How much should it cost to add a circuit breaker?

Question

In this question, I asked about problems between my circuit breaker for a circuit shared by my microwave and sump pump. The conclusion was that another circuit should be added to support the microwave on its own. I have open spots for breakers in the box. Assuming I have an electrician do this job, how much should I expect it to cost? If location is a variable, I'm in central Maryland.

Note that the new circuit could be added to support only the sump-pump in an unfinished basement. So my thinking is that it should be one of the easiest additions possible.

Answer 1

It is fairly simple to add an additional breaker to a box but of course there would be some sort of minimum charge to come out and also the cost of the breaker, so probably around $100.

BUT that assumes the actual line for the sump pump/microwave (the one you want to put on the new circuit) is all by itself. I have seen some interesting wiring in old houses where one thing is wired to the next which is wired to the next and eventually all of it goes back to the same breaker. The electrician might need some time to figure out how the microwave and/or sump pump are currently wired before being able to propose a solution. If this is the case then I would expect a much higher bill (since this is no longer a trivial "install a new breaker" job).

Answer 2

The only way to get an accurate figure for your area is to call a bunch of electricians near you, and they won't be able to give you a really accurate number without seeing it. They should be able to give you a range, though.

The sump pump should be on its own 20A circuit without a GFCI. (GFCI may now be required by NEC 2008 edition. Will update when I know for sure.)

The lights and outlets can stay on the same circuit if the outlets have GFCI protection. They're probably going to want to move the microwave to a different circuit while they're at it- unrelated locations really shouldn't share a common circuit.

If they are making any modifications to a circuit that has anything not allowed by the current electrical code (which it does), they will have to make it all correct.

Answer 3

Parts are cheap

$5 for the breaker ($9 if Square D QO, $50-ish if an obsolete panel like Pushmastic, FPE, Zinsco etc.)

$15-ish for the electrical wire.

???? for the labor.

The labor will vary wildly by the practical difficulty of routing the cable, and will depend on things like the total distance, level of finished-ness in the route areas (finished vs unfinished basement), whether the last guy left you some conduit to use, stuff like that.

That variability is precisely why costing questions are a bad fit for this stack.

Off-load the other loads

Depending on your physical access, it may be better to leave the microwave on this circuit, and move everything else to an alternate circuit. Last I looked, basement outlets and sump pumps tend to be in basements, and basements tend to be unimproved (or under-improved) and easier to install wiring (certainly no harder). So the better plan may be to move the sump pump and/or basement receptacles onto separate circuits.

Leave the basement lighting on the microwave circuit; these days lighting is a very small load, and it's nice to have the basement lights Not go dark when you trip the breaker from running tools.