Installing disconnect

How difficult is it to install a main disconect on a panel without one? The SEC were 1/0 copper.

How difficult is it to make a car “run?” The car is red.

Well, it could be as simple as turning the key, or as complex as building the engine. . .

Do you see where I’m going with this?


It’s easy Dylan, call an Electrician.

Agreed…this is not a DIY forum so I as well wont go into installing a disconnect…contact a local electrician and have it done right.

With that said…it is not difficult if you know what you are doing, I usually say to DIYer’s that if you have to ask it probably means someone else should do it…not being a smart a$$ either…just wanting you to be safe is all as you are going to be dealing with unprotected conductors at some point in a service disconnect installation and it is important to know what is going on…important to know the POCO has removed the meter…and all permits are in place.

Thanks guys. I am in no way going to be performing this type of work, just had a moment of curiosity is all. I, for some reason, have been seeing this in quite a few recent inspections.

Your origianl question as asked CANNOT be answered. Jeff had the best analogy.

Typically are not “added” to services. They are installed from the start.

Can always be added to a service with no disconnection means ahead of it, simply means we have more work to do…but most certainly can be added if the existing panel is not actually compliant with a disconnection means and does not meet the exceptions provided by the NEC®

Agreed it should be engineered into the start of the project, however I see many old homes that have poor electrical systems, no OCPD on the panel itself and do not meet the exceptions layed out in the NEC®.

I have installed a many service disconnetion means ahead of older panels…but true fact is we end up updating the panels anyway…lol

In fact…if the panel is old you may have another option…Eaton® makes a remodel insert that is used alot in replacement of FPE and Zinsco panel by removing the inner guts…replaceing with with their UL Approved insert and it has a main breaker in it…then you have your main breaker…and main OCPD and all done…in that option.

Do a service upgrade or swap out…and install a new panel with a main breaker within it…done…( provided we are talking about closest point of entrance )…

And on the FAR end spectrum…maybe it is a panel that will accept a backfed breaker…and ind. holding clip and space in the panel available for it…another possible option…depending of course on the panel in question.

with the 1/0 CU…if it is the main service panel…and is directly inline with the outside meter…then the service size would I assume be 175A service…if the panel you are speaking of is a remote distribution panel it would be 150A on the 1/0 CU…if remote it should have a disconnection means ahead of it anyway…if not…good reason to recommend an upgrade as those conductors feeding it are not protected…

Thanks for building the engine for us Paul. . . :wink:

is this insert a good switch out for all old panels or just those listed &
keeping market area in mind what is typical cost for this item

Actually it has been used in MANY older panels…in fact I just did one in an old pushmatic panel…removed everything down to the empty enclosure…contacted Eaton® with what I wanted…was a simply 100A rated switch out…conductors were already sized properly…simple…replaced the guts and it is UL approved for the installation.

The insert is not expensive…I believe my 20 CKT 100A insert was about 120.00 around about…my office takes care of the billings and so on…anyway it is just an option for older enclosures…not a solution for all senerios by any means…


It is kinda like the Listed Breaker thing…we see the new CL ( Classified ) breakers alot and they fit in ITE, Seimens, Gould and they have them for Square D QO and Homeline and so on…anyway some will believe they are not listed to go in the manufactures panel unless they say they can…well the UL has said they can…if the manufacturer says their warranty is void if it is done…they open themselves up for a lawsuit because of a legal lawsuit that said manufacturers can’t do that on replacement parts if tested in their equipment and approved by 3rd party…anyway long story short…an insert is only that…an insert…but is a possibly soution for some situations…but not all.

Thanks Paul its always to know other options, I’m in beginning stage of revamping my house and the panel is on the list

Ahh…if given the choice to REVAMP…out with the OLD…in with the NEW…:slight_smile:

Good Grief do electricians have some kind of long distance brain wave connections I just called the electrician and he said the same thing everything new

lol…hey…Old is Old…New is New…we like NEW and shiny stuff…with all technology it evolves and so does equipment and so on. While the design of the circuit breaker has not changed in years…the reliability has with greater quality control…in fact I just took a plant tour 2 days ago in Columbia, MD…these guys are SHARP…SUPER SHARP…

Anyway…give an electrician a choice to work with new or old…well…NEW gets it every time.


As has already been stated by others, more information would be needed in order to be able to give you a more detailed answer. However, I’ll try to help you by explaining the minimum that you are likely to need to do.

In general, it is not easy to install a main breaker in most residential electrical equipment. The equipment needs to be rated as suitable for use as service equipment. You would need to back feed the panel. The main breaker would need to be secured by bolting it in place (riveting is an acceptable means of bolting the breaker) and the grounding and bonding will likely need to be modified.