Need some advice on some theory.

[tonyou812]

I went on a site visit today that was a proposed basement reno. While I was there talking with the Homeowner he told me that when he had his sump pump installed he had a problem with it and when the tech came out to check it out they found that there was current present in the water. If you put your hand in the water you could feel the electricity. And he was told that he needed an electrician to come an fix the problem.
So he called an ec and he said that the origional water bond was missing due to pex being installed, which broke the bond. So A new water bond was installed (#6, 100 amp service) and the problem went away.
I guess one could say that the problem was solved but it didnt satisfiy me. My feeling is that the water bond shouldnt be installed to acually do work but instead be there as a fail safe....I think that there is a more serious underlying problem and the ec only put a band aid on it. I put my amp meter on it and it only read 1.8 amps (granted there were no real loads on the house save for a few lights).When I pushed the float switch on the sump the reading jumped to 6.8 amps. I didnt spend a whole lot of time investigating due to the fact that I didnt have the job yet but I was curious anyway.
What do you guys think about it...? The service is an old Square DQO from the 70's. And the HO wasnt living there yet so there wasnt really a big load on the home.

 

[SG-1]

I agree, further investigation is needed, a serious problem that requires a real solution exists. Since the current increased with the pump running, that branch circuit & pump is the first suspect.

 

[hurk27]

Sounds like this could be a lost neutral for the service or a transformer, lost of the neutral between the main panel and the transformer can cause the house to draw current through the grounding system, and even the transformer out at the pole, if the primary neutral is lost but the X0 is still connected to the secondary neutral, it can seek a return path through the house grounding.

These are the two areas I would look into.
This could be dangerous for the home owner.

 

[hurk27]

I agree, further investigation is needed, a serious problem that requires a real solution exists. Since the current increased with the pump running, that branch circuit & pump is the first suspect.

the load of the pump should not be placing a current on the grounding if the neutrals and grounding are kept separate? This is why this should be a service neutral problem?

 

[BAHTAH]

Sump Pump

Sump Pump

When I pushed the float switch on the sump the reading jumped to 6.8 amps.

I agree with SG-1. I would look at the sump pump circuit to be sure the ground and neutral are separated. If there is receptacle circuit near by you might try using an extension cord to run the pump and see if the problem goes away. IMO if it was a service neutral problem there would be other circuits in the home that would be affected. Also if you talked with the owner about this problem you may want to drop him a note stating that this is a hazard and should be repaired just to cover you rear end if someone gets hurt and some lawyer goes after anyone who knew there was a problem. I have always made it a habit on billings to do that, if I see some problem that I know exists but was not asked to repair. No one will care that you did not get a job, only that you were aware of the hazard and did not inform the owner.

 

[tonyou812]

I agree with SG-1. I would look at the sump pump circuit to be sure the ground and neutral are separated. If there is receptacle circuit near by you might try using an extension cord to run the pump and see if the problem goes away. IMO if it was a service neutral problem there would be other circuits in the home that would be affected. Also if you talked with the owner about this problem you may want to drop him a note stating that this is a hazard and should be repaired just to cover you rear end if someone gets hurt and some lawyer goes after anyone who knew there was a problem. I have always made it a habit on billings to do that, if I see some problem that I know exists but was not asked to repair. No one will care that you did not get a job, only that you were aware of the hazard and did not inform the owner.

There acually was a problem with other circuts in the house. I was there to give a quote on a basement reno and he just happened to mention it. I personally am tired of giving advice only to have another bloke do the work for less because I already told the HO whats wrong.

 

[LarryFine]

I put my amp meter on it and it only read 1.8 amps (granted there were no real loads on the house save for a few lights).When I pushed the float switch on the sump the reading jumped to 6.8 amps.

I think there's a problem with the service's neutral conductor somewhere. Have you tried the compare-the-line-to-neutral-voltages test? Have the meter reading when you trip the pump, too.

 

[tonyou812]

I think there's a problem with the service's neutral conductor somewhere. Have you tried the compare-the-line-to-neutral-voltages test? Have the meter reading when you trip the pump, too.

Yea I thought of doing that but then I thought to myself" why am I about to fix this for free"...? I wasnt awarded the origional job yet. The HO was basicaly looking over my shoulder the whole time. I told him that this is not good and the other "EC" basically put a band aid. Not to mention that he trimed the #6 he ran to fit the bus bar.
Im not to worried though the guy doesnt plan on acually living there for a few months.If I get the work I will let you all know what the problem was.

 

[LarryFine]

Yea I thought of doing that but then I thought to myself" why am I about to fix this for free"...? I wasnt awarded the origional job yet.

I suggest a proposal (at a price) to diagnose and recommend a fix, which will specify the repair costs. That way, if you don't do the repair, at least you get paid for doing the troubleshoot.

 

[tonyou812]

I suggest a proposal (at a price) to diagnose and recommend a fix, which will specify the repair costs. That way, if you don't do the repair, at least you get paid for doing the troubleshoot.

Yea your right...I should have done that. I didnt even think of it. But it was already 6:30PM and I was already there longer than I wanted to be.
The other electrician also told him that he had a ground loop but I dont see how this situation qualifies as a ground loop, but I didnt want to open that one up, im not sure the HO would have followed the theory. Am I correct that this isnt the same as a ground loop..?

 

[SG-1]

Am I correct that this isnt the same as a ground loop..?

I do not see how this could be called a ground loop. Since the NEC does not define ground loop, it can mean different things to different people. I do not consider a re-grounded neutral a ground loop. I agree with Larry Fine's diagnosis since you stated other circuits are having problems too.

I would consider this home hazardous for occupancy until this matter is resolved.

 

[quogueelectric]

Many improperly trained electricians are tought that to make something safe that is energized just ground it. You first hae to identify where the objectional current current is coming from. This can easily be accomplished by flipping a few breakers with walkie talkies. Try to think more from the elimination of objectional current rather than overcoming a possible electrocution by grounding the equipment.