Main Lug Only as a service panel

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conmgt

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2 Phase Philly
I've never had a need to question this until now.
I have a customer who rents the first floor (storefront) of a small two story property. The second floor is residential. Each floor is metered separately from one service drop.
In the basement, the two SE cables each go into a single breaker disconnect. From there, SER cables go up to MLO panels for each tenant.
My customer wants to put a kiln in the basement. My idea is to replace the existing single breaker disconnect with a 4 circuit MLO panel and feed the kiln with one dbl pole breaker and the MLO panel in her store from another dbl pole breaker.
And I'm thinking that up to six breakers total would be allowed.
Does a service panel need a main breaker? Is there a UL listing that defines a panel as suitable for a service? I've always had service panels needing many breakers but this time, I just need to deal with a feeder and one two pole branch circuit.
 
It is not about main breaker versus MLO. It is about being able to turn off all power to the building with no more than "6 throws of the hand." So if you have two breakers in your new panel, and you don't touch the one breaker that serves the second floor, and if the three breakers are "grouped together," you meet the requirement. I believe the notion of "service rated" has to do with the ability to land neutral and ground wires on terminals that are bonded to each other. So to address that part of your question, I would ask where and how the neutrals and grounds of the two services are bonded in the present configuration.
 
You can have up to six disconnect for the Service. That number would include all service enclosures, so you can do as proposed. NEC requires that service disconnects be listed as such, but most MLO panels will carry that listing with a noataion that no more than six breakers can be used if its a service.
You just need to make sure your added load does not cause the service cable ampacity to be exceeded.

(Charlieb...sorry was slow typing as you posted)
 
Siemens 4 space panel E0408ML1125SU states that it needs to be backfed with a breaker to qualify as a service panel. I'm seeing that it's important, as always, to read the fine print. That panel won't work for me.
 
So what protects the SE cable? I'm thinking that you would not be able to have those breakers in the panel total more than the rating of the SE cable.
If you're dealing with a 100A SE cable into a MLO panel and the six or less breakers total more than 100A, you could possibly overload that SE cable.
 
It is not about main breaker versus MLO. It is about being able to turn off all power to the building with no more than "6 throws of the hand." So if you have two breakers in your new panel, and you don't touch the one breaker that serves the second floor, and if the three breakers are "grouped together," you meet the requirement. I believe the notion of "service rated" has to do with the ability to land neutral and ground wires on terminals that are bonded to each other. So to address that part of your question, I would ask where and how the neutrals and grounds of the two services are bonded in the present configuration.

Yes, turn off the building with six throws grouped together, not just a panel.

and augie said the same.
 
So what protects the SE cable? I'm thinking that you would not be able to have those breakers in the panel total more than the rating of the SE cable.
If you're dealing with a 100A SE cable into a MLO panel and the six or less breakers total more than 100A, you could possibly overload that SE cable.
Actually, where there is more than one service overcurrent protective device, the service conductors only have to be sized for the calculated load, no matter that the total of the ratings of the OCPDs is.
 
Siemens 4 space panel E0408ML1125SU states that it needs to be backfed with a breaker to qualify as a service panel. I'm seeing that it's important, as always, to read the fine print. That panel won't work for me.
That is typical of many panels, especially ones rated at 200 amps or less.
 
Actually, where there is more than one service overcurrent protective device, the service conductors only have to be sized for the calculated load, no matter that the total of the ratings of the OCPDs is.

Yeah, that I understood. But on a project where there's a chance a hamfisted home owner/property owner/DIY/handyman can get involved, there could be trouble.
I've just decided on putting an OCP on this SE cable.
 
I just looked at the fine print on all SqD 100A MLOs...70A max breaker for either branch or feeder or back fed main duty.
Their 125A has no such restrictions.
 
If the 125 amp MLO panel is used with the 6 disconnect rule you may be surprised to learn that most are not suitable for service equipment unless a main breaker kit is installed. Don showed me that one and I was totally unaware of it but I usually put a main in rather than the 6 disco rule
 
Cutler Hammer BR816L125SDP

"In accordance with NEC, suitable for use as service equipment when a main breaker is used or when not more than 6 service disconnecting mains are provided and when not used as a lighting or appliance panelboard"

So without a main breaker, this can't be used for branch circuits? Only feeders?
 
I wish the manufacturers would update their labeling. The concept of a Lighting & Appliance panelboard went away in the 2008 code book. In the OP's case, this will probably work as he's most likely going to have a 50A and 100A breaker in the panel, which would have put him into the Power panel definition instead of Lighting & Appliance panel under the old definitions.
 
You can have up to six disconnect for the Service. That number would include all service enclosures, so you can do as proposed. NEC requires that service disconnects be listed as such, but most MLO panels will carry that listing with a noataion that no more than six breakers can be used if its a service.
You just need to make sure your added load does not cause the service cable ampacity to be exceeded.

(Charlieb...sorry was slow typing as you posted)

I love your "slogan" at the bottom of your posts and know how that is! :)
 
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