CN2141945Y - Loss-of-phase protector for ac three phase motor - Google Patents

Abstract

The utility model belongs to a loss-of-phase protector for an ac three phase motor, comprising a housing, and a combined type capacitor which is arranged in the housing. The head end of the combined type capacitor is connected with the power supply, a communal end N1 is connected with a terminal L1 of a relay winding and used as a signal sensor of phase interruption, and the other terminal L2 of the relay winding is connected with a communal zero wire to make the two normally closed contact outputs connected with a control loop of contactor or air switch. The utility model has the advantages of small size, light weight, convenient installation, long service life and good protective performance, and is suitable for the open-phase protection of motor whose power is under 17KW.

Description

Loss-of-phase protector for ac three phase motor

The utility model relates to a kind of open phase protector of motor, is a kind of overvoltage protection of motor specifically.

At present, because 60～80% of the motor total losses amount that accounts for that three-phase alternating-current motor in use burns because of phase shortage has become a great problem that users influence production.

Make it the three-phase alternating-current motor phase-lacking protective device of domestic market mass selling and use, be used for heavy-duty motor more and be principal mode with the current mode.Its structure adopts big electronic devices and components such as monitoring, warning.Because therefore electronic devices and components in use chance of failure, make this class protector faults itself rate height in the practice process than higher, price comparison is expensive in addition, and production technology is more complicated also.

The purpose of this utility model provides a kind of improved three phase alternating current motor phase failure protector, touches the action with actuator so as to the sudden change that short of electricity is pressed, thereby the defective that can protect the motor phase shortage to damage preferably.

For achieving the above object; the utility model is realized by following measure: have the head end that is arranged on the combined capacitor in the housing and connect power supply; and common port N1 linked to each other with a termination L1 of relay winding can be used as motor default phase signal transducer; another termination L2 that is used for relay winding zero line N together links to each other, and makes the output of two normally closed contacts on the relay and the control loop of A.C. contactor or air switch connect and compose open phase protection.Because utilize neutral point N1 to go up forming a potential state is zero voltage substantially, when any phase shortage of three phase mains, the neutral point N1 and the electric current between zero line that connect capacitor are raise, make the automatic tripping of normally closed contact.

The utility model has the superpotential version of employing compared to existing technology: simple in structure, volume is little, cost is low, and is easy to install and use.Can unfailing performance preferably be arranged for the following motor open-phase protection of 17KW.

The drawing explanation of accompanying drawing:

Fig. 1 is the topology view of this device.

Fig. 2 is a schematic circuit.

Show the structure of three phase alternating current motor phase failure protector by Fig. 1, adopt in the housing (1) of ABS plastic compacting and be provided with combined capacitor (4) and relay (2).And with adding of making of F-6101 epoxy resin, diluent, curing agent and quartz sand material (3) is canned goes in the housing (1), make it each parts and housing (1) and be consolidated into one, play a protective role.Waterproof, moistureproof, avoid damaging because of the back machine vibration is installed, strengthen the reliability of work.On one side of housing (1) outer end, 6 binding posts (5) are housed, are blind hole between the connecting hole that respectively is connected conductor wire end in each binding post (5) and the housing (1), influence electric conductivity when adding material (3) to prevent to pack into by resin penetration.

See Fig. 2 schematic circuit of this protector as can be known; when being connected on the 380V three phase mains on 1,2,3, No. 4 terminals of protector; the three-phase voltage of power supply is added on 1,2, No. 3 terminals of input of the signal transducer that is made of C1, C2, C3 combined capacitor, and forming a potential state on the neutral point N1 of C1, C2, C3 is that zero voltage reference points is zero line or ground wire substantially.When three-phase mains voltage lacks a phase time, to form a potential jump (rising) between the neutral point N1 of its C1, C2, C3 and zero line N, owing to when between neutral point N1 and zero line N, being connected an electromagnetic relay J two-terminal L1, L2, make the voltage of deciding the sudden change rising be enough to promote coil and the mechanism action of jumbo electromagnetic relay J.The normally closed contact of electromagnetic relay J (5,6) trips when exporting in order to the automatic switch phase shortage, plays a protective role.

Claims (3)

1, three phase alternating current motor phase failure protector; comprise that independent capacitance device, relay, connection lead, housing and binding post constitute; it is characterized in that combined capacitor (4) head end that is arranged in the housing (1) connects power supply; common port N1 links to each other as phase failure signal transducer with a terminal L1 of relay (2) winding; the another terminal L2 of relay (2) winding zero line N together links to each other, and two normally closed contact outputs on the relay (2) are connected with contactor or air switch control loop.

2,, it is characterized in that between the connecting hole of binding post (5) and lead be blind hole by the described three phase alternating current motor phase failure protector of claim 1.

3, by the described three phase alternating current motor phase failure protector of claim 1, it is characterized in that the material (3) that adds that its housing (1) inside and parts are filled to be made by F-6101 epoxy resin, diluent, curing agent, quartz sand is consolidated into one.

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