UL PROBLEM

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pdmtn

Member
Location
chattanoogaTN signal mountain
How would you handle this problem ????? Our inspection found a 100 hp. air
compressor in an Industrial plant with a UL listed Control Panel .... the compressor has all the bells and whistles needed for Industrial use ..... here is my problem .... the Control Panel and the inner workings and motor are listed ....Do you feel that it all needs to be listed as an Assembly.... Thanks for your thoughts.
 
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stew

Senior Member
Location
federal way,washington
We once had this problem here in Seattle with an inspector who would not pass an installation of a belt driven compressor I think about the same hp. It had a control panel that was listed as an assembly. It had a motor with a UL component listing(Lincoln Electric Motor). He failed the installation because he said the entire unit as a skid mounted unit had to be lsited as an assembly. Our customer nearly had to sue the city to get this passed. It in my opinion was a silly thing to require in an industrial plant. Apparently his issue was that the unit was all mounted on one steel fabricated skid and therefore was an assembly rather thatn 2 separate listed components on separate bases. I did the install and never did find out what happened with the city but the unit has been in operation safely for 10 years now.
 
steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Why would the control panel need a UL listing? In an industrial setting, I'll bet you can find a lot of control panels that don't have a listing.

I don't think everything has to be UL listed.
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
I seem to recall ....

Wasn't there a 'forensic files' column, maybe a year ago, in one of the trade magazines, that discussed this exact issue?

The author of that article was most scathing in his condemnation of non-listed assemblies like the one the OP describes. I almost think the author asserted a listing requirement. The author certainly claimed that there were quite a few air compressor 'manufacturers' who did little but bolt together various components that were made elsewhere, and inferred that many such operations were marginal, and many such assemblied failed to meet various industry standards.

IIRC, the specific assembly in that column was a compressor that was mounted on a trailer, and used in milking cows. I also seem to recall a great many other issues with the installation, and the maintenance of it.

At any rate, I'll bet that's what the inspector is also remembering.
 
pete m.

pete m.

Senior Member
Location
Ohio
From the 2008 NEC:

409.2

Industrial Control Panel. An assembly of two or more components consisting of one of the following:
(1) Power circuit components only, such as motor controllers, overload relays, fused disconnect switches, and circuit breakers
(2) Control circuit components only, such as pushbuttons, pilot lights, selector switches, timers, switches, control relays
(3) A combination of power and control circuit components
These components, with associated wiring and terminals, are mounted on or contained within an enclosure or mounted on a subpanel. The industrial control panel does not include the controlled equipment.

Perhaps show this to the inspector

Pete
 
mbeatty

mbeatty

Senior Member
Location
Illinois
petersonra said:
Does UL even list industrial compressors?

The control panel listing only covers the control panel itself.
Click to expand...

Our air compressor control panels are UL-508A Listed, but not the entire package. We do use UL/UR rated components, but our UL Listing only pertains to the control panel.
 
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