Greenhouse- wet location

[LennyDryden]

Most THHN is dual rated THWN.

Doesn't the HH mean High Heat?

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[DrSparks]

Doesn't the HH mean High Heat?

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Yup. Thermoplastic High Heat Nylon-coated. Rated for operating at 90*C. The W rating makes it liquid impermeable. If you look at a piece of THHN wire it will usually have both THHN and THWN on it.

 

[LennyDryden]

Yup. Thermoplastic High Heat Nylon-coated. Rated for operating at 90*C. The W rating makes it liquid impermeable. If you look at a piece of THHN wire it will usually have both THHN and THWN on it.

Thank You.

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[GoldDigger]

But the high heat provision does not apply to wet locations if the alternate listing is only THWN.

 

[kwired]

I would say yes to any portion of it that houses plants.



Yes of course, bathrooms, offices, storage rooms etc.






Did anyone say it was?

NEC may not consider it a wet location. But, when it looks like a giant swamp cooler, and has at least 50% humidity, and a 4 X 30 linear foot wet wall should it be qualified as a wet location?

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Maybe we need to define green house.

If it is a plant production area - more of it is more likely to have wet locations.

Many retail stores have so called "green houses" that are open on a seasonal basis around here, but they are primarily displaying potted plants that are for sale, they don't generally spray water throughout the entire facility, any wiring on the ceiling may seldom if ever get wet.

50% is not high humidity - unless you are in Arizona, New Mexico, Nevada southern California. I'd love to see 50% everyday in July or August in the midwest, so would those in the southeast and on west to Texas. Maybe is some relief toward the northeast, but I bet still is pretty humid at times.

Didn't look before replying - I see you are from Arizona. Ever been to southeast or midwest in July or August?

 

[ActionDave]

But the high heat provision does not apply to wet locations if the alternate listing is only THWN.

Correct, but THHN/THWN 2 is pretty common and lets you use ninety degree rating in wet locations.