250.96 (a)

[ivsenroute]

Had to fail large industrial control cabinets with 2 hinged doors. The doors are on a hinge and both doors have control lights mounted on them.

The doors lacked a bonding jumper from the main enclosure to each swinging door. Inside the cabinet were soft starts, contactors, heaters and an AB Remote I/O rack. The main disco was only mechanically connected to the door when the door was in the closed position.

Contractor told me the doors are part of the enclosure but in my opinion are not electrically continuous. In the past I had always bonded these doors since they are hinged.

I feel as though 250.96(A) would apply and this is the first time I have not seen the doors bonded. I suppose the resistance is from the fact that they have 27 cabinets @ 2 doors each cabinet to bond which is an easy task.

Do you automatically bond these doors on very large, hinged cabinets?

 

[LarryFine]

Do you automatically bond these doors on very large, hinged cabinets?

Isn't that up to the manufacturer, if not field assembled?

 

[ivsenroute]

Isn't that up to the manufacturer, if not field assembled?

It can be or shalll I say should be.

 

[augie47]

If it was a factory assembled control panel with a NRTL label it is the opinion of most of the AHJs in this area that under the provisions of 90.7
we are not empowered to inspect that equipment.
All I can say is.. "nice label, nice paint job"

 

[nhfire77]

So the panel is listed, but you want to fail it because you don't like how it was listed????? The cabinet doors were part of the listing. You are making up a rule now. I agree that 250.96(a) applies if there was no NRTL label, but you have clearly stated there is.

I agree they should be bonded, but you cannot decide to apply the code to the inner workings of a listed piece of equipment.

That's like opening the cabinet to a device that is listed, but hardwired by me and pointing out something inside the machine and failing it. If you don't like how it was made, that is not the electricians problem, is it?

Ivsenroute: Would you fail and installation based on this hypothetical situation?

 

[jim dungar]

UL508A and NFPA79 both 'require' the doors to be bonded with jumpers only if they have devices mounted on them operating at > 24V.

 

[mivey]

So does that mean we can bash ivsenroute or not? If the manufacturer "got around" it somehow and got the equipment listed, then what?

 

[nhfire77]

UL508A and NFPA79 both 'require' the doors to be bonded with jumpers only if they have devices mounted on them operating at > 24V.

I did not know that. I love this site.

 

[specgrade]

I'd need to see a picture :grin:

 

[raider1]

So does that mean we can bash ivsenroute or not? If the manufacturer "got around" it somehow and got the equipment listed, then what?

If the lights are 24 volts or less it appears that the UL standards permit the door to not be bonded with a bonding jumper. So my guess is that the manufacture did not "get around" anything but instead followed a standard that does not require the door to have a bonding jumper.

Chris

 

[augie47]

So does that mean we can bash ivsenroute or not? If the manufacturer "got around" it somehow and got the equipment listed, then what?

In my world... we might "suggest" a bond would enhance safety.
Normally that's all thats needed on minor items, but, in doing so, is a piece of "listed" equipment being altered.
If it really stuck in our craw, we could contact the listing agency

 

[pfalcon]

So the panel is listed, but you want to fail it because you don't like how it was listed????? The cabinet doors were part of the listing. You are making up a rule now. I agree that 250.96(a) applies if there was no NRTL label, but you have clearly stated there is.

I agree they should be bonded, but you cannot decide to apply the code to the inner workings of a listed piece of equipment.

That's like opening the cabinet to a device that is listed, but hardwired by me and pointing out something inside the machine and failing it. If you don't like how it was made, that is not the electricians problem, is it?

Ivsenroute: Would you fail and installation based on this hypothetical situation?

Hoffman and most industrial cabinet makers provide a bonding provision for the doors. If you need it then you have to field connect it.

UL508A and NFPA79 both 'require' the doors to be bonded with jumpers only if they have devices mounted on them operating at > 24V.

NFPA79 : 2007 : 8.2.3.6.1 contains no exclusion based on voltage. If you mount to a conductive door or cover then you require a bonding jumper.

 

[pfalcon]

In my world... we might "suggest" a bond would enhance safety.
Normally that's all thats needed on minor items, but, in doing so, is a piece of "listed" equipment being altered.
If it really stuck in our craw, we could contact the listing agency

The listing is that if you require bonding and make proper use of the bonding provision then you're good. If you don't mount any devices on the door then you don't need the jumper. So no, you are not altering a listed piece of equipment. You would be bonding it in accordance with the listing when required. Kind of like 3-wire vs 4-wire appliances.

 

[ivsenroute]

This is a retrofit and being completely field wired for operation with remote i/o racks. As I stated, both doors have devices on them. FYI, the devices are 120v. There are studs for grounding at the base of the doors near the hinge. There is not a bonding wire connected to the studs.

You can bash but it is suppose to be bonded. That stud is not there for looks. I know, I once installed and worked on many of these cabinets.

 

[augie47]

To me that's not the point.
The air tanks should have relief valves, the water system should have back flow preventers... my job classification does not include my addressing or enforcing those issues.
Likewise, my authority does not include mandating changes to NRTL listed equipment. It only includes NFPA 70.
If your' jurisdiction includes listed equipment, go for it. Even procure a copy of NFPA79 (or the applicable panel code) and check for any other deficiencies.

 

[ivsenroute]

When you know it is wrong, it is wrong. We can play the game where I request that they contact the manufacturer and get a letter showing the listing without the bond that I already know is suppose to be there or he can install it. Why overlook a safety factor?

Then I suppose I had no right to fail an installation that had 12 #12 THWN wires in 3/4" RMC because it exceeded the fill requirments? Is that even possible?

 

[augie47]

I'm not saying right or wrong as far as Code.
I guess the same brain cells that guide me to enforce the "law", as in legally adopted Code here, also guide me to follow the law, as in enforce what I am enpowered and instructed to enforce. NRTL equipment does not fall under that venue for me so I don't care to look in that cabinet other han to check the E/Cs terminations.
Again, if your job description includes NRTL assemblies, go for it.
I also don't want the liability. If I tell the owner that if he installs those jumpers I "approve" his equipment and the next week it blows the covers across the room I don't want someone saying "the inspector approved it".

 

[roger]

Then I suppose I had no right to fail an installation that had 12 #12 THWN wires in 3/4" RMC because it exceeded the fill requirments? Is that even possible?

Care to tell what you see as being a violation here? Have you looked at the applicable tables in chapter 9?

Roger

 

[benaround]

When you know it is wrong, it is wrong. We can play the game where I request that they contact the manufacturer and get a letter showing the listing without the bond that I already know is suppose to be there or he can install it. Why overlook a safety factor?

Having them get a letter from the manafacturer would be the normal way to go,imo. It's

not a game, it's conformation to all concerned as to what is needed. The saftey factor

would not be overlooked.

 

[sameguy]

With out my book I would say he needed 16 #12.