Appendix D–Key Interlock Systems on Model 6 Main and Feeder Circuit Breaker Units

DANGER
hazard of electric shock, explosion, or arc flash Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, NOM-029–STPS-2011, or CSA Z462. This equipment must only be installed and serviced by qualified electrical personnel. Turn off all power supplying this equipment before working on or inside equipment. Always use a properly rated voltage sensing device to confirm power is off. Replace all devices, doors, and covers before turning on power to this equipment. Failure to follow these instructions will result in death or serious injury.

DANGER

hazard of electric shock, explosion, or arc flash

Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, NOM-029–STPS-2011, or CSA Z462.
This equipment must only be installed and serviced by qualified electrical personnel.
Turn off all power supplying this equipment before working on or inside equipment.
Always use a properly rated voltage sensing device to confirm power is off.
Replace all devices, doors, and covers before turning on power to this equipment.

Failure to follow these instructions will result in death or serious injury.

Model 6 motor control center main and feeder circuit breaker units may be equipped with optional key interlock systems. Two types of key interlock systems are provided. The type of key interlock system installed depends on the type of main or feeder circuit breaker unit.

Circuit Breaker Mounted Key Interlock

Key interlocks for PowerPacT M, P, and R frame manually operated circuit breaker main or feeder units are installed directly on the circuit breaker. Locks are equipped with a roll pin installed perpendicular to the lock shaft.

Key Interlocks Directly Installed on the Circuit Breaker

Verify key lock operation.

Place circuit breaker in the ON position.
Turn the key in counter-clockwise direction. The roll pin arm must bump into the handle.
The key cannot be turned to the engaged (locked) position or removed.

If key lock does not meet these conditions, contact the local field office.

Off Position Key Interlocking Operation

Move circuit breaker handle (A) to the OFF (O) position.
Turn the key (C) counter-clockwise to the fully engaged (locked) position.
Remove the interlock key. The circuit breaker is locked in the OFF position.

If key lock does not meet these conditions, contact the local field office.

Plug-in Unit Mounted Key Interlock

DANGER
hazard of electric shock, explosion, or arc flash This unit contains a key interlock system. Do not modify or relocate this unit. Replace this unit only with an identical unit equipped with a key interlock. Only operate the disconnect operator handle with the key in the vertical position. Only operate the key interlock with the disconnect operator handle in the OFF position. Do not force the disconnect handle or interlock key to operate if resistance is encountered. Failure to follow these instructions will result in death or serious injury.

DANGER

hazard of electric shock, explosion, or arc flash

This unit contains a key interlock system. Do not modify or relocate this unit.
Replace this unit only with an identical unit equipped with a key interlock.
Only operate the disconnect operator handle with the key in the vertical position.
Only operate the key interlock with the disconnect operator handle in the OFF position.
Do not force the disconnect handle or interlock key to operate if resistance is encountered.

Failure to follow these instructions will result in death or serious injury.

Key interlocks are available on plug-in main and feeder circuit breaker units containing PowerPacT H, J, and L frame circuit breakers. These types of units include an exterior operating handle to operate the circuit breaker inside the unit. The key for the key interlock system is accessible with the unit door closed.

Unit OFF, with key removed

Unit ON, with key not removable

Operating the Unit with Key Interlock

NOTE: To avoid damage to the key interlock system:

The interlock key must be in the vertical position when moving the unit operating handle to the ON or OFF position.
ONLY turn the key when the unit operating handle is in the OFF position.
If resistance is encountered, do not force the unit operating handle or the key.
If indications of incorrect operation are found contact Schneider Electric to request repair. See Appendix E–Technical Support of this document.

NOTE: The key can be turned one half turn (180 degrees) from the fully locked to the fully unlocked position. The key must remain in the vertical position (see Unit OFF, with key removed and Unit ON with key not removable) before the exterior circuit breaker operating handle is moved to the ON or OFF position.

Turning the unit on.
1. Insert the key into the key interlock.
2. When the key is initially inserted into the lock it will be in the vertical position and the unit operator handle will be locked.
3. If the key is already in the lock, verify it is in the correct position by trying to turn it counter-clockwise. Do not force the key. If the key is in the vertical position and will not turn counter-clockwise, it is in the correct position.
4. Turn the key clockwise one half turn (180 degrees) to the vertical position to unlock the operating handle.
5. Move the unit operator handle to the ON position.
Turning the unit off.
1. Verify the key is in the correct position by trying to turn it clockwise. Do not force the key. If the key is in the vertical position and will not turn clockwise, it is in the correct position for operation.
2. Move the unit operator handle to the OFF position.
3. Turn the key counter-clockwise one half turn (180 degrees) until it stops in the vertical position. The unit operating handle is now locked in the off position.
4. Remove the key from the key interlock.