Latest Discussions : Electrical & Lighting

northerndesign

01:38PM | 09/21/07
Member Since: 09/20/07
2 lifetime posts
I own a old aparment building. The hallway and exterior lights are on a timer that no longer works. We cannot identify which wire is which on the old cloth wiring. Strangely there are three wires that are all identical. How do I tell what is what?

Billhart

02:43PM | 09/21/07
Member Since: 04/25/05
1915 lifetime posts
"Strangely there are three wires that are all identical."

Where are these at? The timer, The lights?

What was there before and what connected to what?

What kind of test equipment do you have?

northerndesign

04:00PM | 09/21/07
Member Since: 09/20/07
2 lifetime posts
I would have tagged the wires as I disconnected them from the timer. However my boyfriend did not. They are coming out of the junction box. He said he tried using a standard wire tester but he still could not figure it out.

Billhart

08:46PM | 09/21/07
Member Since: 04/25/05
1915 lifetime posts
I am SPECULATING that what you have is something like this.

http://www.selfhelpandmore.com/switchoutlet/fixonhotswitch/

Except for some Unswitched power onward.

You have a neutral and always hot to operate the timer.

And the 3 wire is the switched hot.

" a standard wire tester"

There is no such thing. They range from digital voltmeters with $1.79 neon testers with several in between.

And each on has there only advantages and disavantages.

ultramegabob

05:24AM | 10/28/07
Member Since: 08/27/07
23 lifetime posts
from what i have to go on, first remove lightbulbs from whatever fixture you are turning on to prevent backfed power on the neutral.

use a volt meter and check for voltage between two of the three wires, these are your power coming in, and the third wire should be your switchleg out to your fixture.

now find a known neutral by either streatching out an extension cord from a recepticle that you know is properly wired or run a piece of wire all the way to the neutral buss in the electrical panel, now you can identify which of the two are power, and you can check for continuity on the neutral. if this doesnt make sense hire an electrician...


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