Question about UL listing for cabinet and NEC grounding requirements

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teejer

Member
We are a steel cabinet manufacturer, with some of our products UL listed. We recently had an inquiry from a potential customer. The idea is to house a pond aerator in a steel cabinet that would have an access door for maintenance. The aerator would be mounted on the steel cabinet and the aerator has a chord and would be plugged into a separate free standing weather proof GFCI outlet. Depending on the installation, the GFCI outlet comes up through the bottom of the cabinet and is housed inside the cabinet or the GFCI is housed on the outside the cabinet and the chord would pass through a knockout, with a rubber grommett.

My problem is I don't know whether this cabinet should be UL listed or not and I don't know how to treat this cabinet under the NEC, since the cabinet is housing a separate listed device that is chord connected. What I do know is that the aerator is not listed for outdoor use, so it does need a weather proof cover. I also believe that grounding this cabinet with the grounding system of the GFCI outlet would be a good practice because I could see trouble if the chord gets frayed or the steel aerator housing is energized and then energizes the steel cabinet. Without a grounding path, there could be trouble. Does anyone have any thoughts or know of specific sections in the NEC that would call for a listed cabinet here or at least spell out grounding requirements? Thanks in advance.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I don't think it is your problem what someone else puts in a box that you made. The box either meets the UL standards for the type of box you claim it is (e.g.-type 1, 12, 3R, etc.) or it does not. What is in the box is a seperate issue and has no bearing on whether the box can be UL listed or not.
 

teejer

Member
Further question

Further question

Thanks for the reply. I understand what you are saying. Providing them a NEMA 3R rated enclosure that allows for the end user to install their equipment properly, is as far as our responsibility goes.

I have one further question, however, that you may find stupid, but I am trying to cover all of the bases here for all of the parties involved. These aerators are UL listed, but they are not NEMA rated since the intended use for them is in dry locations. Generally speaking, if a cabinet is designated NEMA 3R, then it is considered a dry location, right? That would seem logical since receptacles and other indoor listed components are used all of the time in NEMA3R rated boxes. One item in the NEC that seems contrary to this thinking, at least for a pond aerator, is under article 682.10 (Electrical Equipment and Transformers for Natural and Artificially Made Bodies of Water). It states that "Electrical equipment and transformers, including their enclosures, shall be specifically approved for the intended location." Am I totally reading in to this too much or does the aerator have to be approved for outdoor cabinet use or listed for use in this specific cabinet? Thanks again for your assistance.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
3R enclosures all have drain holes to let water out. The standard for a 3R enclosure says that you have to keep the water off of the live parts, but it can enter the enclosure. I think you need a NEMA 4 to keep the water out.
Don
 
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