I need to install a shunt trip?

Question

I have a building with an elevator, I have been told that it needs a Shunt Trip wired through a Heat Detector to deactivate the Elevator.

All I can tell you is, the Elevator is 60A 220V, so have been told that is what my shunt unit should disconnect, but how do I wire the incoming power? The Heat detectors that we used elsewhere in the building are 24v wired from a Class B wiring, using single pair wiring, and E.O.L resistors. Can I use power from my Fire Alarm Panel, or do I have to use a different Heat Detector, what do I need to do, and how do I wire it?

Answer 1

A shunt only allows a junction for electricity to flow around a circuit, so a shunt trip is a circuit that is monitoring another circuit and designed to disconnect input voltage/circuit breaker...etc What is the trip value and do you have an interface relay to disconnect the primary circuit?

Answer 2

If you are used to working with contactors, you could understand how to wire a shunt trip. Contactors are relays that can open and close electrical circuits. Application of power to the coil causes operation. Removal of power reverses the operation.

A shunt trip is similar, except it has to be externally, usually manually, reset. The intention in this situation is that once the detector senses heat, elevator drive power should shut down, and not power up without human intervention.

This may not be a do it yourself project, due to the complexity and the number of authorities who might be involved. Elevator codes, fire codes and building codes need to be considered.

Your fire detectors have normally open circuits. If you are permitted to use the fire alarm control panel to initiate action, it must present a normally closed circuit to the shunt trip in an approved manner. If you operate the shunt trip directly from a fire detector, it must have a closed circuit. You can find detectors rated for 120 VAC.

Be sure all the authorities will be satisfied before you spend any money on equipment or installation.

Answer 3

Not a big deal. Just replace your existing 60 amp two pole breaker with a 60 amp two pole "switch neutral" breaker. Order from local electrical supply house. Going to be a bit pricey.