120/208V Residential?

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shamsdebout said:
Have you come across this? Is this typical for newer homes? I haven't come across expect for a power company handbook.
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I've only seen it in condos and apartment buildings, but only as 1ph.

Everything should work, but understand that heating will be at about 75%.
 
LarryFine said:
I've only seen it in condos and apartment buildings, but only as 1ph.

Everything should work, but understand that heating will be at about 75%.
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I completly agree with 208 in condo's etc. the two pole circuits that need two poles are rated for 208 service, oven, H20, A/C.

I understand the lack of effiency of 208 verses 240, I don't understand the one pole limit so much...
 
Frankly, I didn't seem to understand where 208 device couldn't be used as a two pole source were required!.
WiringDia3PWye1.jpg


This is the same layout that I've worked with when I'm around this type of service.

The Same Here
 
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cadpoint said:
Frankly, I didn't seem to understand where 208 device couldn't be used as a two pole source were required!.
WiringDia3PWye1.jpg


This is the same layout that I've worked with when I'm around this type of service.

The Same Here
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It is used that way. A dwelling unit would be supplied with 3 wires...two ungrounded wires and a grounded one from the 3 phase system.

There are some areas where the utilities will supply single family dwelling units in s subdivision with single phase 120/208 service. As others have said the only issue is the wattage reduction of about 25% for heating equipment.
 
don_resqcapt19 said:
There are some areas where the utilities will supply single family dwelling units in s subdivision with single phase 120/208 service. As others have said the only issue is the wattage reduction of about 25% for heating equipment.
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In Boston and Cambridge there are large residential areas served by these underground 208Y/120 networks with each dwelling only receiving two of the three phases. It seems to work well except for the fact getting a shut down is all but imposable as it will effect so many customers.
 
iwire said:
In Boston and Cambridge there are large residential areas served by these underground 208Y/120 networks with each dwelling only receiving two of the three phases. It seems to work well except for the fact getting a shut down is all but imposable as it will effect so many customers.
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I've seen that too in high rise apartments and condo's. Each apartment will be fed from a riser originating at a meter bank and there will be a common neutral that will be tapped to feed several apartments.
 
infinity said:
I've seen that too in high rise apartments and condo's. Each apartment will be fed from a riser originating at a meter bank and there will be a common neutral that will be tapped to feed several apartments.
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In a high rise I have never seen it any other way then a 3 phase service suppling single phase units.

The areas I was talking about are typically 3.5 story brownstones or similar buildings.

The under ground network is often fed by multiple transformers located underground and spread out, the result is very high fault currents in theses homes.
 
iwire said:
In Boston and Cambridge there are large residential areas served by these underground 208Y/120 networks with each dwelling only receiving two of the three phases. It seems to work well except for the fact getting a shut down is all but imposable as it will effect so many customers.
Click to expand...

The neutral current would be more than the unbalance between A and B in this case at the residential panel.
 
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