Time Mark 295-120 - Capacitor Trip Device (120V)

The Model 295-120 Capacitor Trip Device is used to trip circuit breakers requiring an AC voltage, by using the stored energy in a capacitor. The capacitor is kept at full charge during normal operation by a half-wave silicon rectifier which draws its energy from the power line.

When completely discharged, the Model 295-120 draws approximately 10 amps from the line in the first half cycle, 3 amps in the second half cycle, and 1 amp from the third. The continuous current required to keep the capacitor charged is less than 5 milliamps.

The capacitor holds sufficient charge to trip the breaker for at least 12 seconds after the charging voltage is removed. However, on most fault conditions, some voltage is still present, so the Model 295-120 is designed so that 65% of normal voltage gives sufficient charge to trip the breaker.

A low-energy lamp, connected in parallel with the storage capacitor, gives a visual indication when the voltage charge is 85 volts or more on the 120V version and 170 volts or more on the 240V version.