Where different voltages are fed into a panel is it permitted to isolate them both through the same isolator? For example where you have a Main Fused Isolator for an incoming 3ph supply and a 110Vdc incoming from a UPS? My experience says that as you quite often get auxiliary isolation contacts then it is possible. However should these auxiliary contacts only be used for signalling and therefore cannot be used as a mean of isolation? Also I frequently see 3 or 4 pole isolator used for single phase supply so can you use the remaining contacts to isolate another voltage? Any thoughts would be most welcome.

IET EngX® Wiring Regulations Discussions

Panel Isolators - Different Voltages?

Where different voltages are fed into a panel is it permitted to isolate them both through the same isolator?

For example where you have a Main Fused Isolator for an incoming 3ph supply and a 110Vdc incoming from a UPS?

My experience says that as you quite often get auxiliary isolation contacts then it is possible.

However should these auxiliary contacts only be used for signalling and therefore cannot be used as a mean of isolation?

Also I frequently see 3 or 4 pole isolator used for single phase supply so can you use the remaining contacts to isolate another voltage?

Any thoughts would be most welcome.

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Panel Isolators - Different Voltages?

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