My wife and I moved into our home 2 years ago(newly built) and the home had an unfinished basement(2 car garage and 2 unfinished rooms). The basement is currently on 1 circuit. Both rooms are now finished and each have 4 electrical outlets. The garage has 3 electical outlets, and there are also 2 outside outlets on the same circuit which would make 13 outlets on the same circuit as well as lighting. As of right now we have had no problems with this set up but I am wondering if when we have 2 garage door openers installed if that would lead to an overloaded breaker. I dont think I would try this project myself, but how difficult would it be for an electrician to put some of these outlets on a seperate circuit? There is space available in the panel for more breakers.

kp2171

not an electrician. there are others here who are pros. heres what i know. others will correct me if ive assumed incorrectly.

it depends on whats running on the circuit. to determine the reasonable capacity of the circuit, you add up the total watts, determine a "safe capacity" and then look at what is going to run on the circuit.

take the breaker amps * 120V to get total watt capacity. if it were a 20 amp breaker, your total capacity would be 2400 watts. then you should calculate a safe capacity by reducing this number by 20% (this might vary based on what you intend to put on the circuit, this is just what ive been told for general use)... would give you 1920 watts. this gives you a little room for things like startup draw and fluctuations.

then you need to add together all thats on the system.

two garage door openers : depends on size... if 1/4 HP, lets assume 600 amps ea with startup, 300 ea running after startup, 1200 both starting at the same time.

these wont be running all the time, or even necessarily at the same time, but if you do decide to open both doors at the same time, and at the same time you have, say a couple of ceiling lights on (estimate 180 watts * 2 = 360watts) and maybe a tv (est 500 watts)... suddenly 1200 + 360 + 500 = 2060 watts. add in exterior lighting and a fan running when the doors are closed/opened and were beyond the safe capacity and pushing the total capacity. experts, correct me here if my math is fuzzy as morning teeth.

again... if you are not opening both at the same time (and im guessing you wont be), that cuts est 600 watts out of the load. but what else are you running on the circuit? a vacuum cleaner can easily draw over 700 watts... so now you cannot vacuum, have a tv and some lights on, and open one door without pushing it. so two 1/4 HP door openers on the same circuit could be anywhere from 300 watts (one running after startup) to 1200 watts (both starting at the same time)... you might get away with one door much of the time (less than a vacuum running), but two at the same time looks a little crowded.

if the basement is still not finished its no big deal to separate, most likely. even if its finished its probably worth the time to get it done right, especially getting the garage off the basement. i know i want to be able to plug in a shop vac or circ saw on the garage outlets and not have to worry about the inside usage.

tkrussell

KP is more right on that I think he realizes. To start with, there is no code for a maximum of outlets on a general purpose circuit in a home. However, common sense and how the outlets can be used in each area come into play here.

The quantity of outlets on a circuit is not important if the outlets dont get used. But if, like KP mentions, you want to use tools in the garage, along with the bedrooms going with something, you can have problems, the least being seeing the lights blinking because of motors starting.

When the basement was unfinished when you moved in, the circuit seemed fine. I would had wired the garage separately, but the way you found it is OK.

Once the two rooms got completed, as I get from your statement Both rooms are now finished and each have 4 electrical outlets., this is where cost or inexperience was a factor.

The basement rooms should had been a separate circuit. The outlets and lights for these bedrooms should also be protected by an Arc Fault breaker.

Who did the wiring for the bedrooms? I suspect these bedrooms just got connected to the lights in the basement, which as you know are also on the garage and the outside outlets.

There also should be a AC-DC interconnected smoke detector in each bedroom, and one out in any common area of the basement. There is, right?

mgfarmer

Thanks for the reply. Not sure if it makes a difference but we are not using the rooms as bedrooms. One is going to be a family room and another is an office. We do have a smoke detecter in the hallway leading to both rooms but not in the rooms. The contractor that finished the basement had his own electrician add the outlets, and all he did was run them off the outlets that were currently in the rooms. With this being our first home I did not think to tell him to put them on seperate circuits. Is it possible that an electrican would be able to move some of the outlets or the garage outlets to a sperate circuit? The panel is located in the garage.

tkrussell

OK I must have imagined the rooms were bedrooms, sorry for the assumption.

If they are not bedrooms, then smokes are not needed in the rooms just the once for that level in the hallway.

I am sure there is a way to get these rooms on their own circuit, just not sure what would be invloved to get to the panel in the garage. I know it is tough when the panel is in the garage, believe I know. if there is no attic above the garage , and the garage is probably sheetrocked, then conduit on the surface of the drywall may be the only method to get wiring to the panel.

If you do use conduit, install a larger conduit than needed, say a 1 ", to allow for future access to add wiring from the home to the garage panel. It is possible than added circuits may be needed later.

ceilingfanrepair

For some reason I thought they were bedrooms too.