Does it seem right a 10 Kva transformer draws 1.5A static?

[wyliesdiesels]

The neutral? 480 corner ground has two pole breaker, ground and neutral tied to one phase, (breaker not to break Grounded phase) four wire would be 240/480 four wire. 240 volt stuff connected to phase to ground two phases , wild leg for three phase stuff, three pole breaker.

More common to use 277/480 four wire, more common equipment. Light ballast, exit lights and such. Haven't see much 240V equipment. (240V would probally work at 277V +- 10%)

There is no neutral on a corner grounded delta.

By NEC definition the grounded phase on a corner grounded delta is NOT a neutral.

And you cant have a grounded neutral on a corner grounded delta.

 

[wyliesdiesels]

You made mention of the special breakers needed and the "oddball" nature of the grounded delta. Im used to working with and have access to knowledge of ungrounded therefore it would be a safer and likely cheaper to go the route of ungrounded.

I will have to do it again but I am pretty sure I pulled 500V on all 3 legs to ground when I was installing the mill. I was checking to be sure the disconnect was open/closed when starting/finishing the install. Ill check that out tonight.

Voltage to ground readings on an ungrounded service will vary depending on capacitive coupling.

 

[rlitman]

There is no neutral on a corner grounded delta.

By NEC definition the grounded phase on a corner grounded delta is NOT a neutral.

And you cant have a grounded neutral on a corner grounded delta.

To clarify, by definition, delta does not have a neutral.

 

[wyliesdiesels]

To clarify, by definition, delta does not have a neutral.

A 240v delta CAN have a neutral on one winding.

 

[arkieguide]

I this situation I say - invest in a different service. The transformer as described is doing you no good ? You are probable charged for a commercial are industrial rate. If you don't need it / use it, why keep it? I have wired many building for a 3 phase service but only connected for single phase 220 power. The wiring was there if the next tenant needed it.
Good luck on reducing your elec. bill.

 

[malibu101]

I this situation I say - invest in a different service. The transformer as described is doing you no good ? You are probable charged for a commercial are industrial rate. If you don't need it / use it, why keep it? I have wired many building for a 3 phase service but only connected for single phase 220 power. The wiring was there if the next tenant needed it.
Good luck on reducing your elec. bill.

The local AHJ was cool with a 3 phase panel being fed with single phase??

 

[Paperman]

Ok some real meter readings. 498 P-P on all 3 and 288 P-G on all 3. Couple that with the pics and does that shed light on what’s here? POCO rep is planning a date to come look at the single phase service, I’ll be sure to work over his brain on what 3P is here.

 

[DC73]

That was why I came here asking if the usage is inline with what a dormant transformer should draw or is my 30+ yr. old unit sucking more than its fair share. . . . I was hoping the brain trust here would tell me a standard trans. takes 1% FLA at idle.

As has been mentioned, transformers have "no load" losses. They also have "load" losses. Losses are a function of how well the transformer is designed and constructed. It costs more for low loss transformers. There can be significant differences between low loss transformers and high loss transformers.

The best way to know for sure what you're dealing with is to contact the manufacturer of the transformer and have them give you the losses. Make sure they give you both the no load losses and the load losses. The losses are typically listed in watts and from that information, you can calculate the no load loss in amps and compare it to your own measurement.

The only other way I know of to get the no load losses is to have the transformer tested by a reputable repair shop.

Hope this helps.

DC

 

[wyliesdiesels]

Ok some real meter readings. 498 P-P on all 3 and 288 P-G on all 3. Couple that with the pics and does that shed light on what’s here? POCO rep is planning a date to come look at the single phase service, I’ll be sure to work over his brain on what 3P is here.

That makes it even stranger.

You only have 2 CTs but yet your readings are saying its a 480Y/277 or ungrounded with capacitive coupling being equal on all phases to ground.

Can you pull the cover on your main service panel and take some pics? This would be the first panel where the service entrance conductors go.

 

[Paperman]

I can but it may be a few days. Busy pulling wire and hanging conduit for lights. I had the cover off once and its a pain. About 4' square of 1/8" steel. Heavy for one guy to handle and fasten.

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