Splice on service entrance conductors

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KasseemF

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what does the code say about splices for service entrance conductors where it relates going from a smaller size conductor to larger size.

I have a situation where i have somone who wants to relocate a service, 120/240V service, the have 1/0 AWg currently going to the service point. Is it wrong if they decide to place manhole at the current meter bank and splice a 2/0 AWG cable to the 1/0 AWG from the manhole to the new meter bank? He also wants to go from the hew panel 2/0 and step down to 1/0 witha splice at the manholde to go inside.

Also I would like to know what are the safety issues involved because I feel that there will be overheatingon the 1/0 AWG service conductor
 
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tom baker said:
Service Entrace conductors are sized to the calculated load. Do a load calc and see where you are at.
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The calculated load must be less than the smallest wire rating used within the splice

Is that a correct statement?
 
True statement.
Also I would like to know what are the safety issues involved because I feel that there will be overheatingon the 1/0 AWG service conductor
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If the load calc is less than the rating of the wire, should not be an issue.

POCO still needs to buy off on it. It may be their wire
 
Just a litte more clarity

Just a litte more clarity

My concern is the service boint being to a 1/0 and then there being a 2/0 after that?

Isn't their a possibility of overheating on the 1/0?

So that is fine?

If I am an electrical inspector inspecting this i should approve it?
 
The service drop conductors are always smaller than the conductors in the service mast. Partly because POCOs are in open air, partly because they size theirs differently. It is not uncommon to see a small aluminum triplex connected to a larger copper too.
 
iwire said:
The NEC allows splicing service conductors, the utility may or may not allow it.
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Bob, I fail to see how the serving electric utility has anything to say about what is done on the load side of the service point except where we plug in our cash register. I do know that some will attempt to throw their weight around but they can be overruled if you want to go to the trouble. :confused:
 
KasseemF said:
My concern is the service boint being to a 1/0 and then there being a 2/0 after that?

Isn't their a possibility of overheating on the 1/0?

So that is fine?

If I am an electrical inspector inspecting this i should approve it?
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This would depend on what the load on the 1/0 is. Asking if it is correct or not without knowing the load does not give enough information to answer your question. What size OCP is it feeding? :-? :-? :-?
 
charlie said:
Bob, I fail to see how the serving electric utility has anything to say about what is done on the load side of the service point except where we plug in our cash register. I do know that some will attempt to throw their weight around but they can be overruled if you want to go to the trouble. :confused:
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Did you notice where Kasseem is from? Anguilla. I doubt if any of use have the slightest idea what is going on as far as the utilities are concerned down in the islands. The government may own the utilities down there, who knows ( it's not a big place ).

Kasseem is the engineer and electrical inspector so my advice would be to make them do whatever he feels is safe. Sounds like it will be his butt that's on the line if something goes wrong.
 
I think i finally got my head around what your talking about but i had to visualize it. I see two manholes out side,
one for the purpose near the existing meters and one for the purpose of entering the building.

Ill bet you what the guy is thinking is ...... "if my splices become an issue with heat, I want to make sure that my short section with a splice on each end can absorb the heat.

If anything goes wrong at all, its probably gong to effect the service drop form the utility before it effects your wiring going inside.

Arent you guys down there also suppose to have a fused / breaker disconnect on the outside of the building?,, and then from the disconnect you wire to the inside??

If thats the case, then electrically it may get frowned on here in the states,, and i would not do it. I would just co-ordinate with the local power company to pull a straight shot. cost must be an issue here so its probably going to be your call.
 
charlie said:
Bob, I fail to see how the serving electric utility has anything to say about what is done on the load side of the service point except where we plug in our cash register. I do know that some will attempt to throw their weight around but they can be overruled if you want to go to the trouble. :confused:
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If the utility has 'no splices in service conductors' in their service book and that has been approved by the utility commission IMO they can refuse service.

I don't see this as much different then the utility saying I can't run a huge intermittent load in my building. They have rules I have to abide by or they can refuse or terminate service.
 
Here are a couple examples from a local utility of their influence beyond the service point.

507. Unmetered Conductors
Unmetered conductors shall not be installed in the same raceway with metered conductors. When unmetered conductors are installed through private basements or other private areas not containing NSTAR equipment, they shall be enclosed in a continuous length of exposed rigid raceways or conduit conforming to Massachusetts Electric Code. The installation of pull boxes, fittings or other similar devices is not permitted in such areas.

In a block of stores, the unmetered conductors shall be enclosed in a rigid metal raceway or encased in concrete with the approval of the authority having jurisdiction.
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602. Fluctuating Loads
Loads such as electric welders, furnaces, boilers, compressors, pumps, molding machines or similar equipment with load fluctuations shall not be installed, except under conditions specified by NSTAR. Please contact the NSTAR Tech Center to advise of the prop osed installation of this equipment.Voltage dips caused by load fluctuations, regardless of their frequency, must not cause undue disturbance to other customers nor hinder NSTAR in maintaining proper voltage conditions. For customers served by a dedicated transformer on single phase lines, welders should conform to NEMA-EEI Standards and not draw more than 46 amperes at 240 volts. (Please see more specific details in Article 804)
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iwire said:
Here are a couple examples from a local utility of their influence beyond the service point.
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You are indeed correct, we have the same rules with different wording.
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