240V delta I need a neutral

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Wirenutselectrical

Member
Location
Los Angeles
Occupation
Licensed Electrician in California
I have a buddy who has a property, there are 2 structures the first structure is like an office building with 120/240 single phase power. The second structure is a workshop that has 240V delta with a high leg @208V and no neutral running down to the meter socket. However when you trace the over head service feed @ the first building you see 1 hot continues to the transformer bank without touching the first building (im assuming its the high leg) you see the neutral wire tapped going to the workshop & office building and 2 hots also tapped going to the workshop and office building. It looks like a neutral wire is used to support the cable from pole to pole but its not used as a neutral in the work shop. I hope that makes sense. Im telling him we need to add a delta to wye transformer to get 120v safely from 240v delta. But they were convinced by someone else the neutral is there we just have to bring it down from the pole. Can anyone help me understand what is correct thing to do?
 
Wirenutselectrical said:
The second structure is a workshop that has 240V delta with a high leg @208V and no neutral running down to the meter socket.
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Is this the service conductors you are talking about? If so NEC requires grounded conductor to be run to the service disconnect if the system has a grounded conductor. Beyond the service equipment it can be optional if there aren't any loads utilizing the grounded conductor.
 
So one building has 120/240 which means there is a neutral, and the other building has a 208 high leg which means it is from a center grounded Delta, meaning there is a neutral somewhere in the mix.
 
If you are actually reading 208V at the workshop, you're reading it from the neutral to the high leg.
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If you've simply been told it's a 240V delta, it could be with a center-tapped neutral or it could be corner grounded with no neutral.
 
roger said:
So one building has 120/240 which means there is a neutral, and the other building has a 208 high leg which means it is from a center grounded Delta, meaning there is a neutral somewhere in the mix.
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Exactly! And it looks like its being used as support spanning pole to pole however it doesn’t come down to the meter socket for the 240v delta. It just stops up there and 3 hots come down. My question is, is it safe to grab my neutral from there? Or should i install a 120/208 xformer?
 
ptonsparky said:
Yes, bring a neutral down at the second building. Connected to the bare of the overhead. Establish a GES at the second building.

Your AHJ may not like that set up if there are any metallic connections between the two buildings. Water, air, cable etc. YMMV.
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A concern i have maybe you could help me out is the meter is 3 pole straight power no neutral, if i bring that neutral down do you think it’ll mess anything up?
 
Since you are addressing conductors on the line side of the meter I would suggest talking to POCO. See if they have routed the neutral to the service point and how they wish to address metering when you add the neutral to your service panel.
You may need a different meter socket and meter.
Getting a neutral into the shop is seemingly a better route than adding a transformer.
 
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