A trapped key interlocking solution consists of 3 defined actions: isolating hazardous energy, transferring or exchanging sequenced keys, and accessing the protected area or equipment.  Interlocks are designed specifically with these action in mind to ensure the comprehensive solutions operates effectively.

An isolation interlock is typically the initiating interlock and ensures the isolation of power.  Once the equipment is de-energised, the interlock key is turned, engaging the bolt, blocking the power switch, and releasing the key.  The interlock is now a physical barrier to preventing the equipment from being re-energised.

Now that power has been isolated, the released key can be taken to a transfer or exchange interlocks where there the access keys are trapped awaiting the introduction of the initiating key from the isolation interlock.  Once the initiating key has been inserted and turned in the transfer block, the access key(s) are now released, and the initiating key is trapped.

The access key(s) can now be taken to the access points and inserted into the access interlock(s). Personnel can safely enter the area with peace of mind that the power has been fully isolated and cannot be re-energised until the trapped key solution is followed in reverse.