Tapping Service conductors?

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rubob

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I have a project where they would like to wire six vacation cabins with individual 125 amp panels but feed them with one service. The power company suggested a CT cabinet. I am unclear as to whether or not it is permissible to join the service conductors in the CT cabinet with six sets of 1/0 smaller service conductors and extend them directly underground to the individual service disconnects on each cabin. Is that permissible since it is all outside and underground or do I need to go from the CT directly to overcurrent protection and then do feeder taps?
 
rubob said:
directly to overcurrent protection and then do
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I would think from a design standpoint having lets say a 400-600 Amp main, may make sense for shutting the whole area down in one swoop especially in the event of an emergency, especially if the cabins are far apart. Continuing an unprotected utility potential onto lets say a private property with no possible disabling mechanism could result in a potentially liable or undesirable condition.

Sure whats the odds you may say .. even if its 1 in a 1000 , that's still to many.
It's all up to the city plan checker and/or installer, Personally I'd tend to want a main disconnect before dividing it off to 6 individual main panels.

I presume each cabin will have its own meter or is there just 1 site meter.
 
Another C10 said:
I would think from a design standpoint having lets say a 400-600 Amp main, may make sense for shutting the whole area down in one swoop especially in the event of an emergency, especially if the cabins are far apart. Continuing an unprotected utility potential onto lets say a private property with no possible disabling mechanism could result in a potentially liable or undesirable condition.

Sure whats the odds you may say .. even if its 1 in a 1000 , that's still to many.
It's all up to the city plan checker and/or installer, Personally I'd tend to want a main disconnect before dividing it off to 6 individual main panels.

I presume each cabin will have its own meter or is there just 1 site meter.
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Customer wants one meter for the whole site with disconnects on the outside of each cabin.. I agree with your point but it is also true that laterals are run to structures all the time without protection. I feel it will probably go as you say because beyond the CT cabinet it is our responsibility. Trying to determine code minimum.
 
Not much different than if you had installed separate meters on each cabin and had POCO supply services to each one other than you are metering at one location. You will likely find it more ecomonical to tap individual services from one or two central points.
 
augie47 said:
Not much different than if you had installed separate meters on each cabin and had POCO supply services to each one other than you are metering at one location. You will likely find it more ecomonical to tap individual services from one or two central points.
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But there is a difference between 6 services and 1 service with 6 sets of service conductors. IMO for it to be 6 services, the serving conductors would have to terminate to POCO equipment not customer equipment. The only way I see to to possibly have it set up with one service and serve each cabin with service conductors is 230.40 exception one or three, which both seem kind of like a stretch.

You could put a main disconnect after the CT and then come off the load side using the outside unlimited tap rule to each cabin. Or you could come off the CT to six individual service disconnects that would serve each cabin, that actually might be cheaper than one large disconnect and then you would have a means of disconnect for each cabin which might be nice.
 
I agree with the practicality of a disconnect but OP asked about Code minimum. I know of nothing that would prevent multiple taps from the CT nor do I see any violation of a common service to "tap" boxes with "taps" to each cabin.
 
If the main disconnect was after the ct where ever it was located, wouldn’t all bonding at grounding have to take place from each cabin to that disconnect if there was water piping at each cabin?

Then what ? A redundant ground and neutral back to each cabin from the disconnect ?

Or would each cabin get the two ground rods and the water pipe would bond to the separate equipment ground?


Wondering.
 
ritelec said:
If the main disconnect was after the ct where ever it was located, wouldn’t all bonding at grounding have to take place from each cabin to that disconnect if there was water piping at each cabin?

Then what ? A redundant ground and neutral back to each cabin from the disconnect ?

Or would each cabin get the two ground rods and the water pipe would bond to the separate equipment ground?


Wondering.
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No, only the electrodes present where the service disconnect is would need to be used. Any qualifying electrodes at each other structure would be part of the GES for that structure.
 
This has been very helpful. In looking over electrofelons referral to 230.40 it says a service lateral shall supply only ONE set of service entrance conductors, so that would appear to negate the service 'taps' to multiple cabins. I will take his suggestion for overcurrent protection at the CT cabinet and follow conventional tap rules or hopefully convince the client that individual services to each cabin would be more cost effective.
Many thanks all, much appreciated!
 
rubob said:
This has been very helpful. In looking over electrofelons referral to 230.40 it says a service lateral shall supply only ONE set of service entrance conductors, so that would appear to negate the service 'taps' to multiple cabins.
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I'm finding the language in 230.40 a bit confusing as to the above. Per the definitions, for underground services, you have:

Utility - Service Lateral (Utility Owned) - Service Point - Underground Service Conductors (Customer Owned) - Service Entrance Conductors.

And the first sentence of 230.40 (omitting the overhead terms) says "Each . . . set of underground service conductors, or service lateral shall supply only one set of service-entrance conductors."

So for the case that you have both a service lateral and one or more sets of underground service conductors supplied by the service lateral, which is it, each set of underground service conductors, or each service lateral?

230.40 aside for the moment, a service lateral could presumably serve multiple sets of underground service conductors, each of which serves one set of service-entrance conductors. Is that allowed under 230.40? Because that is the arrangement you'd have if the CT can is the service point, which is remote both from the pole and from the cabins, and from there you ran individual sets of underground service conductors to each cabin.

I feel like 230.40 is using the phrase "set of underground service conductors or service lateral" to cover the cases where there is only one or the other. I.e. if the service point is on the pole, there's no service lateral, just a set of underground service conductors. While if the service point is at the meter on the building, then there's no underground service conductors, just a service lateral. Which leaves this ambiguity when there is both a service lateral and one or more sets of underground service conductors.

Cheers, Wayne
 
rubob said:
hopefully convince the client that individual services to each cabin would be more cost effective.
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I'm not sure what your affiliation is with the clients project but the designer /contractor etc .. should not let an investor determine the design, ideas concepts, budgets are their choices ..we are the ones that mention what they can or cannot do legally.
 
Also, a further comment on the scenario I described in my last post, with a CT can remote from the utility pole and from the cabins, with multiple sets of underground service conductors originating at the CT can. If each set of underground service conductors goes to a cabin and terminates on a service disconnect on the outside of that cabin, with no splice or other termination at the cabin, then there are no service entrance conductors at the cabin (see the informational note after the definition of Service Entrance Conductors, Underground System). Therefore there is is no 230.40 violation, regardless of the answer to my previous question.

Cheers, Wayne
 
wwhitney said:
service lateral shall supply only one set of service-entrance conductors
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Besides I'm pretty sure ( in Cal ) each of those individual drops or underground feeds would need to go to a separate addressed meter like
755A, B, C, D, E, F. Maybe go with a 7 gang meter section, 1 being a house meter for property systems .. pole lights electric gate etc ..
 
wwhitney said:
Also, a further comment on the scenario I described in my last post, with a CT can remote from the utility pole and from the cabins, with multiple sets of underground service conductors originating at the CT can. If each set of underground service conductors goes to a cabin and terminates on a service disconnect on the outside of that cabin, with no splice or other termination at the cabin, then there are no service entrance conductors at the cabin (see the informational note after the definition of Service Entrance Conductors, Underground System). Therefore there is is no 230.40 violation, regardless of the answer to my previous question.

Cheers, Wayne
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Yes that had also occurred to me, and I think augie is correct and that there is not a code violation with this. It is a bit strange, I'm curious if that was the true intention of this section.
 
Ignoring the meter at the moment, there is no reason the OP can't do what POCO does every day. Multiple bnranchs off a service at at Quazite box.
Outside conductors are given a lot of latitude,
 
wwhitney said:
Also, a further comment on the scenario I described in my last post, with a CT can remote from the utility pole and from the cabins, with multiple sets of underground service conductors originating at the CT can. If each set of underground service conductors goes to a cabin and terminates on a service disconnect on the outside of that cabin, with no splice or other termination at the cabin, then there are no service entrance conductors at the cabin (see the informational note after the definition of Service Entrance Conductors, Underground System). Therefore there is is no 230.40 violation, regardless of the answer to my previous question.

Cheers, Wayne
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Ive been thinking about this some more. When I focus on that the 230.40 exceptions use the word "service entrance conductors" it seems you get a ton more leeway if you just put an exterior disconnect on the structures. For example look at 230.40 exception #3. I often use that to supply solar PV systems. That section of course only applies to residential settings. But if there are no service entrance conductors because of an exterior disconnect, or something like a "PV array structure" where there would basically never be service entrance conductors, than I can just ignore the whole 230.40 section and run as many sets of service conductors wherever and how many i want, residential or not? :unsure:
 
electrofelon said:
But if there are no service entrance conductors because of an exterior disconnect, or something like a "PV array structure" where there would basically never be service entrance conductors, than I can just ignore the whole 230.40 section and run as many sets of service conductors wherever and how many i want, residential or not?
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Reads that way to me. For those following along, the 2020 definitions:

Service Conductors, Underground. The underground conductors between the service point and the first point of connection to the service-entrance conductors in a terminal box, meter, or other enclosure, inside or outside the building wall. (CMP-10)

Service-Entrance Conductors, Underground System. The service conductors between the terminals of the service equipment and the point of connection to the service lateral or underground service conductors. (CMP-10)

Informational Note: Where service equipment is located outside the building walls, there may be no service-entrance conductors or they may be entirely outside the building.
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Cheers, Wayne
 
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