bphgravity
Senior Member
- Location
- Florida
408.15 limits the number of OCD in lighting and appliance panelboards. Does this mean that a panel determined to be a power panelboard may have more than 42 devices? 
Power Panelboard
- Thread starter bphgravity
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Re: Power Panelboard
Yes.
Yes.
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: Power Panelboard
I agree. But I don't know what is special about lighting and appliance panelboards, requiring them to have a limit of 42. Anybody know the reason?
I agree. But I don't know what is special about lighting and appliance panelboards, requiring them to have a limit of 42. Anybody know the reason?
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Power Panelboard
I think they figured we needed some kind of limit.
Now with many new homes requiring far more because of computers,intertainment centers ,microwaves,split ovens/ cooktops,2 and sometimes 3 AIR COND.the need for more circuits is very real.If the load is still under the 200 amps there should be no reason to be setting a sub panel next to it just to get the spaces.
I think they figured we needed some kind of limit.
Now with many new homes requiring far more because of computers,intertainment centers ,microwaves,split ovens/ cooktops,2 and sometimes 3 AIR COND.the need for more circuits is very real.If the load is still under the 200 amps there should be no reason to be setting a sub panel next to it just to get the spaces.
Re: Power Panelboard
Square D even makes a 54 circuit power panelboard (with a note in the catalog refering to the 42 circuit rule).
I think I remember reading somewhere that the 42 circuit rule was put into place after a hotel fire was traced to a panelboard with a large number of breakers. I can't remember if that was a post in this forum, or where. Then again, I may be completly mistaken.
Steve
Square D even makes a 54 circuit power panelboard (with a note in the catalog refering to the 42 circuit rule).
I think I remember reading somewhere that the 42 circuit rule was put into place after a hotel fire was traced to a panelboard with a large number of breakers. I can't remember if that was a post in this forum, or where. Then again, I may be completly mistaken.
Steve
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Re: Power Panelboard
Square D also makes the 54 circuit panel for those times when a breaker may take up more than one space per pole (i.e. shunt trip or alarm contacts) and for the additon of plug-on sub-feed lug kits. In the old days they actually had a Q1 frame breaker that took 2 spaces per pole (across the width of the panel).
In any situation not more than 42 circuits can be installed in a Lighting and Applince Branch Circuit panelboard
Square D also makes the 54 circuit panel for those times when a breaker may take up more than one space per pole (i.e. shunt trip or alarm contacts) and for the additon of plug-on sub-feed lug kits. In the old days they actually had a Q1 frame breaker that took 2 spaces per pole (across the width of the panel).
In any situation not more than 42 circuits can be installed in a Lighting and Applince Branch Circuit panelboard
Re: Power Panelboard
Origionaly posted by Pierre:
Arbitrary Numbers
Pierre: Can you provide any reference or link that talks about this. I think the history behind this rule would be interesting.
Steve
Origionaly posted by Pierre:
in:
Arbitrary Numbers
Pierre: Can you provide any reference or link that talks about this. I think the history behind this rule would be interesting.
Steve
- Location
- Bremerton, Washington
Re: Power Panelboard
A power panel board is typically used in industrial applications, with qualified persons who would be aware of the limitiations, it does not have to have a main ocpd
A lighting panelboare by contrast could be found in a restraunt, and its held to 42 spaces and OCPD as the owner otherwise may not realize even though its a 225 amp buss panel its not really 225 amps. In all the commerical and industrial locations I have worked I can't think of one location that would of been called a a power panel.
A power panel board is typically used in industrial applications, with qualified persons who would be aware of the limitiations, it does not have to have a main ocpd
A lighting panelboare by contrast could be found in a restraunt, and its held to 42 spaces and OCPD as the owner otherwise may not realize even though its a 225 amp buss panel its not really 225 amps. In all the commerical and industrial locations I have worked I can't think of one location that would of been called a a power panel.
lady sparks lover
Senior Member
Re: Power Panelboard
I think if you have a panel with all 3phase HVAC loads, that would be considered a Power Panel, and I have those all the time. With all the RTUs on the roof and everything. There is no maximum for a power panel, correct??
I always though that rule was lame, because if you have a double panel, then you're using the same feeder to feed two panels. The only diffence is you have two enclosures with two sets of breakers, but all the loads are still on one feeder.
I think if you have a panel with all 3phase HVAC loads, that would be considered a Power Panel, and I have those all the time. With all the RTUs on the roof and everything. There is no maximum for a power panel, correct??
I always though that rule was lame, because if you have a double panel, then you're using the same feeder to feed two panels. The only diffence is you have two enclosures with two sets of breakers, but all the loads are still on one feeder.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Power Panelboard
Here is a little that my web search turned up:
Trade Slang.Com
Here is a little that my web search turned up:
This was from this site:
Trade Slang.Com
- Status