All electric devices failed on one of my circuits in my house. The circuit
breaker at the main box didn't look tripped but I find that it isn't always
easy to see they've tripped. When flipping this circuit breaker back and
forth, it feels a little "mushy" i.e. doesn't really seem to click on/off.
I'd like to replace this 15 amp circuit breaker rather that spend about
$100+ for an electrician to do it. I've seen it done before, but haven't
done it myself. Do you experts think it's reasonable for a non-electrician
to be doing this? And, is my approach correct?
My approach would be
a. Turn off the "Main Breaker" at my box
b. Remove the front of the circuit breaker box (4 screws, one on each
c. I'd find the old circuit breaker held in place by 2 screws ????
d. Disconnect the wires from the old one and attach to the new breaker and
reverse above steps.
Also, I have a multi-tester that will test for voltage up to 220. After
exposing the faulty circuit breaker, I could test the circuit to see if it
is in fact dead (I turned the "main" off), before working on it. Question
is: I would attach the + side of the tester to either wire (testing both, I
know one is coming in from the main and the other is going out to the
circuit. I'd test each side to be sure I got the supply side) and the
black side to what??? I could reach the black wire to the grounding wire
outside the circuit breaker box that attaches to a copper pipe running into
the ground, but wouldn't I have an uninsulated 110 v. current running there
when testing. Is there an obvious ground inside the circuit breaker box
that I could touch with the circuit tester black wire?
While this isn't an option unless you replace your box, SquareD makes a
breaker that has a red indicator if it trips.
At this point you want to use your multimeter to check that the main
breaker did indeed work (see below).
Depends upon the model of the box. Residential ones seem to have snap
on breakers. Get the replacement breaker made for your specific box.
I will describe how you would test using a multimeter, because I can't
see your "multi-tester" to know how to use it. When you open your box,
you will see typically 3 thick wires coming in from the utility pole, 2
black, and a white. The 2 blacks connect to the 2 hot buses inside the
box, and the breakers hang off these buses. Don't change the positions
of breakers unless you understand what you're doing.
At this point you can use the multimeter to read 120 V between either
hot bus and the neutral bus, or ground (ground is the box itself or the
conduits). Then turn off the main breaker, and ensure that there isn't
any voltage in the box. When you do stuff like pull breakers off, etc.
you could inadvertently touch stuff, so as a first timer, you want
everything there to be dead. Remember, even if the buses are dead, the
wires from the utility pole coming in are hot, and the things in the
box upstream of the main breaker are hot. Since the breakers for your
house circuits are usually below or away from these, you can avoid
touching these with some care.
Now as regards the circuit whose breaker you are replacing, you will
observe the two wires of that circuit coming into the box (there may be
a ground also, and if it is a shared neutral or 240 V appliance
circuit, there will be 4 wires. But lets assume that they used just 2
wires and used the conduit for ground). Now the neutral wire which is
white, will go to the neutral bus which will be off to one side and
won't have anything to do with the breaker. Just FYI, the neutral is
electrically connected to the ground (which is the box itself, the
conduit, and that wire going to your water pipe). The hot wire will go
to the breaker, just that 1 wire. You'll pull the old breaker,
disconnect that wire from it, and connect to your new breaker, and snap
that onto your panel.
Obviously the things you see when you open your box are connected
eventually to a nuclear power plant, so if you find yourself trembling,
just have someone do it. But it isn't in itself complicated or
There is no + or - side to an AC tester. YOu can use either wire . Not
sure if the tester you have is an actual meter or one of the neon light
types. Anyway, look for a bunch of white wires comming to connection
strip. Hook one lead there and then probe around the box with the other
lead. The only place you should see voltage is where the main two wires
come into the box at the main breaker.
Breakers are not always (not usually ) held in by two screws. They snap in
and the wire going out to the house circuits is under a screw. Make sure
you get the correct brand of breaker for the box you are using as they
probably are not interchangable fron one brand to another.
On the one hand, the hardest thing about replacing a breaker is buying the
right one. Don't know what you have, but many look alike, but aren't right.
On the other, you obviously haven't any idea what you are doing; and getting
instructions off a newsgroup when you have so little understanding isn't a
"Is there an obvious ground inside the circuit breaker box"?!?! Yeah, there
is, but if you didn't know that you probably shouldn't be inside a breaker
Do you have a neighbor who can help you for 5 minutes?
Other than to act as a spotter and call 911 to come pick him up after he
electrocutes himself, what use would a neighbor be, unless he happens to be
an electrician? Some of you regular posters seem to think that your level of
knowledge is normal, and that the clueless newbies on here are the
exception. In my experience, it is the other way around. I know more than
most, because I grew up in construction, but there are still many of the
trades that are PFM to me. (eg, on electrical, I'll swap a breaker, but
would not feel comfortable adding a circuit that came into the panel through
the usual top knockout, right next to those big fat and HOT main leads above
the main breaker. I'm a klutz- I know it, have the scars to prove it, and at
my age, wisdom is the better part of valor.)
I admit that the advice was not very clear. The inferred instructions
was to find a neighbor that knows something about the job. However I have
to admit that having someone around to call 911 is also a good idea.
My inquiring mind prompts me to ask....
Have we already discussed the possibility of incurring personal
liability through gratuitously offered advice on subjects like this?
Especially on a newsgroup, where "the evidence" may be archived forever.
Seems to me that it won't be long before those damn white shoed
liability lawyers will decend upon some knowledgable and helpful person
with deep pockets who responds to a newbie like the OP, after a house
fire or worse ensues.
Perhaps the FAQ for this newsgroup could offer a sample disclaimer
paragraph for pasting into replies or sigs. <G>
Happy Holidays guys,
In general, if you are doing completely for free without any representations
to the contrary, you only need to have slight care. You would be liable if
you told him to test the circuit by grabbing a water pipe and touching a hot
with a licked finger. You would probably not be liable if you neglected to
tell him to turn off a first and he stupidly touched the wire screw on the
breaker. After all, you wouldn't turn off the main first, so why would you
think of telling him to?
Telling this man how to replace his own breaker is a close one. He is
obviously ignorant and likely to do something stupid. But if your
information is accurate... Who knows; personally I think it is
How about, "I don't do this for a living, I don't know what I'm
talking about to begin with and most of my replies are written when
I'm in a liquor-induced stupor. Follow my advice at your own risk."
If you use Agent for news, you can have a separate sig for each
Remove NOPSAM to email me. Please let
me know if you have posted also.
Follow the other good instructions others have given here but if you are
not absolutely sure which breaker to buy you could take the old one to the
electrical supply house and make sure you get the right one.
If you can't have the main power turned off that long then wire nut the end
of the wire you disconnected and tape it out of the way where it cannot
touch anything and turn the main back on. Be sure to remember to turn it
back off when you return. If there is even the SLIGHTEST chance of someone
else touching anything while you are gone--let's make this a mandatory
thing if you have kids--then put the cover back on temporarily. If no one
is home or if they can be trusted to keep fingers out then you can leave it
the joy of paying an electrician is that he can spot other problems
which may have happened since the service was new and point out safety
upgrades available including newer types of safety breakers available
to protect your home.
the joy of doing itself is not lost when you have a CPR professional
next to you to revive you if you slip.
"AFCIs are already recognized for their effectiveness in preventing
fires. The most recent edition of the National Electrical Code, the
widely-adopted model code for electrical wiring, will require AFCIs for
bedroom circuits in new residential construction, effective January
see full story at:
please see also basic info at:
This sounds like a real meter to me, but if it's not, it's worth
buying one. $20 dollars would be enough, and it will last for
decades. If you have is a neon light with a couple wires, you can get
by with that in this case, but if it is the model with just two 3-inch
leads, that's really too short when you want your hands to be free and
to hold the test probes 3 inches from the wires your touching and to
hold your hands away from everything. Especially when things are
Before I turned the power off, I would verify that the meter worked
but stuffing one probe in each slot of a regular receptacle. Should
say 110 to 120 volts AC,
Eventually, after I became confident, which may not be this week, I
would also test at the output screw of the suppposedly bad breaker to
make sure it is actually dead there too. And I would test the breaker
to it, to make sure the meter is working (meaning I wouldn't have had
to do it in the previous paragraph.)
The reasons for these extra tests is that some day, once you're more
confident, you'll assume the wrong thing is bad, and you'll run around
in circles, replacing the wrong thing only to have the system still
not work. Then you'll have to put things partly back togeher and do
these tests, so it pays to make more tests in the first place. But
this time, you've probably got it right.
Then I would turn everything off. I use a flashlight that takes C
size batteries, fits in my mouth and points where I am looking. there
are those that strap to one's head too, and I have one, but haven't
used it for more than 10 minutes so far.
I've added one circuit breaker and replaced another. I just bought,
in advance, the one they sold the most of at the store**, that was the
same width as the one in my box with the cover on. If I had gotten
the wrong one, I would have just left things unfinished and gone to
buy the right one. Of course I live alone, so no one needs
electricity when I'm not there. But, I got the right one each time.
If there were only two choices you could buy both and return one.
**This assumes the store is somwhere near you. They sell different
things in the suburbs for example from what they sell in Brooklyn
hardware stores. Because the housing is newer in the suburbs on
Remove NOPSAM to email me. Please let
me know if you have posted also.
Thanks for all the replies. Nexus 7 gave me some good detailed info on how
a. I understand this can be a significant endeavor for a newbie. That's
why I had the common sense to inquire about it first. I do appreciate the
words of caution some of you wrote. That's why I wrote, to see how far
fetched I might be.
b. My multi-meter is a $20 from Sears and Roebuck. It tests various
voltages, resistance etc., with a digital readout. I've used it on 110 volt
lines prior to replacing light bulb sockets in my house. It is not a simple
"circuit tester" i.e. a light is either on or off if electricity is flowing
through but one that measures volts, ohms, etc.
c. I do test, carefully, before shutting off power to the particular
circuit (in past times it was the wires at the socket, not a circuit
breaker) to determine if it is live and then dead after I thought I turned
off the circuit. I.e. did I really get the juice to that particular socket
off, before starting.
d. Info re: neutral and ground wires most helpful. It is a 110 voltage
circuit, not 220 (I wouldn't even consider doing anything to a 220). I
understand that the street side of the power supply will always be hot even
after switching main breaker off. The breaker I need to replace is about as
remote from that main breaker can be in the box. If I recall from when I
watched an electrician add a 220 volt circuit to my box, the "main breaker"
and therefore the street side supply is under a separate portion of the box
that would require an additional cover be removed to even get into the guts
of those wires. I.e. one would have to take an extra uncovering procedure
to get to where the always hot lines on the street side are.
e. Thanks for info that the breaker may snap out rather than unscrew. I
didn't know that.
f. I had no idea that circuit breakers might be so specific i.e. they
aren't all alike. If/when I embark on this, I now know that I can't just
put any breaker in. In my case, probably best to take old one in so someone
with expertise can be certain the replacement matches the old one rather
than my making that judgment. Thanks for info on this.
g. Had to chuckle about having a neighbor standby for potential
resuscitation. I had already decided I wouldn't do this when no one else
was around, figuring that if I did get zapped, someone might call 911.
Sounds silly, but I do think that way!!
h. Because you guys nicely answered items that I was concerned about and
because I think I understand what you're talking about, I think I will
proceed. This is in a second home, not being used much this winter, so I'll
do this some time next week. I will reassess, after removing the cover of
the box before continuing on, just to be sure it isn't more of a maze than
I read the article on AFCI breakers. It sounds like a good idea. The
breaker I'm replacing is about 25 yrs old (original with construction of the
house) and I doubt it is an AFCI. Is replacing the old one with an AFCI out
of the question? You all stated that the replacement breaker must match the
ones already installed in the breaker box and I suspect they all where made
prior to the use of AFCI's.
The new breaker doesn't have to match the ones in there, but it has to
be made to work with the box you have. It might look different that the
25 y.o. ones you have in there. Given that the box is not too new, your
first headache is to find breakers that are made for it. If you do, and
you find you have a choice of regular, GFCI, and AFCI types, then you
can address that choice. I can't advise you about AFCIs, but I'm trying
to say you might be jumping the gun there.
By "made for it" or "it has to be made to work with the box you have" do you
mean "fits into it? If I get one that fits, then sub-select on AFCI, GFCI,
etc. When people said the breaker must be made for my box, I thought maybe
it meant thinks like copper wire vs. aluminum wire (if that's still used)
vs. type of contact, etc. So in speaking of getting a proper one for my
circuit box are we simply talking about one that is of same size, type of
connection and amp rating?
Thanks again. I don't mean to be beating a dead horse, honest.
I wouldn't be comfortable if I had one that happens to fit in the box,
as opposed to one made specifically for it, or listed as an
interchangeable part. For example, there are QO type breakers made by
manufacturers other than SquareD that will work with a SquareD QO box.
And although I haven't seen any, there might be some that will snap on
to a QO box, but are not listed as compatible with that box. This I
would avoid. Unless you cannot do so at all, use one specified to work
in your box. You may have to go to an electrical supply store, rather
than the big box stores.
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