1/2 voltage


  #1  
Old 10-01-02, 05:46 PM
bobbrus
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1/2 voltage

I have a couple of curcuits that are puzzeling to me.

I have a 12-2 with ground in the basement that only has 1/2 voltage (about 60v) between ground and hot. When I traced it back to the breaker who ever installed it cut the ground in the box. Is it possible to get enough induced voltage between the common and the ground to get that level of reading with out a solid ground in the box (floating ground?)

I also have another old curcuit I went to put a new light in that only has about 60 volts. This is an older two wire curcuit so I am really stumped. I now know why the old light did not work, but not sure why I only have 60 volts on the line....any thoughts on how to troubelshoot?

Bob
 
  #2  
Old 10-01-02, 08:20 PM
A
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Loose or missing nuetral:

Check all connections, as well as (nuetral connections) as you work your way through the circuit in question. I would start in your breaker panel first, as you will then know that your source is good, wich will prevent you from spending time tracing the circuit through the house. You might also try checking any recent or latest upgrades or additions to the circuit in question.
Rehook the ground, then as you trace things down check the ground in every outlet, and switch, and rehook them as well.
 
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Old 10-01-02, 08:20 PM
J
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Whenever one or both of the two wires you measure voltage between is floating (i.e., not connected at either end), the voltage reading is meaningless. This is a well-known phenomenon called phantom voltage.

This is true for your ground wire that had been cut. It is also true for a switched hot wire with the switch in the off position.

A phantom voltage has no power behind it, and the voltage goes to zero immediately when presented with any load.
 
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Old 10-02-02, 03:59 PM
bwetzel
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A loose nuetral will cause the 60v reading. Since you stated that you only have 60v on more than one circuit, I would think the problem is in your panel. Look at the nuetral bar and see if there is any corrision. If so, turn off the main in the panel and remove the nuetral,cut and strip and replace.
 
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Old 10-04-02, 12:13 PM
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I'm wondering why the ground was cut. Was it intentional? Could this circuit have a ground fault and this was someone's way of "correcting" it?

I'd be very careful after reconnecting it and energizing this circuit. If the breaker trips immediately, you've got a connection between hot and ground.
 
 

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