Home wiring question Additional info 8/10

[Limited-Time]

I have a florescent light fixture controlled by 2 switches (3 way?) However even with the switch/switches in the off position the lines measure about 50 volts. What/where should I start looking, switches or the actual wiring it's self?

 

[Mntom]

Re: Home wiring question

Re: Home wiring question

The way the switches work they are supposed to be either 'on' or 'off' with no in between. One of the two switches has gone to crap.

 

[joed]

Re: Home wiring question

Re: Home wiring question

Does the light go on and off with the switches? If it does then everything is fine.
If you are measuring with a digital meter there may not actually be any voltage there. It's called phantom voltage.

 

[Tim Frank]

Re: Home wiring question

Re: Home wiring question

Where are you measuring the voltage?

 

[DianneB]

Re: Home wiring question

Re: Home wiring question

Check between ground (the bare wire) and Neutral (white wire) on the fixture - there should be ZERO volts - if you have anything else, the wiring is screwed up.

Hot wire (Black on the fixture) should be 115 (approx) when the light is on and ZERO when the light is off - if you have anything else, call an electrician because the wiring is screwed up and your don't want to shock somebody or cause a fire.

 

[Limited-Time]

Re: Home wiring question

Re: Home wiring question

Where are you measuring the voltage?

Across the hot and neutral.

Does the light go on and off with the switches? If it does then everything is fine.
If you are measuring with a digital meter there may not actually be any voltage there. It's called phantom voltage.

And yes using a digital volt meter.

 

[rbh]

Re: Home wiring question

Re: Home wiring question

UUHHMMM, just trying to remember??????
OH, is there not a reversle of ground and neutral when you do multi switches???

 

[Tim Frank]

Re: Home wiring question

Re: Home wiring question

Across the hot and neutral.



And yes using a digital volt meter.

Bit more info would help and it is near-impossible to assess someone's experience in a forum such as this, so no offense if I suggest something that you feel is trivial...

Why were you testing this? Was there a problem.'
Was the test across a black and white wire or are you certain you had a hot and the neutral?

Do make sure that you have zero volts between neutral and ground.

 

[Tim Frank]

Re: Home wiring question

Re: Home wiring question

UUHHMMM, just trying to remember??????
OH, is there not a reversle of ground and neutral when you do multi switches???

Ground and neutral should have same potential.

 

[rbh]

Re: Home wiring question

Re: Home wiring question

Ground and neutral should have same potential.

Yes, but it is the multi switches were you have to reverse something??? so that each switch will turn the light off and on (it has been a few years)
OK, who's got the diagram??

 

[DennisM]

Re: Home wiring question

Re: Home wiring question

Also in a three way switch configuration there will be a hot running from switch to switch always if i remember correctly

 

[j_martin]

Re: Home wiring question

Re: Home wiring question

In a 3 way switch setup, you basically select between two conductors for the hot wire. If both switches are on the wire, current flows, light lights, voltage 115. If not, then current doesn't flow, light off, voltage 0.

When the light is on, the other conductor is floating unconnected and running parallel to the energized wire. It would be natural for it to have some small, inconsequential capacitive coupled voltage on it.

hope it helps
John

 

[bruceb58]

Re: Home wiring question

Re: Home wiring question

Yes, but it is the multi switches were you have to reverse something??? so that each switch will turn the light off and on (it has been a few years)
OK, who's got the diagram??

No.

You never switch grounds or neutral.

Basically a 3 way switch is a single pole double throw switch. The two switches are wired up so that the double throws are wired to the double throws on trhe other switch. The hot is connected to the common of one switch and the load is connected to the commom of the load.

 

[rbh]

Re: Home wiring question

Re: Home wiring question

No.

You never switch grounds or neutral.

Basically a 3 way switch is a single pole double throw switch. The two switches are wired up so that the double throws are wired to the double throws on trhe other switch. The hot is connected to the common of one switch and the load is connected to the commom of the load.

Do you have the diagram some place???
I would like to see how it is done as it has been a quite a few years since I learned this stuff.

 

[Rscardina]

Re: Home wiring question

Re: Home wiring question

Bruce is correct on this one, however, in residential applications the original installer may have used romex to make the two connections. if he didnt run a three wire (black , red, white ) then the he may have used the White on a 2 wire application to actually power.

Can't comment any further without knowing the wiring setup they used.

This is very common on hack jobs I've seen...and any inspector would catch this and hold them to NEC.

 

[Limited-Time]

Re: Home wiring question

Re: Home wiring question

Bit more info would help and it is near-impossible to assess someone's experience in a forum such as this, so no offense if I suggest something that you feel is trivial...

Why were you testing this? Was there a problem.'
Was the test across a black and white wire or are you certain you had a hot and the neutral?

Do make sure that you have zero volts between neutral and ground.

No offense taken. A little back ground info. sometime yesterday AM the light fixture in my kitchen went crashing to the ground. The drywall anchors let loose (don't ask) the falling fixture pulled about 5 feet of wire through the box before it snapped off at the ballast. I grabbed a Digital Volt Meter (DMV) to see if the lines were hot before I started to handle them. That's when I got the 50v reading. I switched the first switch on and the reading went to 120v. Turned it off using the other switch and it still registered 50v. I want to make sure nothing is wrong before I CORRECTLY remount the new fixture.

 

[marlboro180]

Re: Home wiring question

Re: Home wiring question

Sounds like you have a bad switch, or the insulation on the romex may have been compromised during the fall. 50V is not normal in any way, might be leaking into the neutral/ ground side.

Did you check for resistance ( ohms) between hot and neutral, with the breaker and all other fixtures off?

 

[bruceb58]

Re: Home wiring question

Re: Home wiring question

Do you have the diagram some place???
I would like to see how it is done as it has been a quite a few years since I learned this stuff.

Here is one.

 

[levittownnick]

Re: Home wiring question

Re: Home wiring question

In a 3 way switch setup, you basically select between two conductors for the hot wire. If both switches are on the wire, current flows, light lights, voltage 115. If not, then current doesn't flow, light off, voltage 0.

When the light is on, the other conductor is floating unconnected and running parallel to the energized wire. It would be natural for it to have some small, inconsequential capacitive coupled voltage on it.

hope it helps
John

The above quote is right on. You don't have a problem. Time to go boating/fishing. Have fun.
Nick

 

[rbh]

Re: Home wiring question

Re: Home wiring question

Thanks Bruce.
Still get this stuff mixed up as I do tel cabling for the most part, and have not done this stuff since the labs in school.
And worse yet

series parallel
parallel series
UGH