CN2133935Y

CN2133935Y - Phase interruption protection ac contactor

Info

Publication number: CN2133935Y
Application number: CN 92220138
Authority: CN
Inventors: 唐龙棫
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-08-19
Filing date: 1992-08-19
Publication date: 1993-05-19
Anticipated expiration: 2002-08-19

Abstract

The utility model relates to an AC contactor with open-phase protection function, which is composed of two coils and two groups of AC switches which are connected in series, and the two coils are respectively bridged at the different braches of three-branch switches. The utility model doesn't change the circuit of the existing machine tool and replaces directly the original AC contactor, and the motor can be protected reliably under the situation of open-phase.

Description

Phase interruption protection ac contactor

The utility model relates to the starting drive and the protective device of motor, particularly a kind of A.C. contactor that exchanges contact and open-phase protection function that has concurrently.

Existing A.C. contactor only plays break-make to motor and starts and the o-volt protection effect, does not have the open-phase protection function, therefore, often burns motor because of the circuit phase shortage.The prior motor open phase protector mostly is electronic component and constitutes; this series products must be used existing A.C. contactor just can finish open-phase protection; and also must be equipped with the open phase protector of different size to the motor of different capacity; the price of every open phase protector does not wait from 70 yuan to 700 yuan; therefore, the plant produced cost is higher, again owing to be two kinds of devices; the circuit difference is installed also inconvenient.

The purpose of this utility model is under the prerequisite of not changing existing Machine Tool Electric Appliance circuit, designs a kind ofly to melt the electric motor starting function and the open-phase protection function is the A.C. contactor of one, to replace the A.C. contactor of existing no phase shortage defencive function.

The technical measures that the utility model is taked can achieve the above object, it is by pedestal, two coils and two groups of formations such as interlock normally opened contact, every group of interlock normally opened contact has three pairs, two groups of interlock normally opened contacts are connected in series respectively, form three-way switch corresponding to three phase mains, two coils are connected across respectively on the two contacts branch road inequality in the three-way switch, a coil crossover is in the front end of interlock normally opened contact, its coil voltage is 380 volts or 220 volts, another coil crossover is in the series connection mid point of two groups of interlock normally opened contacts, the voltage of this coil is 380 volts, and when being 380 volts as if last coil voltage, the switching branches of two coils institute cross-over connection does not overlap, if last coil is when being 220 volts, this coil crossover is on the branch road and zero line that have nothing to do with back one coil.

Protection philosophy of the present utility model is an o-volt protection principle of having utilized A.C. contactor; two coils are connected across respectively on the two contacts branch road inequality in the three-way switch; promptly be to be connected across on the three-phase phase sequence inequality; again because of three-way switch contact interlock; so any phase decompression all can not make the contact of interlock normally opened contact; be that motor can not get electric startup, thereby reach open-phase protection motor.

The utility model circuit is in series by two A.C. contactors; so external circuit is not had specific (special) requirements; its outstanding advantage is to need not existing machine tool circuit is made any change, and just this A.C. contactor is displaced existing A.C. contactor can reach the purpose that effective protection motor is not burnt.

If two A.C. contactors of the present utility model are used, can be used for controlling the contrary running of motor.

The utility model is applicable to the electric motor starting and the open-phase protection of any lathe.

Provide embodiment below in conjunction with accompanying drawing.

The Electric Machine Control winding diagram of the existing contactor of Fig. 1

Fig. 2 has the reversible control major loop of motor winding diagram now

Fig. 3 the utility model directly starts, and two coil voltages are 380 volts major loop winding diagram

The major loop winding diagram of Fig. 4 band control loop

Fig. 5 ZC coil voltage is 220 volts, the major loop winding diagram of band control loop

Fig. 6 motor reversible operation major loop winding diagram

Among Fig. 3, interlock normally opened contact ZC ¹With QC ¹Three pairs of contacts are all arranged, and the two is connected in series, and its coil voltage is 380 volts.Coil ZC be connected across corresponding to B mutually with C contact switch branch road mutually on, be connected to interlock normally opened contact ZC ¹Front end, coil QC be connected across corresponding to A mutually with C contact switch branch road mutually on, be connected to ZC ¹With QC ¹The series connection mid point, KH is a knife switch, this example is the connecting line construction that directly starts.

So the difference of Fig. 4 and Fig. 3 is only starting by pressing key control.

Among Fig. 5, the coil voltage of coil ZC is 220 volts, cross-over connection in the irrelevant B of coil QC mutually on contact switch branch road and the zero line.

Fig. 6 is a motor reversible operation major loop winding diagram.It exchanges protector by two phase shortages and is used, and the principle and the previous examples of the wiring position of its coil crossover contact switch branch road and two coils are in full accord.

The utlity model has simple in structurely, with low cost, installation, use, easy to maintenance to the outstanding reliably advantage of motor open-phase protection, as long as two coils are under the intact situation, if this A.C. contactor is not worked, must be phase shortages in the then whole circuit.

Can derive series of products according to design feature of the present utility model and principle.

Claims

1, open-phase protection A.C. contactor, by pedestal, two coil ZC, QC, two groups of interlock normally opened contact ZC ¹, QC ¹Etc. formation, it is characterized in that every group of interlock normally opened contact has three pairs, two groups of interlock normally opened contact ZC ¹With QC ¹Be connected in series respectively, form three-way switch corresponding to three phase mains, two coils are connected across respectively on the two contacts branch road inequality in the three-way switch, and coil ZC is connected to interlock normally opened contact ZC ¹Front end, its coil voltage is 380 volts or 220 volts, coil QC is connected to interlock normally opened contact ZC ¹With QC ¹The series connection mid point, this coil voltage is 380 volts, if the ZC coil voltage is when being 380 volts, coil ZC does not overlap with the branch road of coil QC institute cross-over connection, when being 220 volts as if the ZC coil voltage, this coil crossover is on the branch road and zero line that have nothing to do with the QC coil.