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MLO panels as service equipment. #81022 06/16/02 12:44 PM
Joined: Mar 2001
Posts: 345
tdhorne Offline OP
In another forum I suggested the use of a twelve slot, single phase, main lug only panel as a way of heavying up an existing multi panel installation. I proposed supplying each of several "sub panels" from a breaker in the new service equipment and converting the original service panel from a breaker in the new service equipment after converting it to a lighting and appliance panel board by installing an equipment grounding buss and removing the neutral buss bonding screw.
The problem one inspector on that forum had was that the MLO panels I am talking about using as service equipment can except single pole breakers. He said he would turn down the installation on the grounds that more than six breakers could be installed. An example of the kind of panel I am talking about is a Square D QO112L200GRB. These panels are listed as service equipment. The label reads "suitable for use as service equipment when not more than six main breakers are installed and not used as a lighting and appliance panel board. My approach is to use no breaker under forty amps with a neutral connection in the circuit in the service panel. That means that thirty amp water heater circuits and twenty ampere heater circuits are cool in the service panel but thirty ampere dryer circuits have to go in the panels that are fed from the service.
I have used this approach to heavy up a number of services and I have not had any problem. The inspections all went without a hitch. The reason for asking this question here is that if this one inspector represents a substantial sector of opinion I will take the precaution of getting these installations approved in advance so as to avoid any problem on inspection.

Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
2017 / 2014 NEC & Related Books and Study Guides
Re: MLO panels as service equipment. #81023 06/18/02 08:57 PM
Joined: Apr 2001
Posts: 507
golf junkie Offline

What you propose is accepted practice in the State of Nebraska. Nothing in the NEC prohibits this AFAIK. Everything is open to interpretation by the AHJ.......

Probably it's not worth fighting a battle over. Just get a main-breaker panel, it's a cleaner, safer installation.


[This message has been edited by golf junkie (edited 06-18-2002).]

Re: MLO panels as service equipment. #81024 06/19/02 09:00 AM
Joined: Mar 2001
Posts: 345
tdhorne Offline OP
I might buy cleaner but I won't buy safer. One of the types of properties I use this in is rural residential properties with well pumps. By using an MLO panel to supply the interior panel, the well, other buildings, air conditioning, and so forth I assure that a problem in any one building will not deprive the occupants of the water to fight a fire with until their rural fire department has time to respond. I am aware that the code allows a separate disconnect for that purpose but that adds markedly to the expense of the installation.

Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison
Re: MLO panels as service equipment. #81025 06/20/02 10:26 PM
Joined: Dec 2001
Posts: 437
The Watt Doctor Offline
Sounds like you are building a new service, and using the old service equipment as a subpanel. If your new panel is service rated, and we all know the "6 switch on services" rule, I don't see what the inspector's problem is. To me it doesn't matter that more that 6 breakers could be installed. What matters is, that you install 6 breakers or less. We all know that only trained persons will be working on this equipment, and if a person is trained they should know the "6 switches or less" on services rule. So, the inspector can't assume (and we all know what happens when we assume things, it makes an a$$ out of u and me) that someone is going to, at some time in the future, break the rule by adding another breaker. Sounds like a job for Sam Colt.
No offense to any inspectors out there, or to you junkie. By the way, junkie, how's your game?

At your Service,

The Watt Doctor
Altura Cogen
Channelview, TX
Re: MLO panels as service equipment. #81026 06/21/02 06:00 PM
Joined: Oct 2000
Posts: 5,389
sparky Offline
Inspections should address what is, not what could be IMO.
He/She could just as easily fail my 40 cir. cans on the same premis here.

chapter & verse please....

Re: MLO panels as service equipment. #81027 06/21/02 06:19 PM
Joined: May 2002
Posts: 1,716
Roger Offline
Tom, this guy and his (I AM GOD) attitude is completely out of line. With the right person involved, say one that had the means and time to sue him and his city or county for lost revenues and inconveniece, I would bet he would reevaluate his "rule making" and go back to enforcing the code as it is written. or at least someone above him would see that he did. IMO BTW I read that thread in it's entirety, and you out classed him


[This message has been edited by Roger (edited 06-21-2002).]

[This message has been edited by Roger (edited 06-21-2002).]


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