Different voltage source inside one panel

[hamza_arif777]

Hello everyone

I need some assistance on one of the project that I am working on

I need to replace some PACU. The new ones are rated at 380 V while the older ones are with different voltages (220 and 480)
I am planning to install transformers and use the existing cable

My question is that can i keep multiple voltage source inside one panel? is it allowed? for example 1 of the panel has 2 exhaust fans which need to run at 220 V while my 2 units need to run at 380 V.

Appreciate your response guys

Thanks

 

[zbang]

PACU? (Packaged Air Conditioner Unit?)
Generally, you can't mix supply voltages in a single panel, and by "can't" I mean that with a single buss structure it's not possible. Even if you could, it's a bad idea.

 

[hamza_arif777]

Thank you for your reply
Do you know about any standards which can support your answer? I have tried a lot but unable to find any standards
Plus if i use cables instead of bus bar?

Your kind response is awaited

 

[ggunn]

Thank you for your reply
Do you know about any standards which can support your answer? I have tried a lot but unable to find any standards
Plus if i use cables instead of bus bar?

Your kind response is awaited

Since you are in Saudi Arabia whether the NEC allows it or not isn't an issue. There is no electrical reason I can think of why you could not use a panel supplied with one voltage as a passthrough for conductors of another voltage as long as all the conductor insulation is rated at least as high as the higher of the two voltages. Obviously the busbars have to be one or the other voltage.

 

[paulengr]

It would be impossible to use transformers, drives, and most electronics to say nothing of modern packaged air handlers without muktiple voltages present. I’d love to see a 230,000 V meter operating at 230,000 V.

Three issues come up. Below 50 VAC (DC limit is considerably higher) shocks are not considered fatal. Above about 200-300 V arc flash occurs. Above about 2,000-3,000 V partial discharge becomes an issue. So the rules change with voltage.

As mentioned everything needs to be insulated for the highest voltage in the space but with what you describe everything is 600 V anyway.