I specified a 42 space Cutler-Hammer (Eaton) panel for mainly lighting and receptacle loads. However, the contractor installed a 48 space panel, thus it won't pass inspection. Is there any way to keep the 48 space panel intact, but permanently remove the ability to use spaces 43-48? Does Eaton make some device to do this?
Limiting 48 space panel to 42 spaces
- Thread starter Kuzu
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Limiting 48 space panel to 42 spaces
I think that "permanent removal" would require cutting the bus bars. That could not be done in the field without participation by a manufacturer's representative (or you would lose the UL label). I agree with BruceH: you need to call Eaton.
I think that "permanent removal" would require cutting the bus bars. That could not be done in the field without participation by a manufacturer's representative (or you would lose the UL label). I agree with BruceH: you need to call Eaton.
rcwilson
Senior Member
- Location
- Redmond, WA
Re: Limiting 48 space panel to 42 spaces
I bought an Eaton power distribution (not appliance and lighting) 208/120 panelboard with a main and sub-feed, 48 spaces total. The factory incorrectly assumed that the 42 pole rule applied and defeated the top 6 CB spaces by pop-riveting the tapped holes in the vertical bus bars where the cross bus bars connected.
We talked to the factory and got permission to drill out the pop rivets and install some spare bars from an unused panel to install our required breakers.
Talk to the supplier, maybe you can remove the cross bars and pop rivet the holes. Saves cutting the bus.
I bought an Eaton power distribution (not appliance and lighting) 208/120 panelboard with a main and sub-feed, 48 spaces total. The factory incorrectly assumed that the 42 pole rule applied and defeated the top 6 CB spaces by pop-riveting the tapped holes in the vertical bus bars where the cross bus bars connected.
We talked to the factory and got permission to drill out the pop rivets and install some spare bars from an unused panel to install our required breakers.
Talk to the supplier, maybe you can remove the cross bars and pop rivet the holes. Saves cutting the bus.
james wuebker
Senior Member
- Location
- Iowa
Re: Limiting 48 space panel to 42 spaces
Does the 42 space rule only apply to homes? If this is an industrial building would the 42 space apply to it or is more allowed? I know I've put in panels that have up to 54 spaces. Maybe I'm thinking of Canada.
Jim
Does the 42 space rule only apply to homes? If this is an industrial building would the 42 space apply to it or is more allowed? I know I've put in panels that have up to 54 spaces. Maybe I'm thinking of Canada.
Jim
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Re: Limiting 48 space panel to 42 spaces
Actually the 42 circuit applies everywhere that NEC 408.34 and 408.35 apply.
But there is nothing in the code that says a 48 ciruit panelboard is not allowed. The only restriction is not more than 42 devices are actually installed.
This is another case of an inspector trying to prevent some possible future occurence. Granted it is likely that the extra spaces might be used, but it is also likely someone will use tandems if the extra spaces were not provided.
The only way to prevent a future misuse is to have all new circuits installed by somone who knows and follows applicable codes.
Actually the 42 circuit applies everywhere that NEC 408.34 and 408.35 apply.
But there is nothing in the code that says a 48 ciruit panelboard is not allowed. The only restriction is not more than 42 devices are actually installed.
This is another case of an inspector trying to prevent some possible future occurence. Granted it is likely that the extra spaces might be used, but it is also likely someone will use tandems if the extra spaces were not provided.
The only way to prevent a future misuse is to have all new circuits installed by somone who knows and follows applicable codes.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Limiting 48 space panel to 42 spaces
I don't have my 2005 handy. But the 2002 says that there must be a physical means to prevent the installation of more than 42 overcurrent devices.
growler
Senior Member
- Location
- Atlanta,GA
Re: Limiting 48 space panel to 42 spaces
I just looked in the 2005 NEC. Physical means is still in there. I would think that drilling the tapped holes out would stop someone from adding more breakers but the company wouldn't get to sell you a listed device. I liked the old days when common sense was still of value. But it doesn't have a UL label.
I just looked in the 2005 NEC. Physical means is still in there. I would think that drilling the tapped holes out would stop someone from adding more breakers but the company wouldn't get to sell you a listed device. I liked the old days when common sense was still of value. But it doesn't have a UL label.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Re: Limiting 48 space panel to 42 spaces
The physical means is to prevent you from installing more circuits than the panel was designed for, not to prevent more than 42 circuits. This also part of the CTL requirement from UL.
The physical means is to prevent you from installing more circuits than the panel was designed for, not to prevent more than 42 circuits. This also part of the CTL requirement from UL.
growler
Senior Member
- Location
- Atlanta,GA
Re: Limiting 48 space panel to 42 spaces
Sorry Jim, I didn't read the whole code. So that puts everything back on the honor system. After reading that the manufacturer had bothered to put rivets in the bolt holes I just made the assumption there was a reason. I think we all should have been lawyers, it would have been easier, if the glove doesn't fit you must acquit.
Sorry Jim, I didn't read the whole code. So that puts everything back on the honor system. After reading that the manufacturer had bothered to put rivets in the bolt holes I just made the assumption there was a reason. I think we all should have been lawyers, it would have been easier, if the glove doesn't fit you must acquit.
lady sparks lover
Senior Member
Re: Limiting 48 space panel to 42 spaces
I saw an application like this, and they meerly put orange stickers on the spaces left. I was appalled, but it passed the inspection.
I for one would cut the bus bars to ensure this.
Lady
I saw an application like this, and they meerly put orange stickers on the spaces left. I was appalled, but it passed the inspection.
I for one would cut the bus bars to ensure this.
Lady
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: Limiting 48 space panel to 42 spaces
I agree with Jim. 408.35 limits the number of device that are installed, not what might be installed. The physical means provision is to prevent more circuit breakers than the
design, rating, etc. allows.
I agree with Jim. 408.35 limits the number of device that are installed, not what might be installed. The physical means provision is to prevent more circuit breakers than the
design, rating, etc. allows.
rcwilson
Senior Member
- Location
- Redmond, WA
Re: Limiting 48 space panel to 42 spaces
My earlier post was wrong. It was a GE, not an Eaton panel. The panel had space for 42 circuits, plus a vertical main circuit breaker at the top and a vertical sub-feed breaker at the bottom, both connected direct to the bus. GE's fabrication facility said the sub-feed breaker used three of the allowable spaces, so the top six breaker spaces had to be blank. They did not have a good way to defeat just three spaces on a three-phase panelboard.
I believed that the 200A panel internals could handle 42 circuits. Its interior was identical to the 42 circuit MLO panels we had on the project, except for the sub-feed breaker. The panel was protected by a 150A Main CB and the typical load on each 20A CB was 500 VA . (Motor space heaters, solenoids, HVAC control power, etc.)
I have difficulty seeing where the 42 circuit limitation provides additional safety in cases like this or in other industrial situations.
My earlier post was wrong. It was a GE, not an Eaton panel. The panel had space for 42 circuits, plus a vertical main circuit breaker at the top and a vertical sub-feed breaker at the bottom, both connected direct to the bus. GE's fabrication facility said the sub-feed breaker used three of the allowable spaces, so the top six breaker spaces had to be blank. They did not have a good way to defeat just three spaces on a three-phase panelboard.
I believed that the 200A panel internals could handle 42 circuits. Its interior was identical to the 42 circuit MLO panels we had on the project, except for the sub-feed breaker. The panel was protected by a 150A Main CB and the typical load on each 20A CB was 500 VA . (Motor space heaters, solenoids, HVAC control power, etc.)
I have difficulty seeing where the 42 circuit limitation provides additional safety in cases like this or in other industrial situations.
southernboys
Senior Member
Re: Limiting 48 space panel to 42 spaces
This may be a stupid question. If the lighting and appliance panel is limited to 42 ocpd where would one use a 48 ocpd panel. I cant recall ever seeing one and always thought 42 was the magic number so thanks for teaching me something
This may be a stupid question. If the lighting and appliance panel is limited to 42 ocpd where would one use a 48 ocpd panel. I cant recall ever seeing one and always thought 42 was the magic number so thanks for teaching me something
- Location
- Massachusetts
Re: Limiting 48 space panel to 42 spaces
A distribution panel (power panel)
growler
Senior Member
- Location
- Atlanta,GA
Re: Limiting 48 space panel to 42 spaces
I always thought that the 42 rule on lighting & appliance panel boards was to keep down heat and prevent nuisance tripping of breakers. You have the neutrals taking up some space in the panel. I'm sure the fine folks at the NFPA have their reasons.
I always thought that the 42 rule on lighting & appliance panel boards was to keep down heat and prevent nuisance tripping of breakers. You have the neutrals taking up some space in the panel. I'm sure the fine folks at the NFPA have their reasons.
rcwilson
Senior Member
- Location
- Redmond, WA
Re: Limiting 48 space panel to 42 spaces
I figure the 48 spaces are for 42 branch breakers and two 3-phase main breakers. (Yes, two mains are allowed, I guess for Normal & Emergency or split bus applications?)
- Location
- Illinois
- Occupation
- retired electrician
Re: Limiting 48 space panel to 42 spaces
We often use 54 circuit panels for our electric heat trace systems. We specify that the breakers have a bell alarm contact (contact that changes when breaker trips) and this takes an extra space.
Don
We often use 54 circuit panels for our electric heat trace systems. We specify that the breakers have a bell alarm contact (contact that changes when breaker trips) and this takes an extra space.
Don
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