Undervoltage release is long-term work, when the power supply voltage drop in the operating voltage range when the release is released, and directly led to the tripping axle rotation, cut off the breaker.
Undervoltage release Instantaneous tripping points and tripping delay two species. Which reached the undervoltage delay trip there two ways kinds: one is the electronic trip unit (see Figure 6-81); the other one is the resistive capacitive delay release, the line shown in Figure 6-84 FIG. FIG, Q is undervoltage release coil. Adjustment capacitor C and a resistor Ri, the parameter value of R2, can change the delay time.