Service entrance conductors

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Pawngrudge

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I want to use three #1 awg copper conductors for a 150 amp single ph. 220v service. This is overhead service feeder not underground. Can I use a wire that reads THHN or does the insulation have to read THHN/THWN-2. In other words I do I need the W or water rating on the outdoor conductors? Thanks in advance.:)
 
THHN is for dry locations. As George mentioned, your conductor needs to rated for sunlight resistance and for wet locations. Take a look at 310.8(C) & (D) and Article 100 for the definition of: Locations, Wet.


Welcome to the forum. :)
 
Thhn/thwn-2

Thhn/thwn-2

I just want to confirm I understand you and order the right wire cut. If the insulation says THHN/THWN-2 it is suitable for use as service drop conductors.
 
I would use them for the mast, but I have a hard time picturing individual strands for the aerial run - what portion of the run are you talking about?
 
I just need the conductors from the weatherhead to the meter. I'm using one inch and a quarter pvc with three #1 awg. Your telling me that THHN/THWN insulation is acceptable, is that right?:)
 
Pawngrudge said:
I just need the conductors from the weatherhead to the meter. I'm using one inch and a quarter pvc with three #1 awg. Your telling me that THHN/THWN insulation is acceptable, is that right?:)
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That would probably be OK around here.
Unless the inspector was having a bad day, and wanted to see the "sunlight resistant" rating on the conductors.:)

steve
 
hillbilly said:
That would probably be OK around here.
Unless the inspector was having a bad day, and wanted to see the "sunlight resistant" rating on the conductors.:)

steve
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Does this "bad day" inspector enforce the NEC? If so good or bad day the conductors are required to be listed as sunlight resistant. 310.8(D)
 
hillbilly said:
That would probably be OK around here. . .
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I am not addressing the question, just this comment.

I get concerned about this statement. Just because the inspector in 'this' area is OK with the installation or he misses something, you can't just say it is OK. If someone gets hurt because of the installation or there is a fire or fault and the cause is determined to be something that was OK around here and is not in a written amendment to the code, you are on the hook for the damage, injury, or loss of life.

No, I am not picking on Hillbilly, I have seen and heard this before and just making a comment. Trust me, you don't want the jury to decide if it OK or not for you to have done something that is generally OK around here. :)
 
Pawngrudge said:
I just need the conductors from the weatherhead to the meter. I'm using one inch and a quarter pvc with three #1 awg. Your telling me that THHN/THWN insulation is acceptable, is that right?:)
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From the weatherhead, you likely mean from the splice to the service drop conductors. That little bit protruding out of the weatherhead must be both wet location and sunlight-resistant rated.
 
Reference:

ARTICLE 310? CONDUCTORS FOR GENERAL WIRING

310.8 Locations.

...

(C) Wet Locations. Insulated conductors and cables used
in wet locations shall comply with one of the following:
(1) Be moisture-impervious metal-sheathed
(2) Be types MTW, RHW, RHW-2, TW, THW, THW-2,
THHW, THWN, THWN-2, XHHW, XHHW-2, ZW
(3) Be of a type listed for use in wet locations

(D) Locations Exposed to Direct Sunlight. Insulated conductors
or cables used where exposed to direct rays of the
sun shall comply with (D)(1) or (D)(2):
(1) Conductors and cables shall be listed, or listed and
marked, as being sunlight resistant
(2) Conductors and cables shall be covered with insulating
material, such as tape or sleeving, that is listed, or
listed and marked, as being sunlight resistant
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George Stolz said:
I would use them for the mast, but I have a hard time picturing individual strands for the aerial run - what portion of the run are you talking about?
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I have to agree there. Couple years later you would have the nylon jacket hanging off the the conductors...
 
wireguru said:
I have to agree there. Couple years later you would have the nylon jacket hanging off the the conductors...
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Perhaps some heat-shrink tubing on 'em... but then I have to wonder if UV resistant is the same as sunlight-resistant in "listed" terminology. I believe someone else brought this up a while ago about 3M's heat shrink... the spec sheet says it's UV resistant but it is not tested for such under its UL listing.
 
Does the "W" in THWN stand for weather resistant? Also, I have seen a lot of THHN that is rated THHN and THWN... is all newly manufactured THHN dual rated?
 
The "W" stands for wet locations. There are interior locations, not subject to weather, that are considered wet locations.
 
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