Client Bought URD (Triplex), can they run an additional USE wire for Neutral?

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crash_93

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Kingston WA
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Hey All!

My client bought 115' of URD cable for a run from the meter to a new garage they are building. Problem is by code we are required to install an outside disconnect which means we need to run 3 conductors and a ground wire. URD is 2 conductors and a "Neutral".

Client can't return the cable, and would like to use it if possible. I want to recommend that we use the URD cable and run an additional 4/0 USE-2 wire along side the cable. The 2/0 on the cable can be used as the ground, and the additional 4/0 can be used as neutral. Before recommending this to the client I wanted to make sure my thought process was right.

Thanks!
 
Allowable, but please note the various limitations on USE and URD such as pointed out in this thread:

URD, USE-2, MHF

Had inspector want URD for the mobile home feeder. Now my understanding is URD is not even recognized by the NEC as an allowable wireing. Was going to use the USE but not listed to come into the building. I see MHF, but don't see that in that in the NEC. Is that allowed under the code to both...
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Yup! I confirmed with the Client the cable they have also has RHH and RHW printed on it.

My understanding is it can be used inside with conduit. Please correct me if I'm wrong :)
 
With that dual rating, you are correct.
Be sure the same holds true for your USE
 
Is an external 'service disconnect' (service equipment) required (which necessitates separation of neutral and ground) or is an 'emergency disconnect' acceptable for this installation?

In other words, double check that you really need separate conductors.

Code is generally moving to require separation of ground and neutral, but there are still situations where you simply run a neutral and use it for bonding.

-Jon
 
winnie said:
Is an external 'service disconnect' (service equipment) required (which necessitates separation of neutral and ground) or is an 'emergency disconnect' acceptable for this installation?

In other words, double check that you really need separate conductors.

Code is generally moving to require separation of ground and neutral, but there are still situations where you simply run a neutral and use it for bonding.

-Jon
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I don't understand the claim by the OP that 4 wire is needed because there is an outdoor disconnect......🤔
 
crash_93 said:
Hey All!

My client bought 115' of URD cable for a run from the meter to a new garage they are building. Problem is by code we are required to install an outside disconnect which means we need to run 3 conductors and a ground wire. URD is 2 conductors and a "Neutral".
Click to expand...
Will the disco be at the meter or at the garage?
 
electrofelon said:
I don't understand the claim by the OP that 4 wire is needed because there is an outdoor disconnect......🤔
Click to expand...

In general you are required to have separate neutral and EGC downstream of the service equipment. I'd say this is the most common situation under current code. I was encouraging the OP to look at the exceptions to this requirement.

-Jon
 
See 230.40, Exception #3. You can run a second set of service entrance conductors from the meter, on the line side of the house service disconnect, to the garage and not need the 4th conductor.
 
Sorry for the delay! The layout for the electrical run is:

Street --> overhead to a Well House. This is where the Class 320 meter is.
From the meter it breaks into two circuits.
1. A small breaker for the well house which has a main disconnect for the house
2. To a disconnect for the new Garage, and then underground to the garage it's self.

I guess theoretically if we moved the garage disconnect closer to the structure we could avoid needing the EGC, but the concern is the power company is calling for grounding to happen at the meter. If that's the case I believe we would need the EGC anyway.

Please let me know your thoughts!
 
Sight unseen it sounds like the situation the fellows described above in post #10 & #11. Barring a local or POCO rule, you could connect an UG service run directly to the 320 meter and run to the garage with 3 wire, no EGC necessary.
 
Got it! Sounds like I'll have to talk to the local inspector. At this point we have the 4th conductor so if we need it we have it :)
 
crash_93 said:
I guess theoretically if we moved the garage disconnect closer to the structure we could avoid needing the EGC, but the concern is the power company is calling for grounding to happen at the meter. If that's the case I believe we would need the EGC anyway.
Click to expand...
Grounding at the meter does not change whether you have service or feeder conductors.
 
crash_93 said:
Hey All!

My client bought 115' of URD cable for a run from the meter to a new garage they are building. Problem is by code we are required to install an outside disconnect which means we need to run 3 conductors and a ground wire. URD is 2 conductors and a "Neutral".

Client can't return the cable, and would like to use it if possible. I want to recommend that we use the URD cable and run an additional 4/0 USE-2 wire along side the cable. The 2/0 on the cable can be used as the ground, and the additional 4/0 can be used as neutral. Before recommending this to the client I wanted to make sure my thought process was right.

Thanks!
Click to expand...
If needing an EGC in that sort of situation I'd probably just run a #4 aluminum as the EGC, that is all 250.122 requires, presuming you do have 200 amp OCPD in the mentioned disconnect. If you have no OCPD then IMO it is still service conductors and a EGC isn't needed.
 
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