Multiple services to same property

S

SceneryDriver

Senior Member
Location
NJ
Occupation
Electrical and Automation Designer
Why are POCOs so reluctant to install multiple services of the same voltage/phase to the same property?

My client is a summer theater. The property has the 400 seat theater building, as well as the rest of "camp" which consists cabins for the performers and technicians, the cafeteria, scene shop, costume shop, etc...

They are power starved for several reasons: loads in the theater are have increased over the years due to the needs of productions, and they've expanded the buildings behind the theater (new scene shop, more cabins).

The POCO has offered to set a new padmount transformer at their expense. However, their largest single phase transformer is 167kVA, or 600A. This would be sufficient for the theater building, but the rest of the property needs its own 400A service. And before anyone asks: no, rewiring everything on the property for 208/120V 3-phase isn't a feasible option.

Which brings me to my question - why won't the POCO set two transformers and two meters for the property? It's their technical limitation that's preventing a larger transformer from being installed, and their paperwork limitation preventing two transformers. It looks as though the theater will have to do some ridiculous paperwork shuffle like "Theater Building, a wholly owned subsidiary of Theater Company" to satisfy the POCO while getting its own transformer. I've asked the POCO why they have this restriction, and no one knows, they just do. I can understand the concern with feeding a single structure with multiple services, but these are completely seperate buildings.


SceneryDriver
 
I would bet their calculations show the 167 is adequate for the load. There numbers are much different from the NEC and their transformers can handle overloads well.
 
augie47 said:
I would bet their calculations show the 167 is adequate for the load. There numbers are much different from the NEC and their transformers can handle overloads well.
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I thought that too initially, but the POCO rep even admitted that the 167kVA is too small to support everything properly. They just have this thing about multiple services of the same voltage to the same property. If there's a property line involved, it's apparently fine. Even the POCO doesn't know why the rule exists. I've also heard that this a rule most POCOs follow for some reason.


SceneryDriver
 
ramsy said:
Why no pole transformers, is everything underground?

Poco may not believe load calcs represent actual demand.
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167kVA is the largest single phase transformer they will install, pole-top or padmount. The service is currently pole-top, but the POCO wants to change that to underground at their expense. The overhead wires are old, and the theater often looses power during bad weather. There's apparently an underground line 3000ft down the road that they want to feed from.

They have the billing data and power consumption numbers, and they agree that the service needs to be split into two transformers. They just won't do it to the same property. I've asked about primary metering, and that's apparently a no-go as well. Ironically, it's because the entire new service would be too small.


SceneryDriver
 
I think POCOs have an interest in keeping their costs down by installing fewer transformers and meters. A second transformer and meter is a big capital cost, and more maintenance that they have to maintain forever.


Why not go three phase and send out single phase 120/208 to each structure?

Any idea what the hysterical demand is? It's hard to believe it's anywhere close to 600A. What size transformer is installed now?
 

Why not go three phase and send out single phase 120/208 to each structure?

"And before anyone asks: no, rewiring everything on the property for 208/120V 3-phase isn't a feasible option."
 
electrofelon said:
Yes I am aware of that. If you look at what I said, I was not proposing rewiring anything for three phase.
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If you did not want 120/208 single phase you could also separately derive 120/240.

Though you have to convince POCO, NEC does allow multiple services when the demand is higher than what a utility will supply from a single service. So that is a little bit of a arguing point if you need more than the 167 kVA transformer if that is the largest they will provide.
 
electrofelon said:
Yes I am aware of that. If you look at what I said, I was not proposing rewiring anything for three phase.
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In this case, using two of three phases everywhere probably isn't possible either. Neutrals to many subpanels would be undersized and there's a bunch of gear in the theater that will not play nice with 208V, as they were designed for 240V. The lighting system is the main issue, but they also have some stage machinery that needs 240V single phase to operate properly.


SceneryDriver
 
SceneryDriver said:
In this case, using two of three phases everywhere probably isn't possible either. Neutrals to many subpanels would be undersized and there's a bunch of gear in the theater that will not play nice with 208V, as they were designed for 240V. The lighting system is the main issue, but they also have some stage machinery that needs 240V single phase to operate properly.


SceneryDriver
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Bring in a three phase, 480V service or whatever is the highest voltage available from the utility and set your own 240V transformers for your buildings.
 
You could also get a 480V 3ph service and then step down at each building if it is a big complex. It will also help with voltage drop.

The down side is there will be more equipment for the site to maintain.


* d0nut beat me to it *
 
d0nut said:
Bring in a three phase, 480V service or whatever is the highest voltage available from the utility and set your own 240V transformers for your buildings.
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That could certainly work from a technical standpoint, but it drastically increases costs for the theater and that's not $$ they have. There's also the customer-owned transformer losses they have to pay for, for ever. It's a bureaucratic paperwork issue on the POCO's end that's become a technical issue for the venue.

To take the position to the extreme, if I have 1000 acres and I place structures at opposite ends of the property, would the POCO still force me to cross the entire property for power, since I own the entire plot of land?

In this case it's not like they won't make their money back if they set two transformers and two meters. The venue is on the hook to supply the CT cabinets and secondary wiring, so their only cost is the padmounts - last I checked they require next to no maintenance pretty much ever.

They will likely spin off the theater building into its own legal entity for the purposes of POCO billing. It just seems silly to have these extra hoops to jump through.



SceneryDriver
 
POCOs can certainly be frustrating, they have these standards and policies and getting an exception, even if it makes common sense is often nearly impossible.

A couple more ideas: will they do a second service of a different voltage? And/or do you know if they will supply a high leg Delta? (Even if they do, that would probably need to be served overhead as hardly any pocos want to stock pad Mount delta transformers).
 
I've lost count on how may properties that I have installed separate services on here. Sometimes its just a garage with low power needs. Customer didn't want to feed from their main service. Poco's hardly ever deny it. Matter of fact, the higher meter charge for them will make them more money. Even if the 2nd service uses no power, there is a minimum monthly charge.
 
Sounds like you have multiple buildings, so to separate and provide separate services to a combination of buildings, it wouldn't be a code violation to the NEC.
Have you provided a separated load calculations to the POCO? Having one service to the theater and supporting buildings and a second for the "cabins" or what ever combination there of, on a pedestal mount. You definitely can't run through the theater a second service to the cabins, thus the suggested pedestal mount for the cabins.
The issue might be that this venue is not a full time operation with full loads expected all the time so the POCO investment into a much higher capacity compared to revenue derived from the venue might be a concern to the POCO even though code wise should not enter into the calculations.
But it sounds like the cost/revenue factor is a concern to your customer thus the reluctance to re-wire to 3 phase. Has the POCO even suggested such a scenario to change to 3 phase? Regardless of how you try to accomplish the splitting of the service or increased capacity it will require some significant costs no way around it.
 
Poco’s don’t like large single phase services because it unbalances their lines. I built a service for a store that doubled its size, they had an existing 400 amp single phase service that was loaded to 99% during peak hours. I tried to talk the owner into three phase, which was available at the same pole, but he didn’t want to spend the money, so I built a 1200 amp single phase service. The poco moved the rest of the customers to the other two phases to balance the lines.
 
electrofelon said:
POCOs can certainly be frustrating, they have these standards and policies and getting an exception, even if it makes common sense is often nearly impossible.

A couple more ideas: will they do a second service of a different voltage? And/or do you know if they will supply a high leg Delta? (Even if they do, that would probably need to be served overhead as hardly any pocos want to stock pad Mount delta transformers).
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Funny you say that about the high-leg delta service. That's actually what the property currently has. The high-leg used to serve the AC compressors and air handler for the building, with everything else being single-phase. After the HVAC was updated a few years ago, the only remaining 3-phase load on the entire property is a piece of stage machinery. I'm swapping its VFD out this spring for other reasons (VFD is 17 yrs old and starting to throw random faults) and feeding it from single phase.

The POCO really wants to get rid of the hi-leg service, since they aren't wild about maintaining them anymore, and they don't like the pole-top CT metering for safety reasons. They just don't want to play ball on the multiple transformers issue.



SceneryDriver
 
Little Bill said:
I've lost count on how may properties that I have installed separate services on here. Sometimes its just a garage with low power needs. Customer didn't want to feed from their main service. Poco's hardly ever deny it. Matter of fact, the higher meter charge for them will make them more money. Even if the 2nd service uses no power, there is a minimum monthly charge.
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Must be regional, this has been my experience also. One of my properties had 3@sp and 1@3p when I bought it
 
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