wrong voltage

[growler]

An electrician I know upgraded a single phase service to 400 amp three phase for a building that has a laundry mat and about 10 apartments. He put a panel for the laundry and rewired the meters to balance everything. Problem is lack of communication. He told the POCO he needed 120/240, they put in a delta with the high leg which apparently is what they have in that area. They want $10,00 to switch it to a wye. Any way out of this?

There is something majorly wrong with this.

I agree there is something wrong here. If he need the 120/240 then switching over to a wye system isn't going to help either. Why did he think he needed 240V in the first place? Maybe old AC units. If they don't have any three phase equipment why didn't they just stay with single phase.

As Kwired says it doesn't sound like they did much planning at all.

 

[kwired]

Are you counting the grounding conductor? Most of the time I see 240/120 split phase referred to as 1P3W.

I'm pretty sure that most resi services get 1P3W from a single center tapped transformer on one phase of the MV. I find it hard to believe that the utilities would be phasing out 240/120V 1P3W resi services in favor of 208/120V 3P4W.

He said 120/240 4 wire - which would be three phase with a high leg system. He also sort of hinted that the cost of a pad mount configured for this system is typically higher priced and is likely what they are avoiding. It is still simple to build a pole top bank out of 120/240 single phase units. And that seems to be the trend in this area. There are 120/240 three phase pad mounts installed occasionally, but most of those systems are supplied by pole top banks. The biggest issue comes up when you need to upgrade an existing high leg system to higher capacity - then you have to make decisions - switch to 208/120, pay more for the padmount then you might with 208/120, or even switch to 480/277.

 

[JFletcher]

Are you counting the grounding conductor? Most of the time I see 240/120 split phase referred to as 1P3W.

I'm pretty sure that most resi services get 1P3W from a single center tapped transformer on one phase of the MV. I find it hard to believe that the utilities would be phasing out 240/120V 1P3W resi services in favor of 208/120V 3P4W.

I think he's talking about hi-leg 3ph services. There are tons of them here, but they are all pretty old installs. I dont think Dominion is doing any new high-leg installs.

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If he needed 400A 3ph, 400A 1ph isnt going to cut it unless the service demand was poorly calculated on the high side or grossly oversized for future use.

 

[peter d]

we do a lot of things in this part of the Country with a word and a handshake.

Does your poco(s) charge for 3-phase services? If so, I would sure want some official documentation of any plans and communication beforehand.

 

[peter d]

An electrician I know upgraded a single phase service to 400 amp three phase for a building that has a laundry mat and about 10 apartments. He put a panel for the laundry and rewired the meters to balance everything. Problem is lack of communication. He told the POCO he needed 120/240, they put in a delta with the high leg which apparently is what they have in that area. They want $10,00 to switch it to a wye. Any way out of this?

What poco in CT is this that still offers high leg delta? It can't be CL&P as they no longer offer it, so it's UI?

 

[GerryB]

What poco in CT is this that still offers high leg delta? It can't be CL&P as they no longer offer it, so it's UI?

Yes. this is in New Haven. I'll be talking to him this week and will find out exactly what happened.