Fail Safe configurations for the CT-IFC-CCFxxA

The CT-IFC-CCFxxA has a NO/NC alarm relay that monitors overall system health including the status of the fibre link.

Depending on the intended application this alarm relay can be utilised to control the behaviour of the output relay under fault conditions.

Force relay open on failure of fibre

The following scenario is typically used for emergency 'shut off' applications. The CT-IFC-CCFxxA can be used when the 'shut off' switch is located remotely from the equipment that requires control. A fibre link connects these 2 locations.

Contact Closure Over Fibre - Fail Safe Relay Open — Output relay opens on the loss of fibre

Should EITHER the Push to Break switch be opened OR the fibre link is broken the output relay will open.

Contact Closure over Fibre - Logical Arrangement Relay Open — Both switches need to be closed for the output relay to close

The above drawing shows the logical arrangement. Both the local input (Push to Break switch) and the remote alarm relay, wired in the Normally Closed position, must be closed to ensure that the output relay is closed. A change in either will result in the output relay opening.

Force relay closed on failure of fibre

It is also possible to force the output relay to close on the loss of the fibre link.

Relay over Fibre - Relay close on loss of fibre — Output relay closes on the loss of fibre

Should EITHER the Push to Make switch be closed OR the fibre link is broken the output relay will close.

Relay over Fiber - Logical Arrangement Relay Closes — Either switch can be closed for the output relay to close

The above drawing shows the logical arrangement. Either the local input (Push to Make switch) or the remote alarm relay, wired in the Normally Open position must be closed for the output relay to close.