Opening, Closing, and Resetting a Circuit Breaker With Motor Mechanism

Introduction

The motor mechanism can open and close a circuit breaker remotely with electrical commands. There are many applications:

Automation of electrical distribution to optimize operating costs
Normal/standby source changeover: changes over to a replacement source to improve continuity of service
Load shedding/reconnection to optimize tariff-based contracts

CAUTION
HAZARD OF REPEATED CLOSING ON ELECTRICAL FAULT Do not modify the wiring diagrams for the motor mechanism. Failure to follow these instructions can result in injury or equipment damage.

Wire the motor mechanism in strict accordance with the motor mechanism wiring diagram in the appendix.

In automatic operating mode, wiring the SDE contact helps to prevent the circuit breaker from resetting automatically on an electrical fault. For more information about the SDE contact, refer to the indication contacts.

Manual Operation: Opening, Closing, and Resetting Locally

Move the selector to the Manu position.

Cycle of operation:

Manual Operation Description

Check that the spring-charged indicator is on charged (A). If not, reset the circuit breaker.

Step	Action	Comment
1	Close the circuit breaker by pressing the closing pushbutton .	When the circuit breaker is closed: The contact position indicator (B) changes to I (ON). The spring-charged indicator (C) changes to discharged.
2	Open the circuit breaker by pressing the opening pushbutton .	When the circuit breaker is open: The contact position indicator (D) changes to O (OFF). The spring-charged indicator (E) stays on discharged.
3	Reset the circuit breaker: recharge the closing spring by operating the charging handle (eight times).	When the circuit breaker is ready to be closed: The contact position indicator (F) stays on O (OFF). The spring-charged indicator (A) changes to charged.

Step

Action

Comment

Close the circuit breaker by pressing the closing pushbutton .

When the circuit breaker is closed:

The contact position indicator (B) changes to I (ON).
The spring-charged indicator (C) changes to discharged.

Open the circuit breaker by pressing the opening pushbutton .

When the circuit breaker is open:

The contact position indicator (D) changes to O (OFF).
The spring-charged indicator (E) stays on discharged.

Reset the circuit breaker: recharge the closing spring by operating the charging handle (eight times).

When the circuit breaker is ready to be closed:

The contact position indicator (F) stays on O (OFF).
The spring-charged indicator (A) changes to charged.

Automatic Operation: Opening, Closing, and Resetting Remotely

Move the selector to the Auto position.

Cycle of operation:

Automatic Operation Description

Step	Action	Comment
1	Close the circuit breaker by sending a close (ON) command.	When the circuit breaker is closed: The contact position indicator (A) changes to I (ON). The spring-charged indicator (B) changes to discharged.
2	Open the circuit breaker by sending an open (OFF) command.	When the circuit breaker is open: The contact position indicator (C) changes to O (OFF). The spring-charged indicator (D) stays on discharged.
3	Recharge the stored energy control by using one of the three reset modes, depending on the wiring diagram: Automatic reset Remote reset by using the pushbutton Manual reset by operating the charging handle	The circuit breaker is ready to be closed: The contact position indicator (E) stays on O (OFF). The spring-charged indicator (F) changes to charged.

Step

Action

Comment

Close the circuit breaker by sending a close (ON) command.

When the circuit breaker is closed:

The contact position indicator (A) changes to I (ON).
The spring-charged indicator (B) changes to discharged.

Open the circuit breaker by sending an open (OFF) command.

When the circuit breaker is open:

The contact position indicator (C) changes to O (OFF).
The spring-charged indicator (D) stays on discharged.

Recharge the stored energy control by using one of the three reset modes, depending on the wiring diagram:

Automatic reset
Remote reset by using the pushbutton
Manual reset by operating the charging handle

The circuit breaker is ready to be closed:

The contact position indicator (E) stays on O (OFF).
The spring-charged indicator (F) changes to charged.

Resetting After a Trip on Electrical Fault

Resetting after a trip on electrical fault can only be done locally. When operating in automatic mode, return to manual operation to reset the circuit breaker.

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 protection has tripped the circuit breaker does not remedy the cause of the fault detected on the downstream electrical equipment.

To reset after a fault trip:

Step	Action
1	Isolate the feed before inspecting the downstream electrical equipment.
2	With selector on Manu, operate the charging handle 8 times to reset the circuit breaker in ready-to-close position. Result: The spring-charged indicator changes to charged (B) and the internal mechanism goes from the Trip position to the O (OFF) position (A).
3	Lock the circuit breaker.
4	Look for the cause of the detected fault.
5	Inspect and, if necessary, repair the downstream equipment.
6	Inspect the equipment in the event of a short-circuit trip.
7	Reset and close the circuit breaker.