Testing a Circuit Breaker With Extended Rotary Handle

Push-to-Trip Procedure

CAUTION
HAZARD OF NUISANCE TRIPPING Device tests must only be done by qualified electrical personnel. Failure to follow these instructions can result in injury or equipment damage.

When testing the trip mechanism take precautions against:

Disrupting operations
Activating inappropriate alarms
Triggering unwanted actions

For example, tripping the circuit breaker with the push-to-trip button can lead to inappropriate fault indications or corrective actions (such as switching to an alternate power source).

There is no push-to-trip button on the door of a circuit breaker with a front extended rotary handle. To check the trip mechanism, the door must first be opened.

Follow these steps to test the trip mechanism:

Step		Position
1	Switch the circuit breaker to the open O (OFF) position. Open the door.	O (OFF)
2	Turn the circuit breaker from the O (OFF) position to the I (ON) position, using one of the following tools: An open door shaft operator (LV426937). A flat wrench, taking care not to damage the extension shaft or its surface treatment. The extension shaft is a solid square section shaft, 10 x 10 mm (0.39 x 0.39 in). The circuit breaker is ready for the test.	I (ON)
3	Press the push-to-trip button. The circuit breaker trips.	Trip
4	Use a specific tool (refer to step 2) to turn the extension shaft counterclockwise and switch the circuit breaker from the Trip position to the O (OFF) position. The circuit breaker is in the open position.	O (OFF)
5	Close the door.	–