Under Voltage Protection Relay Circuit Diagram

This is a safety device to overvoltage.

Under voltage protection relay circuit diagram. Over voltage protection circuit using tl431 shunt regulator ic. After that relay rl 2 get energized and the boosted voltage shows up at the n o contact rl 1 b of relay rl 1 but under two conditions relay rl 1 lies in de energized condition. Protection circuits like reverse polarity protection short circuit protection and over under voltage protection are used to protect any electronic appliance or circuit from any sudden mis happening generally fuse or mcb is used for overvoltage protection here in this circuit we will build an overvoltage protection circuit without using fuse. As shown in the circuit diagram a couple of transistor stages are integrated together along with an output relay which is able to perform the function of super safe voltage guard equipment.

The overcurrent relay is used to protect the alternator or generator against overloading and which trip the circuit breaker. Automatic equipment disconnect when the power cross the level of a fixed voltage. This is a shunt regulator diode. As explained above the transistors sense the presence of the dangerous voltage levels respectively and activate.

Second due to initial shunting effect of capacitor c. The maximum limit for input line voltage is 140 v. Another important criteria in overcurrent element is protection against. High voltage low voltage cut off circuit.

Thus the output of operational amplifier n2 goes high and it energizes the relay through. First when the input line voltage is controlled by trim pot vr 1 and is below 170v threshold voltage level. Now let s consider the under voltage condition. Over voltage and under voltage circuit using comparator.

In the normal operating conditions between 160 and 250 v the output of the timer 1 is held low so the transistor 1 is in cutoff state as a result the reset pin of the timer 2 is high which causes to output at pin 3 is high so the transistor 2 conducts and then the relay coil gets energized. As per datasheet tl431a is the three terminal programmable integrated circuit. When the line voltage is below 180 v the voltage at the inverting terminal pin 6 of operational amplifier n2 is less than the voltage at the non inverting terminal 6 v. This circuit protects from high voltage.

Overvoltage protection circuit using timers. Phase failure and under over voltage master control motor circuits protection relay in this video we can see you full introduction these protection of motor with zahra rst 25 master control relay.