CN2473792Y - Power phase lost protector for three phase power supply equipment - Google Patents

Abstract

The utility model relates to a power supply phase lacking protector of a three-phase power supply equipment, comprising an ac contactor and two relays. The coil winding of the ac contactor and the coil winding of the second relay are shunted between the two phases of the three-phase power supply line. The coil winding of the first relay is shunted between the third power supply line and one phase of the two phase line. The control contract of the first relay and the control contract of the second relay are shunted at the two ends of the ac contactor starting key-press after being series connected. The power supply phase lacking protector can cut off the three-phase power supply timely and protect the electromechanical equipment when any phase of the three-phase power supply is in the status of circuit opening and phase lacking.

Description

A kind of power supply open phase protector of three phase mains power supply unit

The utility model relates to the power supply open phase protector of three phase mains power supply unit.

At present; electromechanical equipments such as all kinds of alternating current motors and water pump all are the three phase mains power supplies; its protective device is to be connected to A.C. contactor in supply line, and wherein the coil windings of A.C. contactor is connected across in wherein the two-phase supply line, three control contacts are connected in the three-phase power line respectively.Since the coil windings of A.C. contactor just with three-phase power line in two be connected, if the third phase supply line of the wiring circle winding phase shortage that opens circuit not, A.C. contactor is operate as normal still, three control closings of contact, continuation is to the power supply of load phase shortage, as the electromechanical equipment of load, as the electrical appliance of motor or water pump one class, because the power supply phase shortage is very easily burnt out.

The purpose of this utility model provides the power supply open phase protector that can both stop when a kind of three phase supply power supply any opens circuit phase shortage mutually to the three phase mains power supply unit of electrical appliance power supply.

The power supply open phase protector of this three phase mains power supply unit; comprise an A.C. contactor; the coil windings of A.C. contactor; wherein one being connected of one end and three-phase power line; the other end with stop key; starting button series connection back is connected with in the three-phase power line another; three control contacts of A.C. contactor are connected in the three-phase power line respectively; its design feature is also to comprise two relays; the coil windings of first relay; in one end and the two-phase supply line that connects the ac contactor coil winding any one is connected; the other end is connected with third phase supply line; the coil windings two ends of second relay are connected in parallel in the two-phase supply line of the coil windings that connects A.C. contactor, the control contact of first relay and the two ends that are connected in parallel on the starting button after connecting in the control contact of second relay.

The operation principle of the power supply open phase protector of this three phase mains power supply unit is: occur the phase shortage that opens circuit mutually as if any one in the two-phase supply line that connects the ac contactor coil winding, no current passes through in the ac contactor coil winding, three control contacts of A.C. contactor are converted to normally open by attracting state, cut off the three phase supply power supply of electrical appliance, at this moment, no current passes through in the second relay coil winding, it controls not adhesive of contact, disconnects ac contactor coil winding current loop; The phase shortage that opens circuit does not appear if meet the third phase supply line of ac contactor coil winding, no current passes through in first relay coil winding, the control contact of this relay is converted to normally open by attracting state, cut off ac contactor coil winding current loop, no current passes through in the ac contactor coil winding, identical with the principle of first kind of situation, by three three phase supply power supplys of controlling the break of contact electrical appliances of A.C. contactor; If the three phase mains normal power supply, the control contact of first relay that is connected in series and the control contact of second relay are as the self holding contact of A.C. contactor.

From the above mentioned; if in the three-phase power line of the electromechanical equipment of motor, water pump one class by loading onto power supply open phase protector described in the utility model; in the three-phase power line any one phase shortage that opens circuit mutually; can both cut off the three phase supply power supply in time, can not burn out electromechanical equipment because of the phase shortage power supply.

Accompanying drawing shows the circuit structure schematic diagram of the power supply open phase protector embodiment of this three phase mains power supply unit.

In the present embodiment, the power supply open phase protector of three phase mains power supply unit comprises an A.C. contactor, the coil windings KM of A.C. contactor, an end and three-phase power line wherein one mutually A connect, the other end with stop key SB ₁, starting button SB ₂In series connection back and the three-phase power line another B mutually connects, three of A.C. contactor control A phase that contact KM-1, KM-2, KM-3 are connected on three-phase power line successively, B phase, C mutually in, the coil windings KA of first relay ₁, an end links to each other with B, and the other end is connected with C, the coil windings KA of second relay ₂, an end is connected with A, and the other end is connected with B, the control contact KA of first relay ₁The control contact KA of-1 and second relay ₂Be connected in parallel on after-1 series connection and start button SB ₂Two ends, first relay is corresponding with the specifications and models of A.C. contactor with the specifications and models that second relay selected for use.

Among the figure, M is electrical appliance, FU₁、FU ₂And FU₃Be fuse.

Claims (2)

1, a kind of power supply open phase protector of three phase mains power supply unit comprises an A.C. contactor, the coil windings of A.C. contactor (KM), in an end and the three-phase power line wherein one mutually (B) connect, the other end with stop key (SB ₁), starting button (SB ₂) another (A) connection mutually in series connection back and the three-phase power line, three control contacts (KM-1, KM-2, KM-3) of A.C. contactor are connected in the three-phase power line respectively, it is characterized in that also comprising two relays, the coil windings (KA of first relay ₁), any one in an end and the two-phase supply line that connects ac contactor coil winding (KM) (B) mutually connects, and the other end is connected with third phase supply line (C), the coil windings (KA of second relay ₂) two ends are connected in parallel in the two-phase supply line of the coil windings (KM) that connects A.C. contactor the control contact (KA of first relay ₁-1) with the control contact (KA of second relay ₂-1) is connected in parallel on the two ends of starting button (SB2) after the series connection.

2, the power supply open phase protector of three phase mains power supply unit according to claim 1 is characterized in that the specifications and models that first relay and second relay select for use are corresponding with the specifications and models of A.C. contactor.