replacing panel board interiors

[TWW]

In cases of retrofits (grouted in panelboards, panel boards connected to many RGS conduits with seals etc.) , We have often specified replacing the interiors of old obsolete panel boards with new interiors and covers. The new interiors are much smaller than the old so clearance is not an issue. Some improvising is required to get the new covers aligned properly, however.

We have recently had a "paranoid" contractor refuse to do this work, as this is not a UL listed combination.

Is there a work-around to this issue based on clearances, original UL listing of panelboard can etc. The original equipment is probably thicker gauge steel than the new anyway. There is also more clearance than a new. So there has to be a systematic approach to legally validating what common sense says, i.e. no problem.

 

[CHDean]

UL labeling is a sticky subject. I have retrofitted panelboards into existing tubs many times. I have yet to have AHJ question the validity of UL labeling, normally they are worried about bending radius of feeders. I would use the fact that the steel exceeds NEMA standard and most likely all other specifications and the fact that you are far exceeding minimum cable bending radius standards. As for contractors, they can put their protest in writing and do the work or drag up. You can always get somebody that will do the work.

 

[busbar]

There are programs like

http://www.ul.com/field/

which may also be offered by other NRTLs to individually inspect and so label the modified equipment with regard to appropriate UL standards. They could generate an exceptions report to show due diligence [but potentially acceptable compromise] on the part of engineering staff, facility owner and AHJ.

 

[advidana]

The contractor is right, check with UL it will lose it,s listing. But as busbar stated ul or other testing companies can field certify that it is correct. Check the price first because it may be cheaper to replace the panelboard.

 

[peebee]

I'm under the impression that UL will come visit your site for the low low price of about $10,000. So that's probably not the answer.

However, I'm under the strong impression that if you use a panelboard shop who is certified by the original panelboard manufacturer, that they can do about whatever they want to the panel and it will either maintain the original UL listing, or at least they'll provide a certificate for the panel which is just about as good.

I'd definitely recommend that you get a custom panelboard shop to do this work instead of your contractor.

Actually, I'm kind of surprised that your contractor has the morality and common sense to refuse this work -- to be honest, I've never met a contractor yet that would think twice about attacking a switchboard bus or frame with a drill and a sawzall to make a few little "enhancements" to the original design. Arguments about UL listings usually just make their eyes glaze over and they start mumblling things about engineers under their breath. . . .

 

[WhoJuntao]

You didn't mention if your original SWB was UL listed in the first place! If it wsan't, then get another contractor to do it.

However, if it was, then your contractor is right: smaller equipment will mess up the Form compatmentation, for example if it was Form 4 - Type 7 (as in: you have to be an ... to get yourself electrocuted manipulating this one), the new version won't remain so. I know a silly frame can cost $2000 and that's why you'd like to keep it, so instead of the UL, have someone from the municipality or city hall approve the installation.

 

[JR1948]

At least here in the USA I have had good sucess getting replacement interiors from the original panelboard manufacturer. Even when companies have been merged I've had success. Although I've never researched the listing question, I would suspect that the manufacturer wouldn't sell you the inyterior knowing that you were going to use it for a retrofit if there was any likelyhood of legal ramifications in doing so.

Dick Waltermeyer

 

[rbulsara]

If this installtion is in the USA, UL listing is NOT a code requirement! Code requires that the equipment be either listed or approved for the intended use by a NRTL (nationally recognized testing lab such as UL, ETL, FM approved) or by local authority having jurisdiction (electical inspector).

So the bottom line is cehck with the local inspector and/or fire marshal who may accept a installtion which he deems safe within reasons ( the reverse is also true, he/she can reject a UL listed equipment as well, if deemed unsafe).