REQUEST: Cable + Switch size for a 45kVA load and a 15kVA load!

[smileyrules]

Hello Everybody,

I'm working to supply power to: 1. 45kVA transformer and 2. 15kVA power pack.
the existing splitter is supplied with power from a 600VAC MCC (50Amp breaker); using a 3C #2AWG TECK cable.
What is the cable size I can use to connect to both loads? and,
What is the acceptable rating for the Disconnect Switch that I can install inbetween the splitter and each load?

So far, I'm thinking of using:
for the 45kVA Transformer: 3C #2AWG cable with 60Amp switch.
for the 15kVA Transformer: 3C #12AWG cable with 200Amp switch. is this acceptable?

Any response is appreciated.

Thank you,
Bassam M.

 

[petersonra]

I don't know much about TECK cable since it is not used in the USA, but, #12 wiring fed from a 200A disconnect seems odd to me.

 

[JeffBabineaux]

I assumed you were talking about a 20A switch? That would make more sense for 15kVA at 600V. If that's true, then #12 would be sufficient. Check table 310.15(B)(16).

Maybe someone else can chime in here, because I'm still learning. For a 45 kVA load at 600V, I'm figuring a load just above 40A. Sizing the breaker for that, you would need a 60A switch, but for the cable, #6 would be a step above what is required by ampacity (need #8?). Finally, at the disconnect between the splitter and the loads, if you're installing one for both loads, I would use a 60A (43.3A+14.4A) disconnect switch.

 

[Smart $]

Is the installation under CEC or NEC purview?

Assuming 3Ø transformers, a 50A breaker to supply both seems a bit small. The 45kVA transformer has a rated primary current of 43.3A, the 15kVA at 14.4A for a total of 57.7A... but being small is dependent on the load they power.

You didn't state secondary voltage. As such, secondary recommendations cannot be made.