Disconnect Required for 120 Vac (per CSA) for Panel?
Disconnect Required for 120 Vac (per CSA) for Panel?
(OP)
Is there anyone familiar with CSA requirment to provide disconnect switch for control circuit inside NEMA Panel?
Basically, I am dealing with a piece of equipment consisting 600 vac for resistance load and 120 vac (step-down from 600 vac) for control circuit. 600 vac feed to high-voltage panel while step-down transformer feeds low-voltage panel for control circuit.
However, my client wishes to provide separate feed for 600 vac and 120 vac but I am not certain of any single point disconnect requirement for 120 vac circuit.
I was looking at option to disconnect the primary side of step-down transformer and separately feed 120 vac to secondary side but my supplier says CSA may require separate disconnect.
Any help feedback would be greatly appreciated. Sorry for my elementary understand since I am not electrical engineer.
Vin
Basically, I am dealing with a piece of equipment consisting 600 vac for resistance load and 120 vac (step-down from 600 vac) for control circuit. 600 vac feed to high-voltage panel while step-down transformer feeds low-voltage panel for control circuit.
However, my client wishes to provide separate feed for 600 vac and 120 vac but I am not certain of any single point disconnect requirement for 120 vac circuit.
I was looking at option to disconnect the primary side of step-down transformer and separately feed 120 vac to secondary side but my supplier says CSA may require separate disconnect.
Any help feedback would be greatly appreciated. Sorry for my elementary understand since I am not electrical engineer.
Vin





RE: Disconnect Required for 120 Vac (per CSA) for Panel?
In my opinion, this inspector (and yours) is confused between industrial equipment and standard installations. According to NFPA and UL508, the machine is to be considered one object with a single disconnecting means.
The problem with the hydro inspectors is that they never seem to be the same twice. As someone from the States, you just smile and nod, then do what they say.
He also told me to replace my supplimentary breaker with a "real" breaker. It was protecting the secondary of the control transformer.
RE: Disconnect Required for 120 Vac (per CSA) for Panel?
DO NOT feed 120VAC into the secondary of the control power transformer (CPT) and just leave the primary disconnected. If you are not using the CPT then remove it from the panel. Shortcuts like that are just plain bad electrical practice. If you are doing the job, do it right.
You're asking about CSA requiring something in a NEMA panel. NEMA isn't a listing agency and CSA doesn't "care" about anything following NEMA standards. So, what is the actual listing that will be applied to the panel?
RE: Disconnect Required for 120 Vac (per CSA) for Panel?
RE: Disconnect Required for 120 Vac (per CSA) for Panel?