Parts of a Kirk Key System

Understanding the components that make up a trapped-key interlock

Kirk Key (Trapped Key)

The removable key that transfers between locks. It can only be removed when the associated equipment is in a safe state.

Lock Housing

The cylindrical housing that contains the lock mechanism. It is typically mounted directly on or near the equipment being protected.

Interlock Mechanism

The mechanical linkage that connects the lock to the equipment. When the key is inserted or removed, it controls whether the equipment can operate.

Mounting Provisions

Brackets, plates, or adapters that allow the lock housing to be securely attached to various types of electrical equipment.

Bolt / Locking Bolt

The mechanical element that physically prevents equipment operation. When extended, it blocks movement of circuit breakers, switches, or doors.

Key Transfer Block

A multi-lock device that allows one key to be exchanged for another, enabling complex sequential interlocking schemes.

How Parts Work Together

1

Switchgear Lock

2

Key Transfer

3

Padmount Lock