How It Works
The sequential locking system between switchgear and padmount equipment
The Key Principle
There is only one key that moves between the switchgear and padmount. This key can only exist in one place at a time, creating an unbreakable chain of safety. If the key is in the padmount, the switchgear is physically prevented from being re-energized.
Start at Switchgear
The key is initially trapped in the switchgear interlock. The circuit breaker or switch is in the closed (energized) position.
Open Switchgear
Open the circuit breaker or disconnect switch at the switchgear. This action de-energizes the downstream equipment.
Release Key
Once the switchgear is open, the Kirk Key can be released from its lock. The switchgear is now mechanically blocked from being re-energized.
Transfer Key
Carry the key to the padmount or equipment that needs to be accessed. The key is the physical proof that the source is isolated.
Unlock Padmount
Insert the key into the padmount interlock. This unlocks the cabinet or access door, allowing safe entry to the equipment.
Work Safely
With the key trapped in the padmount lock, the switchgear cannot be re-energized. Work can be performed safely.
Equipment isolated and accessible
Returning to Service
To re-energize the equipment, the process is reversed:
- 1Close and lock the padmount cabinet
- 2Remove the key from the padmount lock
- 3Return the key to the switchgear
- 4Insert the key, which releases the switchgear interlock
- 5Close the switchgear to re-energize