Help solve my inverter mystery

[RPAspey]

the neutral is also called a grounded conductor. so called because its bonded ( connected ) to ground at the panel, but it carries return current from the device ( your appliances, tv, heater, etc) back to the electric panel at neutral volts. ground and neutral aren't the same.

At your inverter neutral would be the longer slot that the plug goes into. On the connection at the receptacle it would be the silver screw. ground is the green screw.

If for some reason the two silver and green screw connections were reversed when the isolated plug was made, that might be related to your mishap.

the warning is because the shell of the inverter may have a different potential than the metal in your camper. and as I mentioned earlier, a different potential than the neutral. Often the neutral is thought to be the same as ground. it ain't. neutrals might have no (0) potential but they DO carry current. anyway, if the shell of the inverter isn't grounded, and there is a fault in anything plugged into the inverter plug (remember that the ground in the plug is connected to the inverter shell) that goes to any metal part in the device you could get shocked. or there could be high voltage on the case of the inverter because of the fault.

Man I wish you lived near central PA. I'd come over to help you out.

[Top B]

Originally Posted by Realrotor

Maybe a dumb question. What is neutral? Would that be the ground terminal?

A neutral is a wire that is not electrically charged (neutral). In a typical wiring configuration, the neutral wire is the white wire and is also called the grounded conductor. Electricity runs from the black wire, or hot wire, and the unused portion returns through the neutral wire.

[Realrotor]

Originally Posted by RPAspey

the neutral is also called a grounded conductor. so called because its bonded ( connected ) to ground at the panel, but it carries return current from the device ( your appliances, tv, heater, etc) back to the electric panel at neutral volts. ground and neutral aren't the same.

At your inverter neutral would be the longer slot that the plug goes into. On the connection at the receptacle it would be the silver screw. ground is the green screw.

If for some reason the two silver and green screw connections were reversed when the isolated plug was made, that might be related to your mishap.

the warning is because the shell of the inverter may have a different potential than the metal in your camper. and as I mentioned earlier, a different potential than the neutral. Often the neutral is thought to be the same as ground. it ain't. neutrals might have no (0) potential but they DO carry current. anyway, if the shell of the inverter isn't grounded, and there is a fault in anything plugged into the inverter plug (remember that the ground in the plug is connected to the inverter shell) that goes to any metal part in the device you could get shocked. or there could be high voltage on the case of the inverter because of the fault.

Man I wish you lived near central PA. I'd come over to help you out.

Hey, I'm only a couple of thousand miles away in Quartzsite. Come on over.

So I'm gonna pull the connections apart on the inverter output cable. What, exactly, should I look for?

[RPAspey]

before you start tearing anything apart, use a meter to ring thru your cable. what you would do is using the ohm setting on your meter, make sure that the wide blade of the plug is wired to the wide slot in the outlet. do so for the ground (roundish hole/ roundish pin) at both ends, and the shorter slot/blade. what you want to verify is that nothing is crossed. The meter should display a very low number like 2 or 3 ohms, on a match. also measure resistance from the wide blade (neutral) to the roundish ground pin this should be open I'm not sure what you meter will show as an open, it should be the same as when the leads aren't touching anything. If you have a mismatch that will need fixed. Any reading on the wide blade to ground pin and you found your problem!

let me know what you find.

[prairiecamper]

one day I was hooking up the cables from the battery to the inverter and accidently hooked up with wrong polarity for a fraction of a second it smoked the inverter, never could get that smoke back in!!

[Realrotor]

Originally Posted by RPAspey

before you start tearing anything apart, use a meter to ring thru your cable. what you would do is using the ohm setting on your meter, make sure that the wide blade of the plug is wired to the wide slot in the outlet. do so for the ground (roundish hole/ roundish pin) at both ends, and the shorter slot/blade. what you want to verify is that nothing is crossed. The meter should display a very low number like 2 or 3 ohms, on a match. also measure resistance from the wide blade (neutral) to the roundish ground pin this should be open I'm not sure what you meter will show as an open, it should be the same as when the leads aren't touching anything. If you have a mismatch that will need fixed. Any reading on the wide blade to ground pin and you found your problem!

let me know what you find.

I checked resistance at each end between the ground pin and the neutral pin. Shows infinite resistance.

As for checking continuity between the plug and the outlet, I've been trying to figure out a way to connect the leads of my meter to opposite ends of the cable without stringing 20 feet of wire through the camper window. Seems easier to take the connections apart and just look at the wiring to see where it connects.
As a substitute I plugged an AC circuit analyzer into the outlet. It reads OK.
Should I rely on that?
Thanks for the help.

[RPAspey]

I'm not sure how a outlet checker would work with an inverter. Personally I wouldn't trust what it says. If you are confident that you can visually confirm the connections, that should be ok.

Make sure you measure both neutral and ground to the chassis frame too.

[RJHuser]

Originally Posted by jonnys_walkers

This article shows you hook your cables directly to the battery, not grounding through the frame.
I am not sure if this caused your first one to fry or not. I just followed what the video said.

Not to highjack this thread, but I just watched the above video on the 1000 Watt Pro-Series Pure Sine Wave Inverter, and noted a MAJOR error in the connection sequence.

The video says and shows the positive cable being connected to the positive terminal of the battery first. THIS IS EXTREMELY DANGEROUS. In doing this, if the other end of the positive cable were to contact the frame of the vehicle, a catastrophic accident could incur, including the explosion of the battery and/or a fire.

The correct connection method is to connect the positive cable (and, while your at it, the negative cable) to the inverter first, then, and only then, connect the positive cable to the positive terminal of the battery. The very last connection should be the connection of the negative cable to the negative terminal of the battery. An additional precaution would be to recommend protecting both battery terminal ends with electrical tape until immediately prior to making up the connection.

Also, I just noticed the installation manual has this incorrect connection sequence in it.

I sent an e-mail to the vendor about this. If I hear back from them I'll post it here.

[Realrotor]

Originally Posted by RJHuser

Not to highjack this thread, but I just watched the above video on the 1000 Watt Pro-Series Pure Sine Wave Inverter, and noted a MAJOR error in the connection sequence.

The video says and shows the positive cable being connected to the positive terminal of the battery first. THIS IS EXTREMELY DANGEROUS. In doing this, if the other end of the positive cable were to contact the frame of the vehicle, a catastrophic accident could incur, including the explosion of the battery and/or a fire.

The correct connection method is to connect the positive cable (and, while your at it, the negative cable) to the inverter first, then, and only then, connect the positive cable to the positive terminal of the battery. The very last connection should be the connection of the negative cable to the negative terminal of the battery. An additional precaution would be to recommend protecting both battery terminal ends with electrical tape until immediately prior to making up the connection.

Also, I just noticed the installation manual has this incorrect connection sequence in it.

I sent an e-mail to the vendor about this. If I hear back from them I'll post it here.

If they are that careless about their documentation I can see how they could have failed to consider what could happen when the inverter is grounded to an RV with an AC circuit. I'm convinced now that the inverter should NOT be grounded to the frame despite what the company says. I'll be sending them an inquiry.
Thanks to all for the suggestions.
(BTW, I checked the wiring from the inverter to the outlet. Nothing wrong.)