Relay protection circuit


Posted on Nov 10, 2015

Operating power protection devices, there is a DC power supply operating power and AC operation into two categories.


Relay protection circuit
Click here to download the full size of the above Circuit.

Since the AC operating power with less investment, operation and maintenance is simple and convenient and reliable secondary circuit, so it is widely used in small factories. (1) Direct-action protection circuit uses off circuit breaker manually operated mechanism within the overcurrent release (trip coil) YR as a direct-acting overcurrent relay , a relay connected into a two-phase or two-phase two-relay device type. During normal operation, the current YR by far less than the operating current, and therefore no action. In a second phase short circuit when the circuit, YR movements to trip the circuit breaker QF, this mode of operation is simple by economic, but the protection of low sensitivity, in fact seldom used, as shown in FIG. (2) to shunt trip protection circuit shown in Figure b. Normal operation, the current relay KA normally closed contact will short-circuit trip coil YR stream. YR no current through the circuit breaker QF is not so trips. When the primary circuit phase short circuit, the current relay KA action, the normally closed contacts disconnect, short-circuit trip coil YR partial stream branch is removed, the so-called "de-streaming", so that the current transformer secondary current all through YR, QF causing the circuit breaker tripped, the so-called "de-shunt trip." Wiring this mode of operation is relatively simple, reliable and sensitive, but requires current relay KA breaking contacts can force big enough. GL15,16 on the market and other types of GL25,26 current relay, which contacts a large capacity, short break current unitary division of 150A, fully able to meet short circuit "to shunt trip" requirements. Therefore, this mode of operation to shunt trip power supply system in the factory now applied quite widely.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Integrator-ramp-generator-with-initial-condition-reset
Regulated Charge Pump
siren alarm circuit diagram usng lm358
flight computer
metal detector circuit
4 20ma current loop tester
Electronics and Home Automation
MiniDCC Project
A BIPOLAR REGENERATIVE RECEIVER
Using TX05C new infrared burglar alarm circuit diagram



Top