UL Listed Enclosures

[firealarmman]

I have heard throughout my professional career that if a UL Fire Alarm Signaling System Enclosure has new wire knockouts drilled into the panel, in leiu of using the factory knockouts provided, that this will void the UL Listing. I have recently ran into this issue and I can't find any documentation to support me. Am I wrong?

 

[roger]

Has anybody ever cited a code article and section that prohibits it? If the manufacturer doesn't specifically disallow it in the instructuions that accompany the listing and labeling then there is nothing wrong with doing it.

There are a lot of these myths out there.

Roger

 

[jim dungar]

Has anybody ever cited a code article and section that prohibits it? If the manufacturer doesn't specifically disallow it in the instructuions that accompany the listing and labeling then there is nothing wrong with doing it.

There are a lot of these myths out there.

Roger

Actually if the manufacturer has provided specific conduit entry points, they must be used in accordance with the manufacturer's directions.

Field drilling/cutting/punching holes in any enclosure may make the UL label invalid. It is up to the inspector to decide if the holes have been made correctly without compromising the enclosure.

I belive this topic is discussed on the UL website.

 

[roger]

Actually if the manufacturer has provided specific conduit entry points, they must be used in accordance with the manufacturer's directions.

And if the instructions don't prohibit field cutting holes elsewhere in the instructions all is fine.

Field drilling/cutting/punching holes in any enclosure may make the UL label invalid.

May is a big word isn't it?

It is up to the inspector to decide if the holes have been made correctly without compromising the enclosure.

Yes it is, per the accompanying instructions, and once again, if the instructions allow it all is fine

I belive this topic is discussed on the UL website.

Can you provide a link please?

Roger

 

[iwire]

Field drilling/cutting/punching holes in any enclosure may make the UL label invalid. It is up to the inspector to decide if the holes have been made correctly without compromising the enclosure.

Interesting, so an inspector can turn down my panel install that I punched holes in because I ordered it without any KOs?

 

[Pierre C Belarge]

Interesting, so an inspector can turn down my panel install that I punched holes in because I ordered it without any KOs?

Bob
I do not believe that is what he is saying. He is saying if the field installation instructions are such that the manufactured KOs are to be used, it would be a 110.3(B) violation to cut your own KOs. If you were to order a backbox that came without KOs, then it would be at your discretion to install the holes according to locations specified by the manufacturer or if not specified by the manufacturer, have at it.


Somewhere I think that I have read the same requirements of KOs... I cannot remember where though. It may be a NYC thing that I remember.

 

[iwire]

He is saying if the field installation instructions are such that the manufactured KOs are to be used, it would be a 110.3(B) violation to cut your own KOs.

I would like to find something official that states KO locations are in fact part of the listing and / or labeling.

I have seen FACPs that had labels in the panel indicating "No Conduit Entry" usually where the batteries sit, or transformers that had labels requiring field wiring to be below a certain point.

In both of those cases I would agree that is part of the labeling.

In the absence of such labeling IMO I can make holes for field wiring at will.

 

[Pierre C Belarge]

I would like to find something official that states KO locations are in fact part of the listing and / or labeling.

I have seen FACPs that had labels in the panel indicating "No Conduit Entry" usually where the batteries sit, or transformers that had labels requiring field wiring to be below a certain point.In both of those cases I would agree that is part of the labeling.

In the absence of such labeling IMO I can make holes for field wiring at will.[/QUOTE]




I agree, and I think most others will as well.



BTW: Who says 2 thick headed Yankees cannot agree?

 

[cschmid]

Now I am guilty here. I have modified holes on enclosures. Never even considered this issue.

 

[jim dungar]

I was too broad with my previous statement concerning knockouts. I intended to say that when a conductor entrance AREA or METHOD has been defined by the manufacturer it must be used.​

Here is a statement from UL (Mark Ode) concerning field modifications.
http://www.ul.com/tca/ec/august04.pdf

Since, by definition, the Listing Mark means the product complied with the applicable UL requirements when it left the factory, any modification to the product in the field could not be addressed by the Listing Mark.


[A] modification may be intentional (such as a repair) or accidental (such as dropping the product). UL cannot know what effect any modification (alteration, repair or accident) may have on safety, code compliance, performance or on the continued UL certification of the product unless specifically evaluated by UL.

Regulatory authorities need to determine if the product is still acceptable or if there is a need to have the product “re-labeled, re-certified, or re-evaluated.” These terms basically address the need for a field service offered by UL in order to determine compliance with UL requirements after field modification of a product bearing the UL Mark.

 

[jim dungar]

In the absence of such labeling IMO I can make holes for field wiring at will.

I agree, however any field holes must be cut correctly (i.e. no "ovals") so that they maintain the integrity of the enclosure. The correctness of the hole is what is subject to the inspector.