I have a 3-wire cable. One wire is sheathed in green insulation – obviously the ground. The other 2 wires are insulated by the cable material but do not have their own colored insulation.
I need to find out which wire is hot and which one is the neutral.
Can anyone tell me how, using an electrical tester, to determine which wire is hot?
Thanks,
dlb
.
Replies
dlb,
Test between the green wire and each unmarked one, should get a reading on the hot, not the neutral. I have a meter that you can touch to a hot and get a reading, greenlee(sp). If your ground is no good, don't expect a reading. If that is the case find something that is grounded, and check between that and the unmarked wires.
Northeastvt
Is there some kind of molded rib or line on the sheathing that would indicate the hot wire?
"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Nope. TThere is not one marking on the wire as to which is neutral and which is hot. It is a ribbed rubber-like material cable which acts as the insulation for the hot and neutral wire an the ground has it's own green insulation.
I appreciate the advice and will give (some) of the test methods a try. I do not plan on touching anything w/ my fingers, meter or wire. "I only have one life to live", someone famous once said and I don't plan on dying over a dishwasher installation!
Thanks again,
dlb
.
The undisciplined life is not worth examining.
I did not mean a marking on the wire, I meant a marking on the rubber jacket. You say it is ribbed ... does the ribbing cover the entire jacket, or is it only over one wire? Otherwise I agree about the pencil-style circuit tester. I have one that I use to check for hot outlets, and it is sensitive enough that it works better on one side of a romex than the other. Like this from GB, found it at Lowes...
Circuit Alertâ„¢ Non-Contact Voltage DetectorIndicates the presence of AC Voltage from 50 - 600 V.
View Image
"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Edited 11/12/2007 8:13 am ET by FastEddie
maybe I'm still asleep but it sounds like he's trying to hook the thing up ..
.
.
., wer ist jetzt der Idiot ?
I like the Fluke a lot better. Only a couple of bucks more. I tried Greenlee and GB and there was something I did not really carte for about both.
I picked up a Fluke solenoid style meter and the "sniffer" non-contact for about $40.
The wire in question may be some that has just discolored and it is impossible to distinguish the black from white.
I've got that one, and I like it. I also keep losing it.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.
Are the wires solid copper or made up of many strands twisted together, like lamp cord?This sounds like someone wired the circuit with heavy duty grounded appliance line cord.
BruceT
The cable contains 3 wires, one of which is independently insulated w/in the cable itself - that being the ground.
The other 2 wires, stranded not solid, are insulated by the cable rubber-like material. There is no independent insulation for the hot and neutral.
Now, the house is 50+ yrs old. I am trying, or did, hook up a dishwasher. I put one lead of my tester on the ground and the other lead on right wire. I got a 32 volt reading. I did the same for the left wire and got a 0 volt reading. Naturally, with a lead touching each of the 2 wires I got 120 volts.
Deduction: the wire w/ voltage was the hot and the other one the neutral. I hooked it up that way and it ran.
Thanks for all of the advice,
dlb
.
The undisciplined life is not worth examining.
"I am trying, or did, hook up a dishwasher."Ahh, now it makes sense. The cable you have been describing is a grounded appliance line cord. If you trace it back to the other end you should find it plugged into an outlet, probably under the sink. The fact that you are seeing only 32V to the ground wire indicates that it is plugged into a non-grounded receptacle or one with a faulty ground connection. Even in the 50's I think kitchen outlets were supposed to be grounded, but I'm not sure of that.Congratulations on the successful installation. Now I would recommend that you check out the outlet circuits in your kitchen and bathrooms to make sure that they are grounded. Are they two-prong or three? If they are three prong, put one voltage tester probe in the right hand slot and the other in the ground slot. If you don't have 115 volts or more they should be fixed. If they are two-prong, it would be a good idea to have a qualified person replace them with grounded ones and while he's at it, it would be a good idea to put in GFCI outlets as needed.
BruceT
" The cable you have been describing is a grounded appliance line cord. "
You learn something new every day. I do appreciate the reply. I sort of suspect that the entire electrical system is not grounded even though the outlets are 3 prong. I have not verified that assumption yet.
"If they are three prong, put one voltage tester probe in the right hand slot and the other in the ground slot. If you don't have 115 volts or more they should be fixed."
Good idea. I will do that.
Thanks for the reply as it was very instructive,
dlb
.
The undisciplined life is not worth examining.
Man o man Bruce... I wouldn't be giving out that advice. I can think of several ways in which he could get bit good trying that, although I'm well aware of your reasoning. "First, Do no harm" ;)
PaulB
"I can think of several ways in which he could get bit good trying that..."You can? How? I've done it for 30 years, but if there is danger being a "capacitive ground" for a device that passes about as much power as a flashlight, I'll quit doing it.BruceT
If you have a "non-contact" type tester, which are normally mostly plastic and give a light and a beep-beep-beep around the hot wire, place the sensor tip next to each of the exposed wires. It will indicate which is the hot wire, vs. the others which will be neutral, ground, or just disconnected.
If you have to buy one of these testers, they cost about $10.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
If your hair looks funny, it's because God likes to scratch his nuts. You nut, you.
Run a voltage check between each of the three wires and a known ground. I've never seen cable like this, so who knows how it's tied in. Don't depend on the green being ground. The other two wires could BOTH be hot if it's 240.
Mike Hennessy
Pittsburgh, PA