We have a box with three light switches. The lights work, but they are wired improperly: Two of the switches will only work in tandem: Either both on or both off. The third switch is a second control for a hall light. The other control is a dimmer, but it doesn’t dim. The light goes on full strength.
We also have a bunch of mystery wires. The aforementioned box has wires that don’t touch the switches. Two other rooms have boxes with mystery wires, and a switch that is wired but not live.
For now, my husband just wants to rewire the light switches correctly. I am supposed to buy a voltmeter for the purpose. But, is a voltmeter like a multimeter with limited function? I am wondering what to buy to get the voltmeter function, and the capability to trace mystery wires.
Janet
P.S.
If it’s to be a multimeter, what specs should I be looking for?
Replies
Me thinks ya need to go to the library and read a bit first.
A good place to start is a full understanding of maxwell's equations.
well ok, ohms law would at least be a start.....
BTW, I typically still just check 120 Vac with my fingertips, but a novice should not try that.
A good place to start is a full understanding of maxwell's equations.
I don't think even Maxwell understood his effin' equations.
Based on your description of the problem, and your approach to solving it, I think you'd be best to get an electrician involved. A little knowledge can be a very dangerous thing.
Be safe.
As far as meters goes, about any multimeter will work for what you want to do. I'd buy one of the harbor freight cheapies myself, sometimes they are only $3.00. They are handy for testing things around the house, including batteries. I have two Harbor freight stores within 20 minutes from home, so I buy a few things from them.
Better... http://www.harborfreight.com/7-function-digital-multimeter-92020.html
Good.. http://www.harborfreight.com/7-function-digital-multimeter-90899.html
You need to understand what the meter is telling you though.
By the way, I usually use a "wiggy", which is a solenoid indicator, or a test light. A meter is not normally necessary for testing wiring..
The mystery wires are probably just electrical junctions for other circuits, which is why electrical boxes are also called junction boxes.
"The mystery wires are
"The mystery wires are probably just electrical junctions for other circuits, which is why electrical boxes are also called junction boxes."
Is that like being in a local subway station, where you can see tracks with no platforms near them? The express trains go through the station even though they never stop there, and nobody could get to them if they did. They're just taking advantage of same tunnel.
Bazactly!
It's exactly what happens sometimes.
Yeah, I'd suggest a "wiggy"
Yeah, I'd suggest a "wiggy" for starters (since too many DIYers tend to misinterpret multimeter readings), and then you can get one of several circuit tracers depending on the type of tracing you want to do.
The Christmas tree light checker type tester is fairly good for roughly checking which wires are hot and which not (though you should never bet your life on what it says). There are tracers where you plug one end into a (hot) outlet and you can then follow the circuit through the walls and back to the breaker panel. There are tracers that allow you to put a "tone" on an individual (non-hot) wire and determine where it comes out on the other end.
But most sparkies have relatively little need for any of those tracers -- a simple continuity tester (either a "buzzer" or an ohmeter function on a multimeter) combined with a little insight will identify 95% of the "mystery" wires.
If you get a multimeter, the specs hardly matter. Just about any meter sold will do 250VAC, which is the only scale you really need, plus the ohmeter scale. I prefer a needle-type meter, though a digital is OK if it has a read-and-hold feature. And it's nice to have a meter with an audible continuity checker.
Three things to get
If you're going to do this, a multimeter is not the thing to start with. What you need in order of importance and use are:
1. A good basic book on house wiring. I don't know one, but somebody else here may have a recommendation. There's a substantial learning curve before you can do this safely. Read everything before you do anything.
2. One of those non-contact beep and light testers. Greenlee makes a good one. I never touch anything until the Greenlee confirms that I've found and killed all the breakers/fuses involved.
3. Instead of a common multimeter, get one that has the clamp-around ammeter function in addition to volts and ohms. Fluke is a good make. They also tend to be more rugged than the electronics guys' bench type meters.
Be aware that if the wiring is screwed up in one box, it's probably also screwed up in other boxes. It's possible that somebody cross-connected two circuits, so turning off one breaker won't be enough. You have to turn them both off, and try to find the cross connection. There may also be hidden boxes. It's illegal to do that, but it happens a lot. With electrical stuff, the screwup and the symptoms are often in different places.
Since you're doing this yourselves, instead of trying to fix things piecemeal, it may be smarter to do an electrical tune-up on the whole house. Start early on a Saturday morning. Turn off all the breakers. Open all the boxes. Clean and check all the junctions. Replace any worn out switches and receptacles. Trace and label everything with circuit numbers as you turn them on one at a time. With electricity, finding a particular problem isn't necessarily easier than just going thru it all and making it all right.
-- J.S.
John
"With electricity, finding a particular problem isn't necessarily easier than just going thru it all and making it all right."
No joking there. Sometimes the hardest part is finding the breaker that turns off whatever it is you are working on.
Label, Label, Label!
well sure, anything can be done with the right tool.........
but dammit-an upgraded labeled panel is sure a big help.
Bull shit when you open a panel door and find not one stink'n thing written inside.
Can you tell how it burns me?
You leave a persons home and all the clocks are flashing, the program they were taping is interupted..............you've already pissed em off for the home office interuption.
What I put inside the panel is ...
A sheet of paper in a clear plastic protector. On it I drew a simple floor plan with the locations of all the boxes and their circuit numbers.
This is something that pretty much any homeowner can do, and save themselves some money when they call an electrician.
-- J.S.