120v Single Leg???

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truck41trouble

truck41trouble

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Good evening,
For the life of me, I can't figure out why this brand new home I'm building a service for calls for a 200a 120v service. I got the spec sheet from my super, grabbed a pole pig and got to work, only when I went to hook it up I only had 2 wires at the street. A 4/0 hot and a 4/0 service neutral. I'm a troubleman so I do a lot of new services, but never have I seen a 200 amp 1 leg service. Basically the only difference on my end is im not hooking anything up to the center tap of the pig, and I even have a 120v meter!

I would appriciate any insight you guys have, its not my job to recommend anything to customers, but I have a feeling something was overlooked here.

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truck41trouble said:
Good evening,
For the life of me, I can't figure out why this brand new home I'm building a service for calls for a 200a 120v service. I got the spec sheet from my super, grabbed a pole pig and got to work, only when I went to hook it up I only had 2 wires at the street. A 4/0 hot and a 4/0 service neutral. I'm a troubleman so I do a lot of new services, but never have I seen a 200 amp 1 leg service. Basically the only difference on my end is im not hooking anything up to the center tap of the pig, and I even have a 120v meter!

I would appriciate any insight you guys have, its not my job to recommend anything to customers, but I have a feeling something was overlooked here.

Sent from my VS987 using Tapatalk
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I see 120 volt on old houses but have not seen that on a new house. Strange indeed.

Why not parallel the transformer secondaries? You could use a smaller pot.
 
The smallest we stock is a 25kva so that's what new services get unless its a 400 amp which is a 50kva.

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Only thing I can fathom is a customer who specifically wanted it that way, ie does not want to deal with an open neutral. Similar to those who request a low EMF home and get all conduit instead of NM or something to that effect. Either that its not a new home. Let us know, this is really interesting. :happyyes::happyyes:
 
Very weird... I too cant fathom why you'd want 120V service.. worried about an open neutral is like worrying about getting hit by lightning... I hope they have all gas appliances.

eta: I would at least pitch to the customer running triplex now instead of later; any future buyer will want/require a 240V service, and the wire cost is probably the same.
 
Frank DuVal said:
Don't you mean not hooking one of the outside (of the three in a row) terminals? Isn't the center tap the way to get 120 volts across the two terminals you are hooking up?
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If the unit can be re-configured to parallel the two sections you could have a 120 only configuration, and at full kVA rating.

Pole mounted 208/120 wye banks would have 120 across each unit.
 
That's strong words from someone who doesn't understand the circumstances. I have never seen this setup for a residence before so it was quite unbelievable to me also.
And Duval is not correct, I can parallel the secondary windings which bypasses the center tap altogether.

I appriciate all the thoughts on this, and the application is being reviewed again.

Jraef, I dont mean to come off as an a$$ but you can skip over my threads if you have nothing good to offer.

Jraef said:
You're correct, and for that reason, plus the absurdity of the entire concept, I'm calling troll.
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I have seen it for residences before, but every one of them was installed at a time when residences had a fairly limited load. Even seen some with metering upgraded by utility to 120/240 but only one leg was being used by the user.

I don't think any POCO's in this area even offer 120 only service anymore, or if they do is only for old existing installations, if you upgrade much of anything on the service side of things they will want you converted to 120/240.
 
kwired said:
I have seen it for residences before, but every one of them was installed at a time when residences had a fairly limited load. Even seen some with metering upgraded by utility to 120/240 but only one leg was being used by the user.

I don't think any POCO's in this area even offer 120 only service anymore, or if they do is only for old existing installations, if you upgrade much of anything on the service side of things they will want you converted to 120/240.
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FWIW traffic light cabinets and street lights are often fed from a single 120 volt source.
 
mbrooke said:
FWIW traffic light cabinets and street lights are often fed from a single 120 volt source.
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I don't work on those but am not surprised some would be that way either, but OP is supplying a dwelling AFAIK.

That said both 225.39(C) and 230.79(C) require 100 amp 3 wire disconnecting means- however does not mention voltage.
 
truck41trouble said:
Good evening,
For the life of me, I can't figure out why this brand new home I'm building a service for calls for a 200a 120v service. I got the spec sheet from my super, grabbed a pole pig and got to work, only when I went to hook it up I only had 2 wires at the street. A 4/0 hot and a 4/0 service neutral. I'm a troubleman so I do a lot of new services, but never have I seen a 200 amp 1 leg service. Basically the only difference on my end is im not hooking anything up to the center tap of the pig, and I even have a 120v meter!

I would appriciate any insight you guys have, its not my job to recommend anything to customers, but I have a feeling something was overlooked here.
Click to expand...


As an electrician I think that if I needed to do something that odd that I would have to first run it by the power company engineering department.

What I'm getting at is that someone at the utility must know something about what's going on and I would find out before doing any hook up.
 
kwired said:
I don't work on those but am not surprised some would be that way either, but OP is supplying a dwelling AFAIK.

That said both 225.39(C) and 230.79(C) require 100 amp 3 wire disconnecting means- however does not mention voltage.
Click to expand...

Good point about the disconnect, but yahh, the voltage not stated is a loop hole around having 240 volts.

@Truck4trouble: can you post pictures of the setup?
 
jumper said:
Did a google search for 120V services and was surprised when I found a few POCOs right off the bat that offered them. One in Indiana goes up to 200A.
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Many do; but offered with the intent to serve traffic lights, street lights and bill boards. Although if it doesn't specifically restrict dwellings on black and white technically you can play the legal card and hook up a home with that.
 
kwired said:
I have seen it for residences before, but every one of them was installed at a time when residences had a fairly limited load. Even seen some with metering upgraded by utility to 120/240 but only one leg was being used by the user.

I don't think any POCO's in this area even offer 120 only service anymore, or if they do is only for old existing installations, if you upgrade much of anything on the service side of things they will want you converted to 120/240.
Click to expand...

In rural Texas I have seen overhead lines on utility poles with only one wire; they are connected to single transformers at residences.
 
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