# Smaller neutral on 3 phase high leg delta



## gpop (May 14, 2018)

My understanding is you treat the neutral size based on the calculated neutral load but not smaller then 70% of the possible load on the low legs. 

So on a 100 amp high leg delta you still need to run a neutral that can handle 70 amps even if you only need 5 amps.


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## u2slow (Jan 2, 2014)

This is where the rules ask for more than the physics requires...


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## micromind (Aug 11, 2007)

Since the high leg does not involve the neutral, you'd treat it as a single phase system.


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## 460 Delta (May 9, 2018)

This isn't really answering your question so much, but the numerous high leg Deltas I'm around, neutrals generally are full size or one wire size down. I've said this before, ready-mix loves their 230 high leg Deltas. I just love pulling #8 wire to 10hp motors.


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## CMP (Oct 30, 2019)

It needs to be big enough to handle fault currents, even if there are no neutral loads.

That would depend on it it's a service, feeder or separately derived.


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