Bare ground touching neutral

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hacim23

hacim23

Journeyman Electrician
Location
washington, DC
Occupation
Electrician
If your bare equipment ground is making contact with the neutral what will happen? This happens to be in a switchboard disconnect where they are bonded a few feet away but I noticed they are also touching inside the cabinet. Is this a problem? Thanks
 
hacim23 said:
If your bare equipment ground is making contact with the neutral what will happen? This happens to be in a switchboard disconnect where they are bonded a few feet away but I noticed they are also touching inside the cabinet. Is this a problem? Thanks
Click to expand...

The world as we know it will end!

The bare EG will carry a portion of the neutral load. How much of a problem is hard to tell from here.

I would have moved the EG over and gone on with the day
 
If this is not a main switch gear and the equipment grounding conductor touches the neutral then current will travel thru the equipment grounding conductor as well as the neutral. This is not compliant and potential dangerous but the circuit will work just fine
 
Dennis Alwon said:
If this is not a main switch gear and the equipment grounding conductor touches the neutral then current will travel thru the equipment grounding conductor as well as the neutral. This is not compliant and potential dangerous but the circuit will work just fine
Click to expand...

Out of curiosity I wanted to bend your ear. I did a neutral load calculation using multiple circuits a few years back. Had 5 incandescents pulling load on separate circuits using separate 14/2. During this “experiment I terminated the neutrals from all circuits (same phase) into and out of a small buss sitting on a resistive rubber mat. After the unbalanced load reached the buss and tied into the other neutrals, the entire load went through only one neutral instead of all. Not seeing how the contact between the EGC and the Grounded Conductor would split between the two, as you stated above. Mine found the most direct route with the least impedence and combined into it. Please educate me. Thanks
 
191021-0836 EDT

WilliamSmithEES:

I don't quite understand your comment. I don't see how your experiment relates, or I misunderstand your experiment.

The purpose and philosophy of the EGC is that under normal operating conditions it carries no load current. This means anywhere along its path back to the point where it is required to terminate with the supply neutral and earthing conductor. This point is the one and only point where the EGC and neutral bus barsm and earth are connected together.

All conductive equipment cabinets (a drill motor housing is a cabinet for my purposes here) are connected to the EGC. If there is no current or very little flowing on the EGC anywhere, then its potential at all places along the EGC and things connected to the EGC is near that of earth, and things like water pipes. This generally reduces shock hazards for low leakage currents to the EGC connected components.

However, a dead short from a hot line to the EGC at some point may produce a shock potential at that point relative to earth of approximately 1/2 the potential of the hot line. You can analyze why.

.
 
William (Journeyman Electician?):

Experiments usually produce numbers. These can be shared so everyone can see exactly what happened to help you analyze your conclusion.

You said they were from multiple circuits. If they were from opposite sides of the 120/240 (assumed) service, those loads may cancel out with only the unbalanced current looking for a neutral. The rest stays on ungrounded conductors.
 
I would bet there is some current on all the wires but perhaps very small amounts. Obviously the current will travel thru the one with the least impedance but some will go other places.
 
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