MLO panels as service equipment. - 06/16/02 04:44 PM
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.
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.