nema 12 hoffman box rated for outdoors?
- Thread starter walla
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
walla said:
What are you asking? If they are UL listed for the application it is not up to the inspector. What application are you asking about ? And are these the boxes
justdavemamm
Senior Member
- Location
- Rochester NY
My handy chart says "... intended for indoor use". Show me something that says outdoor use. All mine say indoors. Get a Nema 3 rated enclosure for falling rain / ice outdoor use. Or a dual rated 4/12 one.
- Location
- Bremerton, Washington
Hoffman sells a kit that puts a drip shield and SS hinge pin on a NEMA 12 to make it suitable for outdoors. I prefer NEMA 3R with a gasket, but this is a custom fabrication item
walla
walla
Thanks for the responses, you all have the same interpretation I have of a nema 12 enclosure. I got off my lazy ass and dusted off my code book and found article 430.91 motor controller enclosures types. This is the application that is in question. I had a vendor show up at the job I'm working at with a motor controller enclosure that is a nema 12. It is to be installed outside. I told him it is rated for indoor use only. I thought that was the end of the story. The next day my boss said he had a conversation with the electrical inspector and he the inspector would OK the nema 12 enclosure to be installed outdoors. I wanted to find out if there is any way an inspector can over ride a UL listing.
walla
Thanks for the responses, you all have the same interpretation I have of a nema 12 enclosure. I got off my lazy ass and dusted off my code book and found article 430.91 motor controller enclosures types. This is the application that is in question. I had a vendor show up at the job I'm working at with a motor controller enclosure that is a nema 12. It is to be installed outside. I told him it is rated for indoor use only. I thought that was the end of the story. The next day my boss said he had a conversation with the electrical inspector and he the inspector would OK the nema 12 enclosure to be installed outdoors. I wanted to find out if there is any way an inspector can over ride a UL listing.
walla
walla
Thanks for the responses, you all have the same interpretation I have of a nema 12 enclosure. I got off my lazy ass and dusted off my code book and found article 430.91 motor controller enclosures types. This is the application that is in question. I had a vendor show up at the job I'm working at with a motor controller enclosure that is a nema 12. It is to be installed outside. I told him it is rated for indoor use only. I thought that was the end of the story. The next day my boss said he had a conversation with the electrical inspector and he the inspector would OK the nema 12 enclosure to be installed outdoors. I wanted to find out if there is any way an inspector can over ride a UL listing.
walla
Thanks for the responses, you all have the same interpretation I have of a nema 12 enclosure. I got off my lazy ass and dusted off my code book and found article 430.91 motor controller enclosures types. This is the application that is in question. I had a vendor show up at the job I'm working at with a motor controller enclosure that is a nema 12. It is to be installed outside. I told him it is rated for indoor use only. I thought that was the end of the story. The next day my boss said he had a conversation with the electrical inspector and he the inspector would OK the nema 12 enclosure to be installed outdoors. I wanted to find out if there is any way an inspector can over ride a UL listing.
Nema 12
Nema 12
Your last sentance might bring about some lively discussion. IMHO, 90.4 probably give the inspector (or at least the AHJ) the authority he needs to accept the Nema 12 enclosure.
As Tom mentioned, the absence of a shield will allow water to seep to the gasket and, if you are in an area with freezing temperatures, this intrusion will obviously lead to more difficulties when the water freezes. Perrhaps if you expalined the potential problems to your boss or the inspector they might decide diferently.
Nema 12
Your last sentance might bring about some lively discussion. IMHO, 90.4 probably give the inspector (or at least the AHJ) the authority he needs to accept the Nema 12 enclosure.
As Tom mentioned, the absence of a shield will allow water to seep to the gasket and, if you are in an area with freezing temperatures, this intrusion will obviously lead to more difficulties when the water freezes. Perrhaps if you expalined the potential problems to your boss or the inspector they might decide diferently.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
It is pretty common in many plants to install NEMA12 rated equipment outside in areas that are under cover, such as a three sided equipment shed with roof.
I am not entirely sure just what constitutes something being indoors versus outdoors. I don't think the code defines it.
I am not entirely sure just what constitutes something being indoors versus outdoors. I don't think the code defines it.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
It doesn't but, NEMA 250 does:petersonra said:
In the absence of additional markings or modifications the enclosure is not suitable – even if the AHJ accepts it. Remember this – the AHJs generally are not required to accept liability for their own errors.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
tom baker said:
Tom,
I believe Hoffmann says the "drip hood" kit makes the enclosure suitable for NEMA 2 locations, not outdoor. I know of no "listed" method to convert an indoor only enclosure for outdoor use.
Some NEMA 12 enclosures are dual rated for outdoor use with modification (i.e. some Square D disconnects require a drain screw to be removed for NEMA 3R).
- Location
- Simi Valley, CA
An inspector can sign off anything he's willing to live with. Listing and labeling are simply a tool for the inspector to use.
And rbalex, you are only partially correct. If an inspector signs off something that he knows is wrong or simply because he doesn't care, he then loses that protection that is afforded him as an employee of that jurisdiction. His protection is best described as "errors and omissions" which is what people like notaries have, basically if he didn't see it or he was lied to or something was misrepresented, then he has no personal liability.
And rbalex, you are only partially correct. If an inspector signs off something that he knows is wrong or simply because he doesn't care, he then loses that protection that is afforded him as an employee of that jurisdiction. His protection is best described as "errors and omissions" which is what people like notaries have, basically if he didn't see it or he was lied to or something was misrepresented, then he has no personal liability.
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