LED Meters blowing??

[KeepItSimpleStupid]

There is nothing wrong with the 12 V reference (negative terminal) of your inverter to be connected to ground if this is indeed the connection that was removed. I'm relieved that there is only one such connection, for that's the way it should be.

The RV should be equipotential with the Earth. ie. It should NOT be able to be charged above the ground potential by lightning, etc.

In general, you wouldn't attach a ground rod to a trailer. The trailer is insulated from ground by the tires. The trailer NEEDS a ground reference when it's connected to AC.

Reminder, as I understand it, the 12V is supplied by the 120 V system.

One side of the 12V being grounded is a good thing.

 

[Reloadron]

Your RV should have two sources of power available if like most RVs. You have 120 VAC based on either 50 amp or 30 amp service. The AC is provided either by an on board generator or "shore power". If you look at the mains power in circuit breaker panel the mains breaker should be either 30 or 50 amp depending on the service the system uses. I am assuming your location to be US. The 50 amp service panels usually bring in 240 VAC split phase mains power just like a US residence. The cable used for the "hitching post" will be wired accordingly with the correct connector.

The RV also uses 12 VDC power for all the accessories that run on and require 12 VDC power. The 12 VDC power is provided by battery power and a 12 VDC converter. When running from 120 VAC the converter provides all 12 VDC power as well as charging the batteries.

If the RV has standard 120 VAC power outlets they should be wired identical to residential outlets. There is 120 volts hot or high, a neutral and a ground. Attached are some outlet images with resulting voltages. The first two images show measuring neutral to hot with the resulting voltage. The last image shows hot to ground. The voltages should be the same give or take. This shows that Ground and Neutral are tied together at the mains breaker panel. This can be done using a meter as shown or just go to any hardware or home improvement store and buy a simple 3 lamp outlet tester for about $10 USD.

The 12 volt negative power and the 120 volt neutral and ground should all be the same point. In the case of an RV this should be chassis ground.

Ron

 

[Searchlight]

Your RV should have two sources of power available if like most RVs. You have 120 VAC based on either 50 amp or 30 amp service. The AC is provided either by an on board generator or "shore power". If you look at the mains power in circuit breaker panel the mains breaker should be either 30 or 50 amp depending on the service the system uses. I am assuming your location to be US. The 50 amp service panels usually bring in 240 VAC split phase mains power just like a US residence. The cable used for the "hitching post" will be wired accordingly with the correct connector.

The RV also uses 12 VDC power for all the accessories that run on and require 12 VDC power. The 12 VDC power is provided by battery power and a 12 VDC converter. When running from 120 VAC the converter provides all 12 VDC power as well as charging the batteries.

If the RV has standard 120 VAC power outlets they should be wired identical to residential outlets. There is 120 volts hot or high, a neutral and a ground. Attached are some outlet images with resulting voltages. The first two images show measuring neutral to hot with the resulting voltage. The last image shows hot to ground. The voltages should be the same give or take. This shows that Ground and Neutral are tied together at the mains breaker panel. This can be done using a meter as shown or just go to any hardware or home improvement store and buy a simple 3 lamp outlet tester for about $10 USD.

The 12 volt negative power and the 120 volt neutral and ground should all be the same point. In the case of an RV this should be chassis ground.

Ron

Ron,

Thanks for the information. I will make those checks as soon as I get home today.

Your description for typical RV wiring is spot on. However, for my case here, this is more of a play/camp area for my disabled son. The RV will ALWAYS have 120VAC "shore" power (in the backyard) and will NEVER run off of a 12VDC battery. In my case, the 12VDC power converter allows us to run the 12VDC lighting inside the camper, though we also have 110VAC fixtures and outlets as well. I could probably just do away with the 12VDC power converter, but I felt like keeping it for the extra lighting.

Your last sentence though has me a bit confused. If the "12 volt negative power and the 120 volt neutral and ground should all be the same point" wouldn't this again cause my common ground issue with my meters? I guess I understand having the 120VAC ground connected to the 12VDC negative, but not neutral. Wouldn't this get me right back to where I started with the common ground issue?

Again, thanks for the help. It is important to know that it is greatly appreciated.

Corey

 

[Reloadron]

Hi Corey

Yes, when I said the grounds should all be common it would cause the problem. However, this is all by design of the power distribution system. This goes back to why they make meters that can share their power and measuring ground. The way things are tied is for safety reasons and compliance with NEC codes. Based on your previous post I pretty much assumed yours was not going to be thee typical RV and I hope all of this really works out well for your son.

While this link provides an overview of NEC Code section 551 there are other sections that apply. Also note on the first page of the link the RV owner is very smart having his wife make the shore power connection.

Let us know how the measurements go.

Ron