Opening, Closing, Resetting, and Testing the Circuit Breaker

Opening and Closing with the Toggle Handle

Task	Action
Open the circuit breaker	Push the toggle handle from the I (ON) position to the O (OFF) position.
Close the circuit breaker	Push the toggle handle from the O (OFF) position to the I (ON) position

Resetting with the Toggle Handle After a Trip

When the circuit breaker trips, the toggle handle moves from the I (ON) position to the (Trip) position.

WARNING
HAZARD OF CLOSING ON ELECTRICAL FAULT Do not close the circuit breaker again without first inspecting and, if necessary, repairing the downstream electrical equipment. Failure to follow these instructions can result in death, serious injury, or equipment damage.

The fact that a circuit breaker has tripped does not fix the cause of the fault detected on the downstream electrical equipment.

Follow these steps to reset the circuit breaker after a trip caused by an electrical fault.

Step	Action		Position
1	Push the toggle handle from the (Trip) position to the O (OFF) position. The circuit breaker is open.		O (OFF)
2	Take precautions to protect yourself.	–	O (OFF)
3	Look for the cause of the detected fault.	–	O (OFF)
4	Clean and test the downstream equipment and the circuit breaker.	–	O (OFF)
5	Push the toggle handle from the O (OFF) position to the I (ON) position. The circuit breaker is closed.		I (ON)

Testing the Trip Mechanism

CAUTION
HAZARD OF NUISANCE TRIPPING Circuit breaker 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).

Follow these steps to test the trip mechanism.

Step	Action
1	Push the toggle handle from the O (OFF) position to the I (ON) position. The circuit breaker is closed.	I (ON)
2	Press the push-to-trip button. The handle moves from the I (ON) position to the (Trip) position. The circuit breaker is tripped.	(Trip)
3	Push the toggle handle from the (Trip) position to the O (OFF) position. The circuit breaker is reset.	O (OFF)

Step

Action

Position

Push the toggle handle from the O (OFF) position to the I (ON) position.

The circuit breaker is closed.

I (ON)

Press the push-to-trip button.

The handle moves from the I (ON) position to the (Trip) position. The circuit breaker is tripped.

(Trip)

Push the toggle handle from the (Trip) position to the O (OFF) position.

The circuit breaker is reset.

O (OFF)