Electrical Phantoms

[Cruiseomatic]

'06 Cavalier. 30 Amp service soon to be 50. Progressive Dynamics PD4560 dist. box.

Now for the weird and the question, Lol.
Everytime the converter is on my radios pickup tons of RFI and the television signal is lost(DTV). Pulled out the volt meter and did some reading: I have 34 VAC from chassis ground to 120 VAC ground. If I pull all DC grounds(Converter and chassis)and shut the converter down, I still have lights although very dim. Also, if the chassis ground rubs with the 120VAC ground wires on branch circuits, the converter sounds like it is arcing even though, the 120VAC ground is not connected. I did find one ground loop. Had a small gauge wire that was grounded somewhere but when disconnected, Has no effect on anything else. Tried to get a schematic from gulfstream and they're no help. If I probe the 120VAC neutral to ground with the ground pulled, I still have 34 VAC. Connected, 1.2VAC. If I kill every breaker there is no voltage. With every breaker I switch back on, The voltage goes up. I even have AC voltage at the converter output on or off. And by off, I shut the breaker off and checked with voltmeter. 0 Volts. Checked to see if any DC circuits were back feeding voltage, None are. What am I looking at here and what do I need to correct it? I'm fairly proficient with electricity. Thats also why I was "playing" in a live box. And even on my surge protectors that show if it is grounded, With the 120 VAC ground pulled, it still shows a weak ground. I did ground the aluminum body a while back and looks like I should have... Looked all down the chassis and see nowhere 120VAC should come into contact with it.
Also found out 30 VAC doesn't even tingle. Or I'm that used to it. If something doesnt make sense, Please let me know. This is REALLY confusing.
Thanks in advance.
Update: Did a continuity check across neutral and ground, Shows dead short. This is going through just the wire coming into the box, Not connected to any circuits. Although, My plug tester shows everything is fine.

[Cruiseomatic]

Yes, Ground is ground. However, AC safety grounds should NOT act as a return for DC in my experience. Not to mention, I should not have AC voltage in the DC system.

[enblethen]

Basically, ground is ground. There is some ypes of installation that uses speically filtered grounds but general all grounds should be connected to one.
This is why ground rods are necessary on AC systems. The utility in most North American electrical systems tie the transformer cases to ground at the pole or transformer location. When the neutral in the feed to the service fails, the ground would carry the unbalanced load back to the transformer.
When the soil doesn't have enough minerals or moisture this doesn't happen.

[Cruiseomatic]

Hiring one is too expensive and the only one I could "befriend" is the one who did the ground modification. He called it "Cheating the neutral." As far as the ground rod, Thats what I thought. As far as I know, When the house was built in the early '70's, (1970 I think.) They used a water pipe as the ground. I don't see any ground rod(s) by the service panal or meter. I'll work on getting him to check it out this weekend or next. But lets move on to the other issues. AC and DC "flirting". How can DC use the AC for return ground and DC grounds conduct 120VAC with no shorts in either system.

[jamnw]

Cruiseomatic wrote:
Jamnw, Not in the trailer but in the house that is also fed by the same panel, A receptical was "modified" to use the ground as a neutral. As far as I know, None of the outlets in the trailer were overloaded.

I have to say you need to hire or befriend a competent electrician to come put eyes on your situation and help you.

The first problem is the source. It needs to be 100% to troubleshoot a problem like yours.

Using the "ground" on a circuit is dangerous. The neutral is NOT ground although it is connected to ground. It is the easiest path back to the power source. ie transformer feeding your home

Your ground is/should be going to a ground rod at your home. This ground may or may not be at the same potential as the power company neutral.

I had a telco customer who had rearranged their home. Every time lightning struck in the vicinity ALL their phones would blow.
Phone interface is supposed to be grounded to the power ground. They had moved the power ground to the other side of the home. They left the telco grounded to the old ground rod.
That difference in ground potential was causing their problem.
They were mad as hell at Bellsouth thinking it was our fault. When I proved to them the problem was caused by them, they were very humble. I had to bury a #6 unshielded wire between the two ground rods.
Solved their problem.

You have to get your source right.

[Cruiseomatic]

Jamnw, Not in the trailer but in the house that is also fed by the same panel, A receptical was "modified" to use the ground as a neutral. As far as I know, None of the outlets in the trailer were overloaded.

[sljkansas]

Let me ask this, if one outlet has reversed wiring, hot (Black wire) on neutral, neutral (white wire) on hot, or the ground crossed with neutral, wouldn't this cause a hot ground and affect the whole circuit.

I have had run into this a few years ago, in offices that had added additions and the old wiring was not wired the same as the new.

Also have seen where an outlet had been overloaded and/or overheated to where carbon from arcing had caused problem (kind of like a loose connection will corrode and cause a problem.

This may have been addressed and I missed it. Just my 2 cents worth

[jamnw]

Cruiseomatic wrote:
Checked the cable, Its good. Something tells me that when the ground was used as a neutral in anouther receptical that is fed from the main panel, It is screwing with everything else.

Was a ground used as a neutral on one of the AC circuits in the trailer?

[enblethen]

Reconnect all wiring together. Then test for continuity from the male 30 amp cord body to the 120 volt distribution panel.
I am still thinking you have a bad service connection where you are plugging in.

[Cruiseomatic]

Checked the cable, Its good. Something tells me that when the ground was used as a neutral in anouther receptical that is fed from the main panel, It is screwing with everything else.

[jamnw]

enblethen wrote:
Un-plug the cable. Test cable with Ohm meter. Should be no resistance between conductors.
You should have resistance looking back at the service between the neutral and ground.

You will not have resistance between the ground wire and the neutral wire when looking from the outlet, back to the main breaker box.
Neutral and ground are at the same potential.

CHousehold electric circuit

Neutral is the return to ground for the circuit.

My understanding of the "ground" wire is to protect the end user in case the equipment they are using becomes energized. The current will flow back to ground through the ground wire instead of through YOU.
If that ground is broken somewhere. YOU become the source to ground.


OP
Now that you have determined that your supply cable conductors are not shorted. I would make sure they are all intact. By that I mean to check continuity on each conductor from end to end. That would ensure they are all good from end to end.

*now you could have a partially open neutral, and that test would not indicate that. It would be pretty difficult to find that. The resistance might be slightly higher in a partially open wire, and you're most likely not going to see that.

**we see partial opens all the time in the telecom industry in the outside cables. They're hard to find. Causes that "crackling/frying" sound on the phone.

If you have an open neutral in your supply cable, you could be using your ground wire as a return path. You don't want that.

[enblethen]

Un-plug the cable. Test cable with Ohm meter. Should be no resistance between conductors.
You should have resistance looking back at the service between the neutral and ground.

[Cruiseomatic]

Right, That was with the shore cord still plugged in. Then I checked the service connection and it was still present.

[enblethen]

" The short was still there on the shore cable but not in the main wiring"
This is the short you need to get rid of. Which conductors are shorted.

[Cruiseomatic]

No continuity at all. Shows open.