CN212130757U - Water pump control circuit - Google Patents

Abstract

The utility model provides a water pump control circuit, including first motor, second motor and third motor, a serial communication port, still include control power supply, main control circuit, first motor drive return circuit, second motor drive return circuit, third motor drive return circuit and liquid level indication return circuit, this first motor drive return circuit is connected with first change over switch, this second motor drive return circuit is connected with second change over switch, this liquid level indication return circuit is used for obtaining to make first motor drive return circuit behind the predetermined water level signal, in second motor drive return circuit and the third motor drive return circuit arbitrary two circuits by the automatic switch-on after with drive this first motor, arbitrary two motors in this second motor and this third motor carry out work.

Description

Water pump control circuit

Technical Field

The utility model relates to a water pump control circuit.

Background

The scheme that one water pump is used and one water pump is used for two water pumps is adopted conventionally in daily use, but when one water pump breaks down and needs to be maintained, only one water pump cannot meet the use requirement, particularly, the problem is increased due to the fact that the time for maintaining the broken-down water pump is too long, more and more situations need to be generated when three water pumps work and are used alternately in some occasions, namely, any two of the three water pumps are at least guaranteed to work, and at the moment, a set of control mode scheme meeting the requirement that the three water pumps are alternated is required to be generated.

Therefore, a new technical solution is provided to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a water pump control circuit.

The utility model discloses a technical scheme as follows:

a water pump control circuit comprises a first motor, a second motor and a third motor, and is characterized by further comprising a control power supply, a main control loop, a first motor driving loop, a second motor driving loop, a third motor driving loop and a liquid level indicating loop, wherein the main control loop is connected with the control power supply, the first motor driving loop is connected with the first motor, the second motor driving loop is connected with the second motor, the third motor driving loop is connected with the third motor, the liquid level indicating loop, the first motor driving loop, the second motor driving loop and the third motor driving loop are respectively connected with the main control loop to obtain a circuit power supply, and the first motor driving loop, the second motor driving loop and the third motor driving loop are respectively connected with the liquid level indicating loop; the motor driving circuit also comprises a first change-over switch, a second change-over switch and a third change-over switch, wherein one end of a gear contact on the first change-over switch is connected with the main control loop, the other end of the gear contact on the first change-over switch is connected with the first motor driving loop, one end of a gear contact on the second change-over switch is connected with the main control loop, the other end of the gear contact on the second change-over switch is connected with the second motor driving loop, one end of a gear contact on the third change-over switch is connected with the main control loop, and the other end of the gear contact on the third change-over switch is connected with the third motor driving loop; the liquid level indicating loop is used for enabling any two circuits in the first motor driving loop, the second motor driving loop and the third motor driving loop to be automatically switched on after a preset water level signal is obtained so as to drive any two motors in the first motor, the second motor and the third motor to work.

The water pump control circuit is characterized in that the control power supply is a three-phase alternating current power supply, the main control loop comprises a main switch 0QF, a circuit control switch 1QF, a circuit control switch 2QF, a circuit control switch 3QF, an alternating current contactor 1KM, an alternating current contactor 2KM, an alternating current contactor 3KM, a thermal relay 1KH and a thermal relay 2KH, the circuit control switch 1QF, the circuit control switch 2QF and the circuit control switch 3QF are respectively connected with the control power supply and the main switch 0QF, a main contact of the circuit control switch 1QF, a normally open contact 1KM-1 (not shown in the figure) of the alternating current contactor 1KM, the thermal relay 1KH and the first motor are sequentially connected, a main contact of the circuit control switch 2QF, a normally open contact 2KM-1 (not shown in the figure) of the alternating current contactor 2KM, the thermal relay 2KH and the second motor are sequentially connected, the main contact of the circuit control switch 3QF, the normally open contact 3KM-1 (not shown in the figure) of the ac contactor 3KM, the thermal relay 3KH and the third motor are connected in sequence, a phase a in the three-phase wiring port on the main switch 0QF leads out a power line L1, a phase a in the three-phase wiring port on the circuit control switch 1QF leads out a power line L11, a phase a in the three-phase wiring port on the circuit control switch 2QF leads out a power line L21, and a phase a in the three-phase wiring port on the circuit control switch 2QF leads out a power line L31.

The water pump control circuit is characterized in that the first change-over switch, the second change-over switch and the third change-over switch are all provided with a first automatic gear, a second automatic gear, a manual gear and a standby gear.

The water pump control circuit comprises a first motor driving loop, a second motor driving loop and a third motor driving loop, wherein the first motor driving loop comprises a manual switch 1SS, a manual switch 1SF, an energizing coil Q1 of an alternating current contactor 1KM, a normally closed contact 1KH-1 of a thermal relay 1KH, a normally open contact 1KA-1 of an intermediate relay 1KA, a normally open contact 2KA-1 of an intermediate relay 2KA, a normally open contact 4KA-1 of an intermediate relay 4KA and a normally open contact 1KM-2 of an alternating current contactor 1KM, a fuse FU1 is connected to a power line L11, a first automatic gear end, a second automatic gear end, a manual gear end and a standby gear end of a first change-over switch are all connected with the fuse FU1, the other manual gear end of the first change-over switch, the manual switch 1SS, the manual switch 1SF, the energizing coil Q1, the normally closed contact 1KH-1 and a neutral line N are sequentially, this normally open contact 1KA-1, this normally open contact 2KA-1, this normally open contact 4KA-1 and this circular telegram coil Q1 interconnect, this normally open contact 1KM-2 is connected with this circular telegram coil Q1, this normally open contact 1KA-1 is connected with this first change over switch's first automatic gear other end, this normally open contact 2KA-1 is connected with this first change over switch's the automatic gear other end of second, this normally open contact 4KA-1 is connected with this first change over switch's reserve gear other end.

The water pump control circuit comprises a second motor driving loop, a first motor driving loop and a second motor driving loop, wherein the second motor driving loop comprises a manual switch 2SS, a manual switch 2SF, an energizing coil Q2 of an alternating current contactor 2KM, a normally closed contact 2KH-1 of a thermal relay 2KH, a normally open contact 1KA-2 of an intermediate relay 1KA, a normally open contact 2KA-2 of the intermediate relay 2KA, a normally open contact 4KA-2 of an intermediate relay 4KA and a normally open contact 2KM-2 of the alternating current contactor 2KM, a fuse FU2 is connected to the power line L21, a first automatic gear end, a second automatic gear end, a manual gear end and a standby gear end of the second change-over switch are all connected with the fuse FU2, the other manual gear end of the second change-over switch, the manual switch 2SS, the manual switch 2SF, the coil Q2, the normally closed contact 2KH-1 and a neutral line N are sequentially, this normally open contact 1KA-2, this normally open contact 2KA-2, this normally open contact 4KA-2 and this circular telegram coil Q2 interconnect, this normally open contact 2KM-2 is connected with this circular telegram coil Q2, this normally open contact 1KA-2 is connected with this second change over switch's first automatic gear other end, this normally open contact 2KA-2 is connected with this second change over switch's the second automatic gear other end, this normally open contact 4KA-2 is connected with this second change over switch's reserve gear other end.

The water pump control circuit, wherein the third motor driving loop comprises a manual switch 3SS, a manual switch 3SF, an energizing coil Q3 of an alternating current contactor 3KM, a normally closed contact 3KH-1 of a thermal relay 3KH, a normally open contact 1KA-3 of an intermediate relay 1KA, a normally open contact 2KA-3 of an intermediate relay 2KA, a normally open contact 4KA-3 of an intermediate relay 4KA and a normally open contact 3KM-2 of an alternating current contactor 3KM, a fuse FU3 is connected to the power line L31, a first automatic gear end, a second automatic gear end, a manual gear end and a standby gear end of the third transfer switch are all connected with the fuse FU3, the other manual gear end of the third transfer switch, the manual switch 3SS, the manual switch 3SF, the energizing coil Q3, the normally closed contact 3KH-1 and a neutral line N are sequentially connected, this normally open contact 1KA-3, this normally open contact 2KA-3, this normally open contact 4KA-3 and this circular telegram coil Q3 interconnect, this normally open contact 3KM-2 is connected with this circular telegram coil Q3, this normally open contact 1KA-3 is connected with this third change over switch's first automatic gear other end, this normally open contact 2KA-3 is connected with this third change over switch's the second automatic gear other end, this normally open contact 4KA-3 is connected with this third change over switch's reserve gear other end.

The water pump control circuit, wherein, the liquid level indicating loop includes a liquid level indicating switch 4SL, a liquid level indicating switch 1SL, a liquid level indicating switch 2SL, a liquid level indicating switch 3SL, one end of the liquid level indicating switch 4SL is connected with the live wire L1, the other end of the liquid level indicating switch 4SL is respectively connected with one end of the liquid level indicating switch 1SL, one end of the liquid level indicating switch 2SL, one end of the liquid level indicating switch 3SL, one end of the normally open contact 1KA-4 of the intermediate relay 1KA, one end of the normally open contact 2KA-4 of the intermediate relay 2KA and one end of the normally open contact 3KA-1 of the intermediate relay 3KA, one end of the liquid level indicating switch 1SL is connected with one end of the energizing coil Q4 of the intermediate relay 1KA, the other end of the energizing coil Q4 is connected with the center line N, the other end of the normally open contact 1KA-4 is connected with the energizing coil Q, one end of the liquid level indicating switch 2SL is connected with one end of a powered coil Q5 of the intermediate relay 2KA, the other end of the powered coil Q5 is connected with the central line N, the other end of the normally open contact 2KA-4 is connected with the powered coil Q5, one end of the liquid level indicating switch 3SL is connected with one end of a powered coil Q6 of the intermediate relay 3KA, the other end of the powered coil Q6 is connected with the central line N, and the other end of the normally open contact 3KA-1 is connected with the powered coil Q6.

The water pump control circuit further comprises a standby delay loop, two ends of the standby delay loop are respectively connected to the power line L1 and a neutral line N, and the motor fault indication loop comprises a normally open contact 1KA-5 of the intermediate relay 1KA, a normally open contact 2KA-5 of the intermediate relay 2KA, a normally open contact 1KA-6 of the intermediate relay 1KA, a normally open contact 2KA-6 of the intermediate relay 2KA, a normally open contact 1KA-7 of the intermediate relay 1KA, a normally open contact 2KA-7 of the intermediate relay 2KA, a normally open contact 1KM-3 of the alternating current contactor 1KM, a normally open contact 2KM-3 of the alternating current contactor 2KM, a normally open contact 3KM-3 of the alternating current contactor 3KM and a coil Q7 for energizing the time relay KT; one end of a first automatic gear of the first change-over switch is connected with the power line L1, the other end of the first automatic gear of the first change-over switch, the normally open contact 1KA-5, the normally open contact 1KM-3 and one end of the electrified coil Q7 are sequentially connected, the other end of the electrified coil Q7 is connected with the neutral line N, one end of a second automatic gear of the first change-over switch is connected with the power line L1, and the other end of the second automatic gear of the first change-over switch, the normally open contact 2KA-5, the normally open contact 1KM-3 and one end of the electrified coil Q7 are sequentially connected; one end of a first automatic gear of the second change-over switch is connected with the power line L1, the other end of the first automatic gear of the first change-over switch, the normally open contact 1KA-6, the normally open contact 2KM-3 and one end of the electrified coil Q7 are sequentially connected, one end of a second automatic gear of the second change-over switch is connected with the power line L1, and the other end of the second automatic gear of the second change-over switch, the normally open contact 2KA-6, the normally open contact 2KM-3 and one end of the electrified coil Q7 are sequentially connected; one end of a first automatic gear of the third change-over switch is connected with the power line L1, the other end of the first automatic gear of the third change-over switch, the normally open contact 1KA-7, the normally open contact 3KM-3 and one end of the electrified coil Q7 are sequentially connected, one end of a second automatic gear of the third change-over switch is connected with the power line L1, and the other end of the second automatic gear of the third change-over switch, the normally open contact 2KA-7, the normally open contact 3KM-3 and one end of the electrified coil Q7 are sequentially connected.

The water pump control circuit also comprises a self-throwing relay loop, a fault and overflow water level indicating alarm loop and a ring-testing and sound-removing loop, wherein two ends of the self-throwing relay loop, two ends of the fault and overflow water level indicating alarm loop and two ends of the ring-testing and sound-removing loop are respectively connected to the power line L1 and a neutral line N; the self-throwing relay loop comprises a normally open contact KT-1 of a time relay and an electrified coil Q8 of the intermediate relay 4KA, and the normally open contact KT-1 is connected with the electrified coil Q8; the fault and overflow water level indicating loop comprises a normally open contact 1KA-8 of the intermediate relay 1KA, a normally open contact 2KA-8 of the intermediate relay 2KA, a normally open contact 4KA-4 of the intermediate relay 4KA and an indicating lamp 2HY, wherein the normally open contact 1KA-8, the normally open contact 2KA-8 and the normally open contact 4KA-4 are connected with each other, and the normally open contact 1KA-8, the normally open contact 4KA-4 and the indicating lamp 2HY are sequentially connected; the fault and overflow water level alarm loop comprises a normally closed contact 5KA-1 of an intermediate relay 5KA and a sound box HAB, wherein the normally closed contact 5KA-1 is connected with the sound box HAB, and the normally closed contact 5KA-1 is connected with the normally open contact 4 KA-4; this examination bell and remove stereo set return circuit includes this intermediate relay 3 KA's normally open contact 3KA-2, this intermediate relay 5 KA's normally open contact 5KA-2, hand switch SBR, hand switch SBT and this intermediate relay 5 KA's circular telegram coil Q9, this normally open contact 3KA-2, this normally closed contact 5KA-1, normally open contact 5KA-2 and this hand switch SBR interconnect, this hand switch SBT is connected with this pilot lamp 2HY and this normally closed contact 5KA-1 respectively.

The utility model discloses beneficial effect: the circuit structure comprises a first motor, M2 and M3 of three water pumps, wherein the three pumps are not preset as a first working pump, a second working pump or a standby pump, namely any two of the three pumps can automatically work, and the other pump is used as the standby pump. The utility model discloses a main idea is equipped with change over switch on the motor of three water pumps separately, and the change over switch gear has first automatic gear, manual gear, the automatic gear of second and reserve gear. When manual operation is selected, the three water pumps can be directly controlled by manual start and stop button switches respectively, and are not interlocked with each other and can be controlled respectively; when the automatic water pump needs to be operated automatically, the change-over switches of the three water pumps need to respectively correspond to a first automatic gear, a second automatic gear and a standby gear. One or two water pumps are automatically started corresponding to the water quantity through liquid level control (such as a floating ball or other liquid level relays and the like), and when the water level is exceeded, the third standby pump is automatically started. If a fault occurs in two water pumps which work automatically at ordinary times, the third standby water pump also starts automatically and sends out an alarm signal. The control circuit is simple and easy to operate, and can efficiently control the starting and stopping of the three water pumps.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention.

Fig. 2 is a schematic diagram of the main control loop circuit of the present invention.

Fig. 3 is a schematic diagram of a first motor driving circuit according to the present invention.

Fig. 4 is a schematic diagram of a second motor driving circuit according to the present invention.

Fig. 5 is a schematic diagram of a third motor driving circuit according to the present invention.

Fig. 6 is a schematic circuit diagram of the liquid level indicating circuit of the present invention.

Fig. 7 is a partial circuit schematic diagram of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The following disclosure provides many different embodiments or examples for implementing different systems of the invention. In order to simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or reference letters in the various examples, which have been repeated for purposes of simplicity and clarity and do not in themselves dictate a relationship between the various embodiments and/or arrangements discussed. In addition, the present disclosure provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Referring to fig. 1 to 7, the present invention provides a water pump control circuit for solving the above technical problems, which includes a first motor M1, a second motor M2, a third motor M3, a control power supply, a main control loop, a first motor driving loop, a second motor driving loop, a third motor driving loop, and a liquid level indicating loop, the main control loop is connected with the control power supply, the first motor driving loop is connected with the first motor M1, the second motor driving circuit is connected with the second motor M2, the third motor driving circuit is connected with the third motor M3, the liquid level indicating loop, the first motor driving loop, the second motor driving loop and the third motor driving loop are respectively connected with the main control loop for obtaining a circuit power supply, the first motor driving circuit, the second motor driving circuit and the third motor driving circuit are respectively connected with the liquid level indicating circuit; further comprising a first change-over switch 1SAC, a second change-over switch 2SAC and a third change-over switch 3SAC, the first change-over switch 1SAC, the second change-over switch 2SAC and the third change-over switch 3SAC are all provided with a first automatic gear, a second automatic gear, a manual gear and a standby gear, one end of a gear contact on the first change-over switch 1SAC is connected with the main control loop, the other end of the gear contact on the first change-over switch 1SAC is connected with the first motor driving loop, one end of a gear contact on the second change-over switch 2SAC is connected with the main control loop, the other end of the gear contact on the second change-over switch 2SAC is connected with the second motor driving loop, one end of a gear contact on the third change-over switch 3SAC is connected with the main control loop, and the other end of the gear contact on the third change-over switch 3SAC is connected with the third motor driving loop; the liquid level indicating circuit is used for automatically switching on any two circuits in the first motor driving circuit, the second motor driving circuit and the third motor driving circuit after obtaining a preset water level signal so as to drive any two motors in the first motor M1, the second motor M2 and the third motor M3 to work.

In this embodiment, as shown in fig. 2, the control power source is a three-phase ac power source, the main control loop includes a main switch 0QF, a circuit control switch 1QF, a circuit control switch 2QF, a circuit control switch 3QF, an ac contactor 1KM, an ac contactor 2KM, an ac contactor 3KM, a thermal relay 1KH, and a thermal relay 2KH, the circuit control switch 1QF, the circuit control switch 2QF, and the circuit control switch 3QF are respectively connected to the control power source and the main switch 0QF, the main contact of the circuit control switch 1QF, the normally open contact 1KM-1 (not shown in the figure) of the ac contactor 1KM, the thermal relay 1KH, and the first motor M1 are sequentially connected, the main contact of the circuit control switch 2QF, the normally open contact 2KM-1 (not shown in the figure) of the ac contactor 2KM, the thermal relay 2KH, and the second motor M2 are sequentially connected, the main contact of the circuit control switch 3QF, the normally open contact 3KM-1 (not shown in the figure) of the ac contactor 3KM, the thermal relay 3KH and the third motor M3 are connected in sequence, a phase a in the three-phase wiring port on the main switch 0QF leads out a power line L1, a phase a in the three-phase wiring port on the circuit control switch 1QF leads out a power line L11, a phase a in the three-phase wiring port on the circuit control switch 2QF leads out a power line L21, and a phase a in the three-phase wiring port on the circuit control switch 2QF leads out a power line L31.

In this embodiment, as shown in fig. 3, the first motor driving circuit includes a manual switch 1SS, a manual switch 1SF, an energizing coil Q1 of an ac contactor 1KM, a normally closed contact 1KH-1 of a thermal relay 1KH, a normally open contact 1KA-1 of an intermediate relay 1KA, a normally open contact 2KA-1 of an intermediate relay 2KA, a normally open contact 4KA-1 of an intermediate relay 4KA, and a normally open contact 1KM-2 of an ac contactor 1KM, a fuse FU1 is connected to the power line L11, a first automatic gear end, a second automatic gear end, a manual gear end, and a standby gear end of the first transfer switch 1SAC are connected to the fuse FU1, and the other manual gear end of the first transfer switch 1, the manual switch 1SS, the manual switch 1SF, the energizing coil Q1, the normally closed contact 1KH-1, and a neutral line N are connected in sequence, the normally open contact 1KA-1, the normally open contact 2KA-1, the normally open contact 4KA-1 and the electrified coil Q1 are connected with each other, the normally open contact 1KM-2 is connected with the electrified coil Q1, the normally open contact 1KA-1 is connected with the other end of the first automatic gear of the first change-over switch 1SAC, the normally open contact 2KA-1 is connected with the other end of the second automatic gear of the first change-over switch 1SAC, and the normally open contact 4KA-1 is connected with the other end of the standby gear of the first change-over switch 1 SAC.

In this embodiment, as shown in fig. 4, the second motor driving circuit includes a manual switch 2SS, a manual switch 2SF, an energizing coil Q2 of an ac contactor 2KM, a normally closed contact 2KH-1 of a thermal relay 2KH, a normally open contact 1KA-2 of an intermediate relay 1KA, a normally open contact 2KA-2 of an intermediate relay 2KA, a normally open contact 4KA-2 of an intermediate relay 4KA, and a normally open contact 2KM-2 of an ac contactor 2KM, a fuse FU2 is connected to the power line L21, a first automatic gear end, a second automatic gear end, a manual gear end, and a standby gear end of the second transfer switch 2SAC are connected to the fuse FU2, and the other manual gear end of the second transfer switch 2SAC, the manual switch 2SS, the manual switch 2SF, the energizing coil Q2, the normally closed contact 2KH-1, and a neutral line N are connected in sequence, the normally open contact 1KA-2, the normally open contact 2KA-2, the normally open contact 4KA-2 and the electrified coil Q2 are connected with each other, the normally open contact 2KM-2 is connected with the electrified coil Q2, the normally open contact 1KA-2 is connected with the other end of the first automatic gear of the second change-over switch 2SAC, the normally open contact 2KA-2 is connected with the other end of the second automatic gear of the second change-over switch 2SAC, and the normally open contact 4KA-2 is connected with the other end of the standby gear of the second change-over switch 2 SAC.

In this embodiment, as shown in fig. 5, the third motor driving circuit includes a manual switch 3SS, a manual switch 3SF, an energizing coil Q3 of an ac contactor 3KM, a normally closed contact 3KH-1 of a thermal relay 3KH, a normally open contact 1KA-3 of an intermediate relay 1KA, a normally open contact 2KA-3 of an intermediate relay 2KA, a normally open contact 4KA-3 of an intermediate relay 4KA, and a normally open contact 3KM-2 of an ac contactor 3KM, a fuse FU3 is connected to the power line L31, a first automatic gear end, a second automatic gear end, a manual gear end, and a standby gear end of the third transfer switch 3SAC are connected to the fuse FU3, and the other manual gear end of the third transfer switch 3SAC, the manual switch 3SS, the manual switch 3SF, the energizing coil Q3, the normally closed contact 3KH-1, and a neutral line N are connected in sequence, the normally open contact 1KA-3, the normally open contact 2KA-3, the normally open contact 4KA-3 and the electrified coil Q3 are connected with each other, the normally open contact 3KM-2 is connected with the electrified coil Q3, the normally open contact 1KA-3 is connected with the other end of the first automatic gear of the third change-over switch 3SAC, the normally open contact 2KA-3 is connected with the other end of the second automatic gear of the third change-over switch 3SAC, and the normally open contact 4KA-3 is connected with the other end of the standby gear of the third change-over switch 3 SAC.

In this embodiment, as shown in fig. 6, the liquid level indicating circuit includes a liquid level indicating switch 4SL, a liquid level indicating switch 1SL, a liquid level indicating switch 2SL and a liquid level indicating switch 3SL, one end of the liquid level indicating switch 4SL is connected to the live wire L1, the other end of the liquid level indicating switch 4SL is respectively connected to one end of the liquid level indicating switch 1SL, one end of the liquid level indicating switch 2SL, one end of the liquid level indicating switch 3SL, one end of the normally open contact 1KA-4 of the intermediate relay 1KA, one end of the normally open contact 2KA-4 of the intermediate relay 2KA and one end of the normally open contact 3KA-1 of the intermediate relay 3KA, one end of the liquid level indicating switch 1SL is connected to one end of a power-on coil Q4 of the intermediate relay 1KA, the other end of the coil Q4 is connected to the center line N, the other end of the normally open contact 1KA-4 is connected, one end of the liquid level indicating switch 2SL is connected with one end of a powered coil Q5 of the intermediate relay 2KA, the other end of the powered coil Q5 is connected with the central line N, the other end of the normally open contact 2KA-4 is connected with the powered coil Q5, one end of the liquid level indicating switch 3SL is connected with one end of a powered coil Q6 of the intermediate relay 3KA, the other end of the powered coil Q6 is connected with the central line N, and the other end of the normally open contact 3KA-1 is connected with the powered coil Q6.

In this embodiment, as shown in fig. 7, the motor fault indication circuit further includes a standby delay loop, two ends of the standby delay loop are respectively connected to the power line L1 and the neutral line N, and the motor fault indication circuit includes a normally open contact 1KA-5 of the intermediate relay 1KA, a normally open contact 2KA-5 of the intermediate relay 2KA, a normally open contact 1KA-6 of the intermediate relay 1KA, a normally open contact 2KA-6 of the intermediate relay 2KA, a normally open contact 1KA-7 of the intermediate relay 1KA, a normally open contact 2KA-7 of the intermediate relay 2KA, a normally open contact 1KM-3 of the ac contactor 1KM, a normally open contact 2KM-3 of the ac contactor 2KM, a normally open contact 3KM-3 of the ac contactor 3KM, and a coil Q7 of the time relay KT; one end of a first automatic gear of the first change-over switch 1SAC is connected with the power line L1, the other end of the first automatic gear of the first change-over switch 1SAC, a normally open contact 1KA-5, a normally open contact 1KM-3 and one end of an electrified coil Q7 are sequentially connected, the other end of the electrified coil Q7 is connected with the neutral line N, one end of a second automatic gear of the first change-over switch 1SAC is connected with the power line L1, and the other end of a second automatic gear of the first change-over switch 1SAC, a normally open contact 2KA-5, a normally open contact 1KM-3 and one end of an electrified coil Q7 are sequentially connected; one end of a first automatic gear of the second change-over switch 2SAC is connected with the power line L1, the other end of the first automatic gear of the first change-over switch 1SAC, the normally open contact 1KA-6, the normally open contact 2KM-3 and one end of the electrified coil Q7 are sequentially connected, one end of a second automatic gear of the second change-over switch 2SAC is connected with the power line L1, and the other end of the second automatic gear of the second change-over switch 2SAC, the normally open contact 2KA-6, the normally open contact 2KM-3 and one end of the electrified coil Q7 are sequentially connected; one end of a first automatic gear of the third change-over switch 3SAC is connected with the power line L1, the other end of the first automatic gear of the third change-over switch 3SAC, the normally open contact 1KA-7, the normally open contact 3KM-3 and one end of the electrified coil Q7 are sequentially connected, one end of a second automatic gear of the third change-over switch 3SAC is connected with the power line L1, and the other end of the second automatic gear of the third change-over switch 3SAC, the normally open contact 2KA-7, the normally open contact 3KM-3 and one end of the electrified coil Q7 are sequentially connected.

In this embodiment, the system further comprises a self-throwing relay loop, a fault and overflow water level indicating alarm loop and a test bell and sound removing loop, wherein two ends of the self-throwing relay loop, two ends of the fault and overflow water level indicating alarm loop and two ends of the test bell and sound removing loop are respectively connected to the power line L1 and a neutral line N; the self-throwing relay loop comprises a normally open contact KT-1 of a time relay and an electrified coil Q8 of the intermediate relay 4KA, and the normally open contact KT-1 is connected with the electrified coil Q8; the fault and overflow water level indicating loop comprises a normally open contact 1KA-8 of the intermediate relay 1KA, a normally open contact 2KA-8 of the intermediate relay 2KA, a normally open contact 4KA-4 of the intermediate relay 4KA and an indicating lamp 2HY, wherein the normally open contact 1KA-8, the normally open contact 2KA-8 and the normally open contact 4KA-4 are connected with each other, and the normally open contact 1KA-8, the normally open contact 4KA-4 and the indicating lamp 2HY are sequentially connected; the fault and overflow water level alarm loop comprises a normally closed contact 5KA-1 of an intermediate relay 5KA and a sound box HAB, wherein the normally closed contact 5KA-1 is connected with the sound box HAB, and the normally closed contact 5KA-1 is connected with the normally open contact 4 KA-4; this examination bell and remove stereo set return circuit includes this intermediate relay 3 KA's normally open contact 3KA-2, this intermediate relay 5 KA's normally open contact 5KA-2, hand switch SBR, hand switch SBT and this intermediate relay 5 KA's circular telegram coil Q9, this normally open contact 3KA-2, this normally closed contact 5KA-1, normally open contact 5KA-2 and this hand switch SBR interconnect, this hand switch SBT is connected with this pilot lamp 2HY and this normally closed contact 5KA-1 respectively.

The working principle of the circuit structure is as follows: the circuit structure comprises three first motors M1, M2 and M3 of water pumps, wherein the three pumps are not preset as a first working pump, a second working pump or a standby pump, namely any two of the three pumps can automatically work, and the other pump is used as the standby pump. The utility model discloses a main idea is equipped with change over switch on the motor of three water pumps separately, and the change over switch gear has first automatic gear, manual gear, the automatic gear of second and reserve gear. When manual operation is selected, the three water pumps can be directly controlled through the manual switches respectively, and are not interlocked with each other and can be controlled respectively; when the automatic water pump needs to be operated automatically, the change-over switches of the three water pumps need to respectively correspond to a first automatic gear, a second automatic gear and a standby gear. One or two water pumps are automatically started corresponding to the water quantity through liquid level control (such as a floating ball or other liquid level relays and the like), and when the water level is exceeded, the third standby pump is automatically started. If a fault occurs in two water pumps which work automatically at ordinary times, the third standby water pump also starts automatically and sends out an alarm signal.

The working method of the circuit structure comprises the following steps: during the in-service use, when the manual gear on the three change over switches all switches on, the start-up of three motor all relies on the manual switch control among each motor drive circuit, but three motor independent control switch, this paper is no longer repeated. Further, for example, when the first automatic shift position of the first switch 1SAC is turned on, the normally open contact 1KA-1 is closed to start the first electric motor M1. When the second automatic gear of the second switch 2SAC is switched on, the normally open contact 2KA-2 is closed, so that the second motor M2 can be started. When the standby gear of the third changeover switch 3SAC is turned on, the normally-open contact 4KA-3 is closed to start the third motor M3. The liquid level indicating loop comprises a liquid level indicating switch 4SL, a liquid level indicating switch 1SL, a liquid level indicating switch 2SL and a liquid level indicating switch 3SL, and each indicating switch can be a floating ball or other liquid level relays. When the liquid level indicating switch 4SL detects a preset water level, the liquid level indicating switch can be automatically turned off to stop the motors. When the liquid level indicating switch 1SL detects a preset water level II, a liquid level electric signal is given, so that the energizing coil Q4 is switched on, and meanwhile, the normally open contact 1KA-1, the normally open contact 1KA-4, the normally open contact 1KA-5, the normally open contact 1KA-6, the normally open contact 1KA-7 and the normally open contact 1KA-8 are all closed, so that the first motor driving loop motor is switched on, and the first motor M1 is started. Similarly, the starting method of the second motor M2 is the same as that of the first motor M1, namely when the liquid level indicating switch 2SL detects a preset water level three, a liquid level electric signal is given, so that the energizing coil Q5 is switched on, and meanwhile, the normally open contact 2KA-4, the normally open contact 2KA-2, the normally open contact 2KA-5, the normally open contact 2KA-6, the normally open contact 2KA-7 and the normally open contact 2KA-8 are all closed, so that the second motor driving loop motor is switched on, and the second motor M2 is started.

Similarly, if the first automatic gear or the second automatic gear of the third transfer switch 3SAC is switched on, the energizing coil Q6 is energized by the liquid level electrical signal, so that the normally open contact 3KA-1 and the normally open contact 1KA-3 or the normally open contact 2KA-3 are closed, the third motor driving circuit motor is switched on, and the third motor M3 is started. However, the starting of the third motor M3 which is numbered as the backup pump has particularity, specifically, in practical application, when a liquid level electric signal in a liquid level indicating loop causes the backup pump to be started, it indicates that the water amount in a pool or other water carrying equipment where the three pumps work has reached a loading limit, and the water overflows, at this time, the normally open contact 3KA-2 is closed, the indicator light 2HY lights, and the sound HAB gives an alarm, and meanwhile, when a backup gear on any one of the transfer switches is switched on, the normally open contact 4KA-1, the normally open contact 4KA-2, and the normally open contact 4KA-3 connected with the backup gear are all closed, and the backup third motor M3 is started. An operator closes the manual switch SBR, the normally open contact 5KA-2 is closed, and the normally closed contact 5KA-1 is opened, so that the alarm sound is relieved, but the indicator light 2HY is still in a normally-on state. When the liquid level indicating switch 4SL is changed from the normally closed state to the normally open state, the energizing coil Q6 loses power, the normally open contact 3KA-1 is restored from the normally closed state to the normally open state, the indicating lamp 2HY is not lightened, and therefore the fact that faults caused by overhigh water level in the circuit are relieved is proved. The manual switch SBT is a test button for checking whether the indicator lamp 2HY and the sound HAB have a failure when the circuit has no failure.

In this embodiment, the using method (for example) of the standby delay loop is as follows: when the first automatic gear of the first change-over switch 1SAC in the first drive circuit is turned on, correspondingly, the first automatic gear of the first change-over switch 1SAC in the standby delay circuit is also turned on, that is, the first automatic gear of the first change-over switch 1SAC in the first drive circuit and the first automatic gear of the first change-over switch 1SAC in the standby delay circuit are the number of change-over contacts of one, similarly, when the second automatic gear of the second change-over switch 2SAC in the second drive circuit is turned on, correspondingly, the second automatic gear of the second change-over switch 2SAC in the standby delay circuit is also turned on, and when the standby gear of the third change-over switch 3SAC in the third drive circuit is turned on, correspondingly, the standby gear of the third change-over switch 3SAC in the standby delay circuit is also turned on. If the normally open contact 1KA-4 is closed when the energizing coil Q4 is energized, the normally open contact 1KA-5 and the normally open contact 1KA-8 are also closed, and meanwhile, according to the above, the normally open contact 1KA-1 is closed, the energizing coil Q1 is energized, and the normally closed contact 1KM-3 is opened. Similarly, the normally open contact 2KA-2 is closed, the energizing coil Q2 is energized, and the normally closed contact 2KM-3 is opened. As shown, the third switch 3SAC in the standby delay loop does not have a switching contact of the standby gear, and the circuits at signals 25 and 29 are not switched on. The standby time delay circuit in the circuit structure is used for detecting whether the first motor driving circuit and the second motor driving circuit have faults (only for example), specifically, if the normally closed contact 1KM-3 or the normally closed contact 2KM-3 is not disconnected due to the circuit fault, an electric signal is transmitted to the energizing coil Q7, when the time relay KT and the energizing coil Q7 are used for presetting and controlling a time period, which can be more than ten seconds or tens of seconds, when the preset time is exceeded, the electric signal is transmitted in the circuit of any one motor driving circuit or any one motor (or water pump) due to the fault, but the corresponding motor is still not started, the normally open contact KT-1 is closed, the energizing coil Q8 is switched on, and the normally open contact 4KA-4 is closed (the normally open contact 1KA-8 and the normally open contact 2KA-8 are still closed), the indicator light 2HY and the sound HAB are also connected, the standby pump is required to be automatically switched on, a user is informed to overhaul, and after the alarm is relieved by closing the manual switch SBR, the user carries out troubleshooting on the circuit.

Normally open contact 1KM-2, normally open contact 2KM-2 and normally open contact 3KM-2 are closed when each motor drive loop normally works, and an indicator lamp (the position is not shown in the text, please refer to each figure) is connected behind each switch, and the normally open contacts only play the role of indicating the normal work of the circuit, and are not described again herein.

In summary, although the present invention has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so that the scope of the present invention shall be defined by the appended claims.

Claims (9)

1. A water pump control circuit comprises a first motor, a second motor and a third motor, and is characterized by further comprising a control power supply, a main control loop, a first motor driving loop, a second motor driving loop, a third motor driving loop and a liquid level indicating loop, wherein the main control loop is connected with the control power supply, the first motor driving loop is connected with the first motor, the second motor driving loop is connected with the second motor, the third motor driving loop is connected with the third motor, the liquid level indicating loop, the first motor driving loop, the second motor driving loop and the third motor driving loop are respectively connected with the main control loop to obtain a circuit power supply, and the first motor driving loop, the second motor driving loop and the third motor driving loop are respectively connected with the liquid level indicating loop; the motor driving circuit also comprises a first change-over switch, a second change-over switch and a third change-over switch, wherein one end of a gear contact on the first change-over switch is connected with the main control loop, the other end of the gear contact on the first change-over switch is connected with the first motor driving loop, one end of a gear contact on the second change-over switch is connected with the main control loop, the other end of the gear contact on the second change-over switch is connected with the second motor driving loop, one end of a gear contact on the third change-over switch is connected with the main control loop, and the other end of the gear contact on the third change-over switch is connected with the third motor driving loop; the liquid level indicating loop is used for enabling any two circuits in the first motor driving loop, the second motor driving loop and the third motor driving loop to be automatically switched on after a preset water level signal is obtained so as to drive any two motors in the first motor, the second motor and the third motor to work.

2. The pump control circuit according to claim 1, wherein the control power source is a three-phase ac power source, the main control circuit comprises a main switch 0QF, a circuit control switch 1QF, a circuit control switch 2QF, a circuit control switch 3QF, an ac contactor 1KM, an ac contactor 2KM, an ac contactor 3KM, a thermal relay 1KH, and a thermal relay 2KH, the circuit control switch 1QF, the circuit control switch 2QF, and the circuit control switch 3QF are respectively connected to the control power source and the main switch 0QF, the main contact of the circuit control switch 1QF, the normally open contact 1KM-1 of the ac contactor 1KM, the thermal relay 1KH, and the first motor are sequentially connected, the main contact of the circuit control switch 2QF, the normally open contact 2KM-1 of the ac contactor 2KM, the thermal relay 2KH, and the second motor are sequentially connected, the main contact of the circuit control switch 3QF, the normally open contact 3KM-1 of the alternating current contactor 3KM, the thermal relay 3KH and the third motor are sequentially connected, a power line L1 is led out from A phase in a three-phase wiring port on the main switch 0QF, a power line L11 is led out from A phase in the three-phase wiring port on the circuit control switch 1QF, a power line L21 is led out from A phase in the three-phase wiring port on the circuit control switch 2QF, and a power line L31 is led out from A phase in the three-phase wiring port on the circuit control switch 2 QF.

3. The water pump control circuit of claim 2, wherein the first, second, and third switches are each provided with a first automatic gear, a second automatic gear, a manual gear, and a backup gear.

4. The water pump control circuit according to claim 3, wherein the first motor driving circuit comprises a manual switch 1SS, a manual switch 1SF, an energizing coil Q1 of an AC contactor 1KM, a normally closed contact 1KH-1 of a thermal relay 1KH, a normally open contact 1KA-1 of an intermediate relay 1KA, a normally open contact 2KA-1 of an intermediate relay 2KA, a normally open contact 4KA-1 of an intermediate relay 4KA, and a normally open contact 1KM-2 of an AC contactor 1KM, the power line L11 is connected with a fuse FU1, a first automatic gear end, a second automatic gear end, a manual gear end, and a standby gear end of the first transfer switch are connected with the fuse FU1, and the other manual gear end of the first transfer switch, the manual switch 1SS, the manual switch 1SF, and the energizing coil Q1, The normally closed contact 1KH-1 is connected with a neutral line N in sequence, the normally open contact 1KA-1, the normally open contact 2KA-1, the normally open contact 4KA-1 and the electrified coil Q1 are connected with each other, the normally open contact 1KM-2 is connected with the electrified coil Q1, the normally open contact 1KA-1 is connected with the other end of the first automatic gear of the first change-over switch, the normally open contact 2KA-1 is connected with the other end of the second automatic gear of the first change-over switch, and the normally open contact 4KA-1 is connected with the other end of the standby gear of the first change-over switch.

5. The pump control circuit of claim 4, wherein the second motor driving circuit comprises a manual switch 2SS, a manual switch 2SF, a power coil Q2 of an AC contactor 2KM, a normally closed contact 2KH-1 of a thermal relay 2KH, a normally open contact 1KA-2 of an intermediate relay 1KA, a normally open contact 2KA-2 of an intermediate relay 2KA, a normally open contact 4KA-2 of an intermediate relay 4KA, and a normally open contact 2KM-2 of an AC contactor 2KM, the power line L21 is connected with a fuse FU2, the first automatic gear end, the second automatic gear end, the manual gear end, and the standby gear end of the second transfer switch are connected with the fuse FU2, and the other manual gear end of the second transfer switch, the manual switch 2SS, the manual switch 2SF, and the power coil Q2, The normally closed contact 2KH-1 is connected with a neutral line N in sequence, the normally open contact 1KA-2, the normally open contact 2KA-2, the normally open contact 4KA-2 and the electrified coil Q2 are connected with each other, the normally open contact 2KM-2 is connected with the electrified coil Q2, the normally open contact 1KA-2 is connected with the other end of the first automatic gear of the second change-over switch, the normally open contact 2KA-2 is connected with the other end of the second automatic gear of the second change-over switch, and the normally open contact 4KA-2 is connected with the other end of the standby gear of the second change-over switch.

6. The pump control circuit of claim 5, wherein the third motor driving circuit comprises a manual switch 3SS, a manual switch 3SF, a power coil Q3 of an ac contactor 3KM, a normally closed contact 3KH-1 of a thermal relay 3KH, a normally open contact 1KA-3 of an intermediate relay 1KA, a normally open contact 2KA-3 of an intermediate relay 2KA, a normally open contact 4KA-3 of an intermediate relay 4KA, and a normally open contact 3KM-2 of an ac contactor 3KM, the fuse FU3 is connected to the power line L31, the first automatic gear end, the second automatic gear end, the manual gear end, and the backup gear end of the third switch are connected to the fuse FU3, and the other manual gear end of the third switch, the manual switch 3SS, the manual switch 3SF, and the power coil Q3 of the third switch, The normally closed contact 3KH-1 is connected with a neutral line N in sequence, the normally open contact 1KA-3, the normally open contact 2KA-3, the normally open contact 4KA-3 and the electrified coil Q3 are connected with each other, the normally open contact 3KM-2 is connected with the electrified coil Q3, the normally open contact 1KA-3 is connected with the other end of the first automatic gear of the third change-over switch, the normally open contact 2KA-3 is connected with the other end of the second automatic gear of the third change-over switch, and the normally open contact 4KA-3 is connected with the other end of the standby gear of the third change-over switch.

7. The water pump control circuit according to claim 6, wherein the liquid level indicating circuit comprises a liquid level indicating switch 4SL, a liquid level indicating switch 1SL, a liquid level indicating switch 2SL, and a liquid level indicating switch 3SL, one end of the liquid level indicating switch 4SL is connected to the power line L1, the other end of the liquid level indicating switch 4SL is connected to one end of the liquid level indicating switch 1SL, one end of the liquid level indicating switch 2SL, one end of the liquid level indicating switch 3SL, one end of the normally open contact 1KA-4 of the intermediate relay 1KA, one end of the normally open contact 2KA-4 of the intermediate relay 2KA, and one end of the normally open contact 3KA-1 of the intermediate relay 3KA, one end of the liquid level indicating switch 1SL is connected to one end of an energizing coil Q4 of the intermediate relay 1KA, and the other end of the energizing coil Q4 is connected to the neutral line N, this normally open contact 1KA-4 other end is connected with this circular telegram coil Q4, the one end of this liquid level indication switch 2SL and the circular telegram coil Q5 one end of this auxiliary relay 2KA are connected, this circular telegram coil Q5 other end is connected with this neutral line N, this normally open contact 2KA-4 other end is connected with this circular telegram coil Q5, the one end of this liquid level indication switch 3SL and the circular telegram coil Q6 one end of this auxiliary relay 3KA are connected, this circular telegram coil Q6 other end is connected with this neutral line N, this normally open contact 3KA-1 other end is connected with this circular telegram coil Q6.

8. The water pump control circuit of claim 7, further comprising a backup delay loop, the two ends of the standby time delay loop are respectively connected to the power line L1 and a neutral line N, the motor fault indication loop comprises a normally open contact 1KA-5 of the intermediate relay 1KA, a normally open contact 2KA-5 of the intermediate relay 2KA, a normally open contact 1KA-6 of the intermediate relay 1KA, a normally open contact 2KA-6 of the intermediate relay 2KA, a normally open contact 1KA-7 of the intermediate relay 1KA, a normally open contact 2KA-7 of the intermediate relay 2KA, a normally open contact 1KM-3 of an alternating current contactor 1KM, a normally open contact 2KM-3 of an alternating current contactor 2KM, a normally open contact 3KM-3 of the alternating current contactor 3KM and an energizing coil Q7 of a time relay KT; one end of a first automatic gear of the first change-over switch is connected with the power line L1, the other end of the first automatic gear of the first change-over switch, the normally open contact 1KA-5, the normally open contact 1KM-3 and one end of the electrified coil Q7 are sequentially connected, the other end of the electrified coil Q7 is connected with the neutral line N, one end of a second automatic gear of the first change-over switch is connected with the power line L1, and the other end of the second automatic gear of the first change-over switch, the normally open contact 2KA-5, the normally open contact 1KM-3 and one end of the electrified coil Q7 are sequentially connected; one end of a first automatic gear of the second change-over switch is connected with the power line L1, the other end of the first automatic gear of the first change-over switch, the normally open contact 1KA-6, the normally open contact 2KM-3 and one end of the electrified coil Q7 are sequentially connected, one end of a second automatic gear of the second change-over switch is connected with the power line L1, and the other end of the second automatic gear of the second change-over switch, the normally open contact 2KA-6, the normally open contact 2KM-3 and one end of the electrified coil Q7 are sequentially connected; one end of a first automatic gear of the third change-over switch is connected with the power line L1, the other end of the first automatic gear of the third change-over switch, the normally open contact 1KA-7, the normally open contact 3KM-3 and one end of the electrified coil Q7 are sequentially connected, one end of a second automatic gear of the third change-over switch is connected with the power line L1, and the other end of the second automatic gear of the third change-over switch, the normally open contact 2KA-7, the normally open contact 3KM-3 and one end of the electrified coil Q7 are sequentially connected.

9. The water pump control circuit according to claim 8, further comprising a self-throwing relay circuit, a fault and overflow water level indicating alarm circuit and a test bell and release sound circuit, wherein two ends of the self-throwing relay circuit, two ends of the fault and overflow water level indicating alarm circuit and two ends of the test bell and release sound circuit are respectively connected to the power line L1 and a neutral line N; the self-throwing relay loop comprises a normally open contact KT-1 of a time relay and an electrified coil Q8 of the intermediate relay 4KA, and the normally open contact KT-1 is connected with the electrified coil Q8; the fault and overflow water level indicating loop comprises a normally open contact 1KA-8 of the intermediate relay 1KA, a normally open contact 2KA-8 of the intermediate relay 2KA, a normally open contact 4KA-4 of the intermediate relay 4KA and an indicating lamp 2HY, wherein the normally open contact 1KA-8, the normally open contact 2KA-8 and the normally open contact 4KA-4 are connected with each other, and the normally open contact 1KA-8, the normally open contact 4KA-4 and the indicating lamp 2HY are sequentially connected; the fault and overflow water level alarm loop comprises a normally closed contact 5KA-1 of an intermediate relay 5KA and a sound box HAB, wherein the normally closed contact 5KA-1 is connected with the sound box HAB, and the normally closed contact 5KA-1 is connected with the normally open contact 4 KA-4; this examination bell and remove stereo set return circuit includes this intermediate relay 3 KA's normally open contact 3KA-2, this intermediate relay 5 KA's normally open contact 5KA-2, hand switch SBR, hand switch SBT and this intermediate relay 5 KA's circular telegram coil Q9, this normally open contact 3KA-2, this normally closed contact 5KA-1, normally open contact 5KA-2 and this hand switch SBR interconnect, this hand switch SBT is connected with this pilot lamp 2HY and this normally closed contact 5KA-1 respectively.

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