gerry
Member
- Location
- New Jersey
Can a sub panel be rated the same as the main for example 200 main panel and the sub at 200 amp or does it have to be less also what article pertains to sub panels.Thanks
sub panel
- Thread starter gerry
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mdshunk
Senior Member
- Location
- Right here.
Re: sub panel
You can hang a zillion amp rated sub panel off of a 200 amp service panel if that is your choice. The rating of the subpanel is just a rating of how "heavy duty" the buss is if you chose to load it fully. The actual subpanel wil be protected by the subfeed breaker in the service panel and will be functionally limited by the size of that breaker.
You can hang a zillion amp rated sub panel off of a 200 amp service panel if that is your choice. The rating of the subpanel is just a rating of how "heavy duty" the buss is if you chose to load it fully. The actual subpanel wil be protected by the subfeed breaker in the service panel and will be functionally limited by the size of that breaker.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: sub panel
I think the '05 code changes that to half a zillion.
Seriously, if you have a 200a main breaker by the meter feeding a main-lug panel, that is exactly this situation; a 200a sub-panel fed from a 200a panel.
I think the '05 code changes that to half a zillion.
Seriously, if you have a 200a main breaker by the meter feeding a main-lug panel, that is exactly this situation; a 200a sub-panel fed from a 200a panel.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: sub panel
I often use separate breakers as a means of powering off a load without turning off others. A disconnecting means if you will. Very handy if you need to work on something.
Panelboards are dirt cheap compared to other ways of handling this problem. the only issue with panelboards is space. Since UL made them so much larger, they eat up a lot of space, so I do this less these days because control panels often do not have the room.
I have had 30 or more breakers in a panel where most of the breakers are only feeding a 100 VA or less load.
I often use separate breakers as a means of powering off a load without turning off others. A disconnecting means if you will. Very handy if you need to work on something.
Panelboards are dirt cheap compared to other ways of handling this problem. the only issue with panelboards is space. Since UL made them so much larger, they eat up a lot of space, so I do this less these days because control panels often do not have the room.
I have had 30 or more breakers in a panel where most of the breakers are only feeding a 100 VA or less load.
bradleyelectric
Senior Member
- Location
- forest hill, md
Re: sub panel
the only time that I have run into where you need a sequencing trip rating is in a commercial installation where a tenant will not have access to the main. You can have a situation where the main is 200A, but you would need where the tenant to have a smaller overload protection so that the breaker that is accessable to the tenant would trip before the 1 that he does not have access to. You can set up an installation where there is a 200 amp disconnect serving as the service, feeding a 200 amp main breaker panel, or a MLO panel as long as the person the main service breaker serves has access to it.
the only time that I have run into where you need a sequencing trip rating is in a commercial installation where a tenant will not have access to the main. You can have a situation where the main is 200A, but you would need where the tenant to have a smaller overload protection so that the breaker that is accessable to the tenant would trip before the 1 that he does not have access to. You can set up an installation where there is a 200 amp disconnect serving as the service, feeding a 200 amp main breaker panel, or a MLO panel as long as the person the main service breaker serves has access to it.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: sub panel
Gerry, I'd like to add to my reply that many panels have a 100-amp-per-lug limit, meaning that a 100-amp breaker should have no breakers opposite it, and a 60-amp should never be paired with anything over 40, etc.
My point is that you may not be allowed to install a 200-amp branch-circuit breaker even if you can find one. The largest I've seen is 125 amps.
Gerry, I'd like to add to my reply that many panels have a 100-amp-per-lug limit, meaning that a 100-amp breaker should have no breakers opposite it, and a 60-amp should never be paired with anything over 40, etc.
My point is that you may not be allowed to install a 200-amp branch-circuit breaker even if you can find one. The largest I've seen is 125 amps.
mdshunk
Senior Member
- Location
- Right here.
Re: sub panel
Sure, a 200 amp snap-in branch breaker is available in all brands that I've ever worked with. For instance, in a QO panel, it takes up 4 slots tall. The older style used to take up two slots tall and two slots wide, but they don't manufacture it that way anymore. The 4 slot tall version is handier if you're snapping it into a NQOD panel. The two tall and two wide version didn't work in an NQOD panel. Sorry for the ramble.
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