predetermined time after the start of the defrost.

Here, if the power supply AC is turned on (connected to the outlet) and the phase is reversed, the contact 71A of the reverse phase prevention relay 71 is open. By opening the contact 71A, the defrost timer 56 and the magnet switches 62, 6
9 is cut off, the contact 62A is open,
Therefore, the operation of the motor 52M of the compressor 52 is prohibited. As a result, the motor 5 is connected in reverse phase with the power supply AC.
2M reverse rotation is prevented. Further, since the power supply to the defrost timer 56 is also cut off, the timer motor 56M does not operate, and the display 57 does not light.

The timer motor 56M of the defrost timer 56
, And the display 57 is turned off, so that the user can be quickly and reliably notified of the reverse-phase connection of the power supply AC to the user. That is, since the user can also use the indicator 57 of the defrost timer 56 to warn the user of the occurrence of the reverse phase connection, a special display lamp or the like for displaying the reverse phase is not required, thereby simplifying the wiring and reducing the cost. You can plan. When the reverse phase connection occurs, the phase switch 61 is switched. As a result, the T phase and the R phase are exchanged, so that normal phase connection is established, the contact 71A of the reverse phase prevention relay 71 is closed, and the compressor 52 can be operated as described above.

Next, FIG. 5 shows another electric circuit of the low-temperature showcase 1. In this figure, components denoted by the same reference numerals as those in FIGS. 1 to 4 are the same. In this case, in addition to the circuit of FIG. 1, a defrost display lamp (OL) 81, a high temperature alarm board (PCB) 82 in the refrigerator, a high temperature alarm lamp (RL) 83 in the refrigerator, and auxiliary relays (1X, 2X) 84, 86. ,
Filter sensor (PTH) 87, dew-proof heater (WH)
88, instantaneous return type buzzer stop switch (SW1) 8
9, an alarm buzzer 91 and a filter sign lamp 92 are provided.

The defrost lamp 81 is connected in parallel with the defrost magnet switch 69, and lights up while the cooler 17 is being defrosted. The high temperature alarm board 82 in the refrigerator is provided with a power transformer 82T.
The power transformer 82T is connected to the phase change switch 61 in series with the contact 71A of the reverse phase prevention relay 71. When the temperature of the storage room 22 is low, the contact 82S is opened when the power supply transformer 82T is energized, and the temperature of the storage room 22 is abnormally high (for example, -5 ° C. or higher). ), The contact 82S is closed, and even when the power transformer 82T is not energized, the contact 82S is closed.

A parallel circuit of a high temperature alarm lamp 83 and an auxiliary relay 84 is connected to a phase switch 61 in series with a contact 82S of the high temperature alarm board 82. The filter sensor 87 detects the clogging of the dust removing filter of the condenser 53 and closes the contact. The filter sign lamp 92 is connected in series to the filter sensor 87. Further, the alarm buzzer 91
Are the normally closed contact 86A of the auxiliary relay 86 and the auxiliary relay 84
Is connected in series with the switching contact 84A, and the normally closed terminal of the switching contact 84A is connected between the filter sine lamp 92 and the filter sensor 87.

Buzzer stop switch 89 and auxiliary relay 86
Is connected in parallel to a series circuit of an alarm buzzer 91 and a contact 86A, and a normally open contact 86B of an auxiliary relay 86 is further connected to the buzzer stop switch 89 in parallel.
The anti-dew heater 88 is connected to the phase switch 61 and is continuously energized while the power is turned on.

Operations of the above configuration other than the circuit components shown in FIG. 1 will be mainly described. Assuming that the contact 71A of the anti-phase prevention relay 71 is closed, when the temperature of the storage room 22 abnormally rises and reaches the high temperature due to a failure of the compressor 52 or the like, the contact 82S of the internal high temperature alarm board 82 Is closed, and the inside high temperature alarm lamp 83 is energized and turned on. Since the auxiliary relay 84 is also energized, the switching contact 84A
Is closed to the normally open terminal, and the alarm buzzer 91 is also energized and sounds. When the filter of the condenser 53 is clogged, the filter sensor 87 is closed, so that the filter sign lamp 92 is energized and turned on, and the alarm buzzer 91 is also energized and sounds.

By the alarms generated by the operation of the lamps 83 and 92 and the alarm buzzer 91, the user can quickly and reliably recognize the abnormal temperature of the storage room 22 and the filter clogging of the condenser 53. If the buzzer stop switch 89 is closed, the auxiliary relay 86 is energized and the contact 8
Since 6A is opened, the sounding of the alarm buzzer 91 is stopped.
However, the lamps 83 and 92 continue to be lit unless the abnormality is eliminated, and are turned off by the elimination.
Is also de-energized and returns to the initial state.

Here, when the power supply AC is turned on (connected to the outlet) as described above, when the phase is reversed, the contact 71A of the reverse phase prevention relay 71 is open as in the case described above. When the contact 71A is opened, the power to the defrost timer 56 and the magnet switches 62 and 69 is cut off.
2A is open and therefore the motor 52M of the compressor 52
Driving is prohibited. This prevents reverse rotation of the motor 52M due to the reverse phase connection of the power supply AC. In addition, since the power supply to the defrost timer 56 is also cut off, the timer motor 56M does not operate, and the display 57 does not light up.

The transformer 8 of the high temperature alarm board 82
Since 2T is also de-energized, the contact 82S is closed as described above, and the high-temperature warning lamp 83 is energized and turned on. Since the auxiliary relay 84 is also energized, the switching contact 84A
Is closed to the normally open terminal, and the alarm buzzer 91 is also energized and sounds. In other words, the operation of the in-compartment high-temperature alarm lamp 83 and the alarm buzzer 91 can promptly and reliably notify the user of the reverse-phase connection of the power supply AC to the user. In particular, a user can be alerted to the occurrence of reverse-phase connection by using the high-temperature alarm board 82, the high-temperature alarm lamp 83, and the alarm buzzer 91 for notifying abnormalities other than reverse-phase connection to the user. This eliminates the need for special display lamps and the like, thereby simplifying wiring and reducing costs.

In the embodiment, the present invention is applied to a low-temperature showcase. However, the present invention is not limited to this, and is effective for refrigerators, air conditioners, and other various cooling devices. Further, in the embodiment, the high-temperature warning board in the refrigerator is used to warn of the reverse phase connection of the power supply. However, the present invention is not limited to this, and a filter sensor or the like may be used.

[0041]

As described above in detail, according to the first aspect of the present invention, the contact of the anti-phase prevention relay and the defrost timer are connected in series with the power supply. Since the contact of the phase prevention relay opens and the defrost timer is not energized, energization of the compressor is also prohibited. Therefore, the reverse rotation of the compressor due to the reverse phase connection of the power supply can be reliably prevented. In particular, since the defrost timer is de-energized and does not operate during reverse-phase connection, the user can immediately recognize the reverse-phase connection depending on the operation state of the defrost timer. Therefore, it is possible to eliminate the need for a special display lamp or the like for reverse phase display, thereby simplifying the wiring and reducing the cost.

Further, according to the second aspect of the present invention, in addition to the above, the defrost timer has a display which is turned on when the power is turned on. The user can be notified of the phase connection promptly and reliably. That is, since the occurrence of the reverse phase connection can be warned by also using the indicator of the defrost timer, a special display lamp or the like for the reverse phase display becomes unnecessary, so that the wiring can be simplified and the cost can be reduced. become.

According to the third aspect of the present invention, in the apparatus provided with an alarm device for warning an abnormality other than the reverse-phase connection occurring in the cooling device, the contact of the reverse-phase prevention relay is opened. In this case, a reverse-phase prevention relay prevents reverse rotation of the compressor during reverse-phase connection of the power supply, and the reverse-phase connection occurs by using another alarm device. Can be warned. Therefore, the user can be notified of the reverse phase connection of the power supply promptly and reliably to the user, and no special display lamp or the like for displaying the reverse phase is required, thereby simplifying the wiring and reducing the cost. That is what you can do.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a low-temperature showcase as an embodiment of a cooling device of the present invention.

FIG. 2 is a perspective view of a low-temperature showcase as an embodiment of the cooling device of the present invention.

FIG. 3 is a front view of a low-temperature showcase as an embodiment of the cooling device of the present invention.

FIG. 4 is a vertical sectional side view of a low-temperature showcase as an embodiment of the cooling device of the present invention.

FIG. 5 is another electric circuit diagram of a low-temperature showcase as an embodiment of the cooling device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low-temperature showcase 52 Compressor 52M Motor 56 Defrosting timer 57 Display 61 Phase change switch 71 Reverse phase prevention relay 71A Contact 82 High temperature alarm board in a chamber 83 High temperature alarm lamp in a chamber 91 Alarm buzzer AC Three-phase 200V AC power supply

Claims (3)

(57) [Claims] 1. A defroster comprising: a rotary compressor and a defrost heater connected to a three-phase AC power supply; and a switching contact for selectively controlling energization of the compressor and the defrost heater. A timer and a reverse-phase prevention relay that opens a contact by detecting a reverse-phase connection of the power supply, and the contact of the reverse-phase prevention relay and the defrost timer are connected in series to the power supply. And cooling device. 2. The cooling device according to claim 1, wherein the defrost timer has a display that is turned on when energized. 3. A rotary compressor connected to a three-phase AC power supply, a reverse-phase prevention relay that detects a reverse-phase connection of the power supply, opens a contact, and prohibits energization of the compressor.
An alarm device for warning other abnormalities other than the reverse-phase connection generated in the cooling device, wherein the alarm device operates even when the contact of the reverse-phase prevention relay is opened. Characterized cooling device.