question from a total novice.

[dapperdan7]

hi guys im new here.just a quick one.i want to replace a lightswitch in the bathroom.is finding the breaker/fuse that runs that switch all i need to do in terms of safety?

thanx much.

dan

[Snoonyb]

Pretty much.

[HayZee518]

the bathroom lighting may be on its own circuit or be fed from another lighting circuit. if it is inside a two gang box that also houses an outlet (gfci) the gfci may be on its own breaker if the guy that put it in was following the dedicated requirement. don't just assume that because this switch is in the bathroom, that switching off the bathroom breaker is gonna kill this circuit. look for any/all possibilities AND when you are absolutely positive that there is no current on the switch and adjacent conductors should you even attempt a repair.

[dapperdan7]

there is also an outlet right next to the switch.can i just shut down all the circuit breakers for before i do the repair?how can i test if a circuit is still live or not without frying myself?

thanx for any help.

[Jimmer]

You can pick up an inexpensive tester at any hardware store, or you can use a multimeter. If you pick up an induction tester, note that you can get false current detection if the wire you are testing is running next to another wire that has current flowing through it

[dapperdan7]

so will a multimeter work better?and what is the process of testing a circuit using a multimeter?

[Jimmer]

If it is has various setting, set the multimeter to AC 120 range ,if it is autoranging then just set it to AC and insert the leads into the outlet, red into the larger and black into the smaller. Or test red in one of the slots while holding the black in the ground hole, then check the other slot to the ground. Sometimes homeowners who don't know will put the hot to the neutral side (called reverse polarity) Get into the habit of checking both plugs in a duplex outlet. Most are split on two circuits in the kitchen and may be split or independantly switched in livingrooms.

[HayZee518]

easier way --- find the breaker that shuts off the light - shut it off and leave it off - ok so far, then plug a small desk lamp into the gfci. if its out then there's no power there - if there is - start shutting off breakers again.

[dapperdan7]

thanx hayzee.that did the job right!

[scorrpio]

Some pointers:
1. Get a basic multimeter that can test for AC, DC voltage and resistance. I still use a $20 meter I bought 13 years ago at RadioShack.

2. Never trust circuit breaker labels. You never know who'se been at those wires since original install.

3. No helper? Sound is your friend. Plug something noisy - like a hair dryer - into the outlet, and go play with breakers in the panel.

4. Once you open a box, and see the contacts, use insulated pliers to touch each wire to metal of the box before handling that wire. You never know if a box also serves as another circuit junction.

5. To splice wires inside a box, use wire nuts. Buy a whole jar of those rated for up to four 12 AWG. They are a lot better than tape.