OK for service disco/feeder breaker to be larger than subpanel main breaker?

N

newservice

Senior Member
Location
Syracuse NY
Occupation
Electrician extraordinaire
I feel embarrassed to ask but they finally got around to requiring the outside service disconnects here. So I'm about to put one in, Milbank meter- 200A disco breaker-combo unit, running my 4 wires to the main panel (which I will have to get used to calling a sub panel now). Having the panel breaker the same rating as the service breaker kind of worries me in case of an overload, which one trips first? Does it matter? Seems I recall that a feeder breaker should be larger than a subpanel breaker. Pretty unlikely to ever happen , just wondering if there's code for this, thanks,
 
infinity said:
No it doesn't matter. The main breaker in the sub-panel isn't even required so if you're concerned about which one trips first just us a MLO sub-panel.
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Yeah it seems so. I considered using a main lug vs a main breaker panel, what do you think? Its residential, 200A 40 space 80 ckt
 
newservice said:
Yeah it seems so. I considered using a main lug vs a main breaker panel, what do you think? Its residential, 200A 40 space 80 ckt
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If the MLO is cheaper I would just use that. Having a 200 amp OCPD in the EM disconnect feeding a 200 amp breaker in the sub-panel is not an issue other than it being redundant and potentially a waste of some money.
 
newservice said:
Yeah it seems so. I considered using a main lug vs a main breaker panel, what do you think? Its residential, 200A 40 space 80 ckt
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infinity said:
If the MLO is cheaper I would just use that. Having a 200 amp OCPD in the EM disconnect feeding a 200 amp breaker in the sub-panel is not an issue other than it being redundant and potentially a waste of some money.
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Perfect, thanks. I'll go see if I can scrounge up a 40 space mlo square d in the HOM line
 
On second thought I'll just use the main breaker panel, since no code against it. Something comforting about being able to shut the panel down without going outside. Plus that's a lot of energized bus bars to work around.
 
newservice said:
On second thought I'll just use the main breaker panel, since no code against it. Something comforting about being able to shut the panel down without going outside. Plus that's a lot of energized bus bars to work around.
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Either way is fine. This is a design issue not a code issue. Since you're doing the design you get to choose.
 
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