My wiring plans

[cracker39]

There has been LOTS of discussion on this matter, and LOTS of disagreement. I have my battery grounded to the chassis, and did have my 120 V grounded to the chassis as well, but removed that ground after some thought that it was a bad idea. My converter is grounded to the battery ground, thus to the chassis. Does this mean that my 120 V is grounded to the chassis as well? I just don't know. All I know is that everything works fine. None of my 12 V lights, fan, etc. rely on the chassis ground. All have ground wiring running back to the converter's ground wire. The running lights are grounded back through the wiring and connector to the tow vehicle's ground.

[bobhenry]

Dale's post got me to thinking I may have accidently done something very right.

With the negative leg returning 12 volts to the frame, would this have any effect to a/c gfi's grounded to the same frame ?

Everyone was so against mixing 12 volt and 120 I tried to keep them totally seperate and independent.

I even seperated my inside 12 volt courtesy lights and recepticals from my running light by providing seperate grounds ( negative return legs).

The ac circuits all return to a grounding bar and the ground bar is hard wired to the shore ground only.
My running light return hard wired all the way back to the tow vehicles ground.
The on board 12v courtesy circuits return to a different grounding bar and from there directly wired to the on board battery negative post.

DID I DO GOOD ? They all work properly and one catastrophic failure will be limited to only 1/3 of my circuits.

[cracker39]

I just took another look inside my main breaker box. I did start off with an AC 120V chassis ground, but removed it after reading some pretty scary stuff on this forum about possible shocks from the trailer (when standing outside) if there is a short inside.

The diagram on my WFCO posted by Sonetpro in march in this thread http://tnttt.com/viewto ... light=wfco shows a chassis ground for the 120V, but I eliminated mine with no apparent problems. My battery is grounded to the chassis and like Bobhenry, my running lights are on a completely separate ground circuit to the tow vehicle.

[wlooper89]

Sounds good to me. My setup is very similar. My four A/C outlets in the trailer are protected by a single 20 amp GFCI near the tail of the trailer. Now I am wondering if I should put a GFCI in the electrical compartment near where shore power enters on the trailer tongue. This would be instead of grounding the trailer chasis to 120V shore power ground. Anyone know of a reasonably priced 30 amp GFCI?

Bill

[cracker39]

With three GCFI outlets, two 15 amp circuit breakers in my converter box and the 30 amp breaker at the shore cable, I feel like I have enough GCFI protection without additional GCFI breakers.

[wlooper89]

Dale, that sounds great!
Another question has come to mind. The GFCI devices can be purchased with either automatic or manual reset. With manual reset the reset button has to be pushed each time the power is interrupted, as when shore power is unplugged and then replugged into the trailer. With automatic reset power is restored automatically after an interruption. If there is a ground fault the circuit will stay open until reset with either type, except if power is interrupted and comes back on the automatic one will reset itself. The person at North Shore Safety said he would recommend the automatic type for an RV. The example he gave for the manual type was with a power saw. If someone was cleaning around the saw during a power outage, not realizing it was turned on, it could start up immeciately when the power is restored. I am still thinking about which might be better.

Bill

[cracker39]

As I said, I only have the individual dual wall sockets that are GCFI (under $10 each at Home Depot but I got mine at Hargor Freight for about $6 I think). There is a red reset button, But, mine don't need resetting each time I plug in the converter. They have never gone off that I know of.

[wlooper89]

Surprisingly my GFCI that protects four A/C outlets tripped last time we camped. There was a big electrical storm and heavy rain when this happened and I wonder if that could be the reason. Perhaps an extension cord got wet. I reset the GFCI and things worked normally after that.

My electrical compartment is a metal box attached to the trailer tongue and is not grounded to shore power ground. And my present GFCI for the outlets is downstream of the electrical compartment and protects neither it nor the trailer frame. After reading some of the earlier discussion in this topic, I have become concerned that we could be shocked if we touch the metal box or trailer frame while standing on wet ground, if there is a short circuit.

To reduce this concern I have ordered a new GFCI from North Shore Safety. It will connect directly to the shore power inlet in the electrical compartment and protect the whole trailer. I got the automatic reset 120V 30A splice-in type. The model number of this one is PGFS-13105. The following link has a picture and description. http://www.nssltd.com/pdf/30%20Amp%20Perm.pdf

I believe that for my electrical setup the extra peace of mind will be worth the cost of this item.

Bill

[wlooper89]

The ac circuits all return to a grounding bar and the ground bar is hard wired to the shore ground only.
My running light return hard wired all the way back to the tow vehicles ground.
The on board 12v courtesy circuits return to a different grounding bar and from there directly wired to the on board battery negative post.

My D/C setup is the same as bobhenry's. I believe this means the trailer chasis has a D/C ground only when the tow vehicle is connected. The chasis of the tow vehicle would be connected to the trailer chasis, either by the wire connection or through the hitch itself. And normally then A/C shore power would be unplugged, unless the tow vehicle is left connected overnight.

Perhaps I should make my A/C setup like bobhenry's as well and connect A/C ground to the trailer chasis and shore power ground. I have GFCI protection but I wonder if the GFCI would even trip if there is a short to the trailer chasis with the chasis not grounded to shore power. Maybe not until a person touches the chasis while standing on wet ground? Probably then the GFCI would trip after sensing the current running through the person to ground. I wonder how much of a shock that would be. Still confused.

Bill

[bobhenry]

The ac circuits all return to a grounding bar and the ground bar is hard wired to the shore ground only.
My running light return hard wired all the way back to the tow vehicles ground.
The on board 12v courtesy circuits return to a different grounding bar and from there directly wired to the on board battery negative post.

My D/C setup is the same as bobhenry's. I believe this means the trailer chasis has a D/C ground only when the tow vehicle is connected. The chasis of the tow vehicle would be connected to the trailer chasis, either by the wire connection or through the hitch itself. And normally then A/C shore power would be unplugged, unless the tow vehicle is left connected overnight.

Perhaps I should make my A/C setup like bobhenry's as well and connect A/C ground to the trailer chasis and shore power ground. I have GFCI protection but I wonder if the GFCI would even trip if there is a short to the trailer chasis with the chasis is not grounded to shore power. Maybe not until a person touches the chasis while standing on wet ground? Probably then the GFCI would trip after sensing the current running through the person to ground. I wonder how much of a shock that would be. Still confused.

Bill

Bill my ac circuits are not grounded to the chassis they ground directly back to the shore power source ONLY. I have accidently shorter out wires while wiring a couple circuits hot and the GFCI that is the 1st load after entering my trailer tripped as well as the source gfi

[wlooper89]

Bill my ac circuits are not grounded to the chassis they ground directly back to the shore power source ONLY. I have accidently shorter out wires while wiring a couple circuits hot and the GFCI that is the 1st load after entering my trailer tripped as well as the source gfi

Sorry I misinterpreted your previous note. Now I understand, and your GFCI's did their job perfectly. Earlier I spoke again with the salesperson at North Shore Safety with whom I had placed my new GFCI order. He then talked with their engineer. They said that one side of A/C could short to the ungrounded trailer chassis and nothing would happen, but if something or someone completes a path to ground then the GFCI would trip if the short is downstream (load side) of the GFCI. My example was a person standing on wet ground touching the chassis. He said the trip happens in milliseconds and should prevent harm to the person. This confirmed for me the electrical setup I wanted after hearing what you and others have done.

The photo below shows my electrical compartment attached to the trailer frame. My new GFCI connects directly to the shore power inlet and is mounted on the pasenger side of this box. I now realize that I could have a short circuit already, and not know about it, between A/C primary or common and this metal compartment. That will be easy to check now with a circuit tester. I may do that periodically since the GFCI at the shore power inlet will not trip unless something or someone completes the path to ground.



You and others in this topic have been very helpful to me. Many thanks!

Bill

[wlooper89]

Returning to the subject of A/C grounding, I painstakingly arrived at a decision not to ground A/C to the trailer chassis and ground A/C only to shore power ground. This was after reading a number of posts on this subject including recent posts by Bob and Dale.

While checking things out with an ohmmeter/circuit tester I found to my dismay that my metal shore power inlet itself grounded A/C internally to the inlet housing. The inlet attaches to my metal electrical compartment which in turn attaches to the trailer frame. So my A/C ground has been connected to the trailer chassis all along. Then I noticed the word "Grounding" stamped right on the front of the inlet.



Fortunately I was able to partially disassemble the inlet and remove the grounding strap.

Bill

[wlooper89]

My wiring plans appear below. Although I found some different component pictures, I owe a lot of the result to Joanne. I used electrical symbols for fuses and some of the switches and the other items are shown as pictures, some of them my own components.

One item that may be a bit unusual is the Battery Tender relay. I did not want the Battery Tender to try to charge the battery at the same time as the converter, so the relay prevents that if I should forget and position switches to use both chargers.

This is more of a flow chart than wiring diagram and the exact wiring is not shown. The first page follows the flow to A/C and D/C buses, and the second page shows some of the items that are in use now or might later be used on the buses. The audio/visual system is not yet in place and the PetCool is on hand but not installed.

I would be happy to try to answer any questions about my wiring, although I am far from being an electrical expert. In the past questions and comments have helped me make improvements.

Thanks, Bill

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[sportsta05]

Hi, I am new to the forum and hae a quick question. What type of wire is the best to use? I know stranded wire is prefered to a solid wire. I have seen RVI and GXL wires on some websites. Does anyone have a preference? Thanks for all the other info. I have really got a grasp on most of this wiring stuff.

Thanks again
Kyle

[wlooper89]

My A/C wire is flexible 10-3 from shore power to my converter. Then it splits into 2 cables that are flexible 12-3. Both are CSA type rated 300 volts and 105 deg. C. Lowe's had the flexible 12-3 wire and I ordered the flexible 10-3 from an arc welding suppy company. It is meant to be power cord for a welder. In some cases this cable was too bulky for where I needed to use it and I removed the outer jacket, just using the black, white and green insulated wires from inside. All of the #10 A/C wire is inside my electrical compartment on the trailer tongue, so I did not need a lot of it.

On the D/C side I used flexible #10 electric brake wire from an RV supply company. It has an outer jacket with insulated black and white wires inside. The rating type is not stamped on the cable, just 105 deg. C. I think the D/C wire is rated for a much lower voltage. Less than 100 V so I would not want to use that with A/C. I also ordered some #10 D/C wire from a solar power supply place, but the wires inside the cable were red and black instead of white and black. I decided to just use the white and black cable which is most common for an RV. #12 flexible D/C hookup wire connects my D/C lights and outlets from a junction box in the trailer.

I hope there is something in this post that helps and am sure a lot of others in this group are more knowledgeable about wiring than myself.

Bill