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# 45 volt AC mystery...

#1
09-13-14, 03:55 PM
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Join Date: Oct 2012
Location: USA
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45 volt AC mystery...

Dear All,

I hope that one of you can solve the following '45 volt' mystery for me.

The image below shows the weird switch. Two red wires hooked up to the switch, two white wire-ends and two green wire-ends connected in the back of the box. When I set the switch one way, I measure 45 volts on the wires entering the switch; switched the other way I measure 0 volts.

I believe that the previous owners installed this switch to control outdoor lights (or something). The following image shows the wall on the outside:

The image below shows the location where I believe the wires end up (two white ones and a green one). However, I do not measure any voltage on these wires (all combinations, regardless of the switch position, yield 0 volt.

My intent is to remove the outside connections altogether and to replace the switch on the inside wall with a cover plate.

I have two questions: first: where's the 45 volts coming from? Second: is it safe to simply cap the red wires (one cap each) and stick them back in the box?

Hope you can help

Rene

#2
09-13-14, 04:10 PM
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Join Date: Mar 2006
Location: USA
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You are not doing the measurement correctly. You disconnect the two red wires and measure to neutral. One red wire to neutral should read ~120v the other ~0 volts. If you you measure with the neutrals twisted together you won''t need to figure out which neutral is line. Just measure each red to the twisted together neutrals.

#3
09-13-14, 04:46 PM
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How do we arrive at two red wires in a composition box where the switch is un-grounded

#4
09-13-14, 06:23 PM
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Join Date: Oct 2012
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Makes sense (although I'm still trying to understand the 45 volts). I did what you suggested and I find indeed the regular 110 between one of the red and a white one.

At least that part is solved, thanks; now I have to figure out where this stuff leads.
My guess is that since the switch seems to be 'in-line' on the red wire, that I can indeed simply remove the switch and 'cap off' the red wires, push them back in the box and put a cover plate on (equivalent to put the switch in a permanent 'off' position?)

R

#5
09-13-14, 06:32 PM
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Where is that mess of wires in picture 3 coming from? Is that how you found it? Are you removing it?

Just for suspenders-and-belt safety also separate the whites and cap.

#6
09-13-14, 07:24 PM
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How do we arrive at two red wires in a composition box where the switch is un-grounded
Good question. I am also wondering how we happen to have green insulated ground wires in that same composition box behind the cable clamp. NM cable doesn't have an insulated ground, but a bare ground. Either there is conduit running to the composition box (a code violation) or the individual wires are run open inside the wall (another code violation).

#7
09-14-14, 05:44 AM
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Measuring voltage between two switch terminals does not give useful information except to possibly point out a defective switch.

When the switch is "on" then voltage between the two switch terminals is always zero.

When the switch is "off" then voltage between the two switch terminals is unpredictable and depends on the nature of the load (things controlled by the switch and themselves turned on).

At first you can measure without disconnecting the wires from the switch. Supply (line) side terminal to neutral is always 120 volts. With the switch turned off load side terminal to neutral is zero, with the switch turned on load side terminal to neutral is 120 volts.

Supply side and load side cannot be described using words such as "left" or "bottom." It varies.

Last edited by AllanJ; 09-14-14 at 06:00 AM.
#8
09-14-14, 06:51 AM
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If you attempted to measure voltage between the two red wires you were un=sing an incorrect test procedure.

I too have concerns about the possible hidden code violations.

#9
09-14-14, 08:54 AM
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Join Date: Oct 2012
Location: USA
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Yep, the 'mess' is as I found it. I think that you all have it right; someone connected wires to provide power outdoors, but was unaware of the proper procedure.

Indeed, I'm going to try and take all this stuff out (hoping not to foul up the things which are working -- for instance, you (ray2047) suggest capping both whites separately. However, I don't know if something else in the house/room relies on those whites being connected?

#10
09-14-14, 09:37 AM
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However, I don't know if something else in the house/room relies on those whites being connected?
Unlikely but if that is true it is a code violation. What you have is power in and power out. No other reasonable explanation. Definitely do disconnect them and cap them. If you later find something doesn't work correct the wiring to it but leave those whites disconnected.