CN2185941Y

CN2185941Y - Under voltage open--phase protector for A.C. motor

Info

Publication number: CN2185941Y
Application number: CN 94226240
Authority: CN
Inventors: 黄楹仙
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-08
Filing date: 1994-02-08
Publication date: 1994-12-21
Anticipated expiration: 2004-02-08

Abstract

The utility model arranges a protective device which is arranged at the front part of an alternate current contactor for controlling the operation of a motor and which is composed of three relays. The leading-in wires of the relays are respectively connected with a three phase power cord and the outgoing wires are connected with a ground wire. The protective contact heads of the three relays are connected in series in the wire bag electric loop of the alternate current contactor. When phase interruption or excess voltage situations happen to a power supply, the alternate current contactor can be switched off to quickly realize the stop of the motor. Thereby, the motor can not be burnt caused by phase interruption or excess voltage.

Description

Under voltage open--phase protector for A.C. motor

The utility model relates to a kind of undervoltage open-phase protection device of alternating current motor.

In the prior art; the overload protection arrangement of alternating current motor can not protect motor to avoid single phasing fully; and single phasing is the formidable enemy of motor work; account for more than 50% of motor windings repairing amount because of single phasing causes the repairing amount of motor scaling loss according to statistics, how single-phase motor running is effectively protected is a difficult problem that needs to be resolved hurrily in this technical field always.

The novel purpose of this usefulness is to provide a kind of and can effectively protects the alternating current motor single phasing, specifically is realize the alternating current motor undervoltage open-phase protection device that under-voltage open-phase running implementation is protected to motor by the A.C. contactor that control is connected with motor.

The technical solution of the utility model is that three control relays are installed in the protector housing; be characterized in the inlet wire of relay is linked to each other with power firestreak; the outlet of relay links to each other with ground wire, and the protection contact series connection back of relay links to each other with the A.C. contactor line bag inlet wire of control motor.

Press such scheme, as circuit " phase failure " or " under-voltage " phenomenon occur, magnetic is taken off in the outage of the relay of this protector, and then its protection contact disconnects, and A.C. contactor line bag is because of its contact tripping of dead electricity, thereby motor is quit work.Avoided present motor only by A.C. contactor protection, and insensitive or take place because of the A.C. contactor action because of its line wraps in the accident that still keeps the connection situation to cause the motor winding to burn under the power supply phase failure undervoltage condition.The utility model can be used with all kinds of A.C. contactors, and after the under-voltage fault of the phase failure was got rid of, its contact automatically reset, and makes motor recover operate as normal automatically.This apparatus structure is simple, and fault is few, easy to maintenance, highly sensitive, is not subjected to the anti-fluid capacitance quantitative limitation of contact, and the power consumptive province can be protected motor normally to move effectively, thereby save spending in a large number.Economic results in society are relatively good.

Fig. 1 is the utility model overall structure schematic diagram.Fig. 2 is the utility model electrical wiring schematic diagram.

Below in conjunction with accompanying drawing the utility model most preferred embodiment further is described: relay (1) is fixed in the protector housing (2), and protector housing can be made of transparent material.The inlet wire of three relays is connected with three phase mains live wire A, B, C respectively, links to each other with ground wire N after the parallel connection of three relay leading-out terminals.The protection contact J of three relays in the body shell ₁, J ₂, J ₃The series connection back links to each other with A.C. contactor line bag (3) inlet wire of control motor, and line contracts out line end and links to each other with live wire C with starting switch K series connection back.Connecting by the binding post (4) that is arranged on the protector housing of relay into and out of line.

When the power supply three-phase alternating current just often, three groups of contacts of relay are connected, and make the A.C. contactor adhesive, motor normally moves.If have the phase failure or under-voltage situation to occur in the three-phase electricity, the relay contact tripping, A.C. contactor disconnects because of its line bag dead electricity, and motor then stops operating immediately, has promptly reached the purpose of protection motor.

Claims

1, a kind of alternating current motor undervoltage open-phase protection device comprises relay (1), it is characterized in that the inlet wire of relay links to each other with power firestreak, and outlet links to each other with ground wire, the protection contact J of relay ₁, J ₂, J ₃The series connection back links to each other with A.C. contactor line bag (3) inlet wire of control motor.

2, protector according to claim 1 is characterized in that relay divides three settings, and is fixed in the protector housing (2), and it connects by the binding post (4) that is arranged on the housing into and out of line.