XHHW-2 Phases with THWN-2 Neutral

Status
Not open for further replies.
P

pcanning87

Member
Location
New York
We have a project specified with all XHHW-2 600V wiring. The contractor says he can’t get enough XHHW-2 in the size for the neutrals. He wants to use THWN-2 for the neutrals instead, while staying with XHHW-2 for the phases.

I’m not seeing anything in the Code that prohibits this, am I missing anything?


Sent from my iPhone using Tapatalk
 
Nothing wrong with that. Even if you had parallel conductors you could use different insulation types as long as you use the same for each parallel conductor by each phase or neutral.
 
XHHW-2 is pretty common as far as I know.

What size, quantity, and color is he trying to get the neutrals in? Cu or Al?
 
pcanning87 said:
We have a project specified with all XHHW-2 600V wiring. The contractor says he can’t get enough XHHW-2 in the size for the neutrals. He wants to use THWN-2 for the neutrals instead, while staying with XHHW-2 for the phases.

I’m not seeing anything in the Code that prohibits this, am I missing anything?


Sent from my iPhone using Tapatalk
Click to expand...

Are the specifications for use of XHHW-2 for the job stated in writing in a specification book? The contractor might want to contact the EE and get a variance for using THWN-2 in place of XHHW-2 in writing.
 
More Info

More Info

Thanks guys, a little more background - We're the owner on the job (it's a solar project), so the specs are both ours and the EEs. The EE signed off on the THWN-2, I'm really deciding whether we should waive our XHHW-2 requirement in this case, and/or if we expect any Code issues from the inspector. It sounds like there's no Code issue, so it's just up to us whether we as the owner are okay with the change.

I personally think the XLPE is better than nylon/PVC, but I'm not too worried about THWN-2 for this application.

P.S. It's just #2 AL XHHW-2....didn't think that would be too hard to find. My first reaction was to tell the contractor to look harder or upsize it, but we'll decide if it's worth the fight.
 
No code problem with it, but it is worth telling him to look harder. It is out there.

XHHW is worth it if the application is appropriate. Underground (wet all the time) or in conduit exposed on a surface like a roof.
 
Is the calculated neutral load lower enough to use a smaller conductor(s) in an available size?
 
ron said:
No code problem with it, but it is worth telling him to look harder. It is out there.

XHHW is worth it if the application is appropriate. Underground (wet all the time) or in conduit exposed on a surface like a roof.
Click to expand...
I agree. I have had to order it in certain colors but it was always available with in a matter of a few days.

Roger
 
Status
Not open for further replies.
Top