Ground versus Neutral wiring

Old 02-28-03, 09:14 AM
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Ground versus Neutral wiring

We had some strange fluctations in voltage in our home,and called an electrician to come check it out.After about an hour of checking connections and tightening wires,he said we had lost our neutral .
He went to the meter base,where we have a 200 amp disconnect,and he said our "neutral wire" was too small. It is a #6 solid copper wire that was run when power was setup in our home.We have a mobile home by the way.
He said the wire could be broken or it could be not coming from power company.
We called the power company and they checked the voltage at our meter,and they too said our wire was broken or burned.They said it should be #4-0 or 2-0.
I dont uinderstand difference between neutral and ground,and if no current goes thru neutral wire,why should it be as big as supply lines?
I need help,before I go buy new wire and install it.
Old 02-28-03, 10:31 AM
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Ground and neutral are different and it is a current carrying conductor. 2/0 would be fine and someone that installed the service goofed up. I cant believe it passed inspection or that the poco hooked it up like that. This would take a bit of explaining to clear of the differences between the 2 here and it is an area of misunderstanding and believe it or not I have seen electricians that didnt seem to have a great grip on the difference or how it worked. Maybe some one here as a good in the box explanation. But you need to fix it and might consider having the electrician do that, it could be dangerous.
Old 02-28-03, 11:08 AM
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As sberry said, the neutral carries a lot of current. Although it is possible for the neutral to carry just as much current as the hot wires, it usually carries less and thus it is allowed to be somewhat smaller than the hot wires.

You need to get this repaired ASAP. Otherwise, you will cause permanent damage to the appliances in your home. Your appliances are getting more or less than the 120 volts they want, and this is very hard on them.
Old 02-28-03, 01:27 PM
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The neutral carries the unbalanced load between the phase connectors. For instance if Phase "A" is carrying 75 Amps and Phase B is carrying 60 Amps, the neutral will be carrying 15 Amps. Normally, with slight deviance, your 240 volt loads are evenly balanced (i.e. heating elements connected across both phases create an equal load on each phase). Your 6 guage wire is more than adequate (although non code compliant) to carry the load if your system is evenly balanced. You must have all of your major 120 volt loads on the same phase to create such an inbalance. The more likely cause of your problem was a loose connection on your neutral with the ensuing arcing and overheating damaging your neutral. Of course, if your system was indeed out of balance to the tune of greater than 50-60 amps, then your neutral would eventually break down from being overheated because there is not any overcurrent protection on your neutral. That is why it is a good idea to size your neutral to the largest phase conductor (the code allows you to drop down a size on a service) so there would be no way to overload your neutral wire.

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