bathroom lighting dillema

[mybrainhurts]

I have a bit of a dillema with my bathroom lighting. I am trying to install a new light above the mirror but i just can't seem to get it to hook up properly. The existing light worked and I was positive I saw what was already hooked up and did the same with the new light. I have black to black and white to white, but still nothing works. The concern that I have, and which is more than likely the case, is that I am attaching the wrong wires. There are three sets of black and white wires comig out from the back of the lighting panel. If you picture the octagonal box facing you there are to sets of wires on the far left (which is closest to the wall with the light switch) one above the other, and then the last set of black and white wires are located down towards the bottom right corner of the oct. box. THe white wire from the bottom right one is left open whereas the other white wires have been merretted together. My problem lies with the black wires. Since there are three of them exposed I have tried connecting the black wire from the new light to each one of them and still no luck with power. I hope I have explained everything ok, if not I will try to give as much clarification as possible if anyone is willing to help.

=) cheers

[RBM]

If this is the only light that goes on with the switch, what you have in the box are one feed, bringing in the 120? volts, one line bringing the 120? volts out to something else, and one cable which goes to your switch. Once you determine which is which, you should have two white wires together which will also connect to the white of your fixture. You'll have two blacks together to which you will also attach the white wire to your switch and wirenut the three. You are left with one black, which is the return wire from the switch and this will go to the black of your fixture.

[mybrainhurts]

hmmm, I understand your explanation regarding the wires I am just wondering how I can determine which are for which. Beside the light switch on the same wall there is also a plug, would this account for one of the sets of wires as well?

Also, is there any guaranteed way of ensuring the wires stay connected? By this I mean is there any product out there that will ensure a more secure conenction between the wires that you are using. THe reason for my question is that merrets (wire connectors) just seem to be so darn tempermental. Just when you think you've got the wires secured together you go and try and tuck them away and one wire pops out.

In the response you gave it seems like I will definitely be connecting two or more copper wires together, using a bigger wire connector (merrett) would definitely be the better way to go then eh?

thanks for your help so far.

cheers

[Rich Greenberg]

Here is my best guess:

The 3 b/w pairs are:

1) Supply from the breaker. 2) The switch. 3) feed to some other light or fan.

Seperate all wires. See if one pair has 110vac on it. Thats #1.

If the other 2 pairs have zero voltage between then and to ground, then use an ohmmeter (or continuity tester). If one goes from zero ohms to infinite ohms with flipping the switch, Thats #2.

If the third pair has continuity independant of the switch and is some value greater than zero ohms, thats (probably) #3.

Turn the breaker off. Connect the #1 & #3 pairs together, black to black and white to white. Turn the breaker on. Is another light or a fan now on? If yes, your rolling. Turn the breaker off again.

Disconnect the temporary connection between #1 & #3. Connect #3 to the light fixture matching colors.

Connect the white wire of #1 to the white of the fixture & #3.

Connect the black wire of #1 to the black of #2.

Connect the white of #2 to the black of the fixture & #3.

Check the wireing, turn switch off. Turn breaker on. If my guesses are correct and you did it right all should work.

If it turns out that you did NOT want whatever is on #3 to be controlled by the switch but on always (perhaps it has its own switch), move the black & white of #3 from the b/w of the fixture to the b/w of #1.

Put everything back together and clean up.

NOTE: If you are not comfortable doing the tests and connections I have described, CALL AN ELECTRICIAN.

[mybrainhurts]

I have taken a picture of the box and the wires in the hopes that some clarification will arise regarding my dillema. Thanks for your detailed description regarding some steps I should take. I will give them a shot and see how they turn out. But let me know if the picture makes any thing clearer.

thanks

[e-mail]/images/pic1.jpg

cheers

[HeyBub]

Think voltmeter.

[Mikepier]

The link to the pictures did not work. But one thing that I do not think was mentioned, if you have GFI outlet in your bathroom, see if you have to reset it.

[Don Klipstein]

There are now 9 combinations to try, and it is still possible to overload a white wire somewhere in your house if you use a white wire other than the one associated with the proper black wire (assuming more than one white wire works).

If any wires are of color other than what is usually used (sometimes indicating a hot-neutral reverse - I do see this sometimes), it gets even more complicated. You will need a multimeter to identify hot, grounded (neutral), and not-connected-to-anything wires. Hot wires have close to

120V with respect to ground. Neutral wires have no voltage with respect to ground, except can have a little if current from something else flows through a part of that circuit. Neutral wires have close to 120V with respect to hot wires. Wires not connected to anything ideally have no voltage with respect to either hot wires or ground, although you usually get some low voltage readings with respect to hot, ground, or both.

Anyone else doing such a job in the future, when seeing wires going nowhere of same color as wires being disconnected, should put tape or some other marking on the wires that were used.

===================

Is the new fixture fluorescent? If so, you need a ground wire going to the green wire in the fixture or to the metal fixture frame. Using the neutral for this will work but feels to me like a code violation and probably increases the risk of a shock hazard from wire or connection failures. Fluorescent bulbs trying to start can have the electric field distribution within the bulbs affected by grounding of the fixture. This sometimes (not always) affects starting of fluorescents. - Don Klipstein ( [e-mail])

[Don Klipstein]

Try wirenuts of a different size. They come in different sizes and should have ratings as to how many wires of what size.

You may have to straighten and retwist wires. Retwist them with pliers. Twist them in the same direction that the wirenut rotates when putting on the wirenut. You may need to gain experience as to how tightly to put on a wirenut. Get a few spare wirenuts and a few feetb of Romes of same wire size to practice on if you are new to this.

I have at a few times found wire ends screwed up beyond usefulness, and then had to cut the wires and strip them to expose fresh wire ends to twist.

Also, it is a good idea to use electrical tape to tape on the wirenuts once they are on. Wind on at least a couple layers of tape around both the wirenut and the wires being capped. This helps the wirenut not get dislodged by bending of the wires afterwards or by shock/vibration.

- Don Klipstein ( [e-mail])

[mybrainhurts]

i do have gfi outlet and I will try and do the whole reset thing. In regards to the link to the picture you have to click the little blue line before the @rogers.com part because it is protecting my email addy from spammers and stuff.

cheers

[mybrainhurts]

i just went and checked the GFI plug and nothing was tripped. I guess since it is 12:30am I will head to bed and have to go out and buy a voltmeter tomorrow and try and get this all figured out.

[mybrainhurts]

I just wanted to say thanks to everyone for their input and assistance. I got myself the digital multi meter, found out what was what, and hooked everything up properly. And voila...let there be light!!

Thanks again

[nospambob]