Wheelhouse grounding questions

[Cooperman]

1. Can I use the trailer chassis for my DC branch circuit returns, rather then run a wire back to the power center? since I'm grounding my WFCO power center to the trailer chassis, and how does that affect the trailer lighting when the trailer is attached to the tow vehicle?

2. The AC side of the power center is only grounded through the plug to the generator?

[papadarv]

Not sure why but my Motorhome and close friend travel trailer both have a DC ground buss inside the Converter/Power Center. All Coach DC grounds are routed to the buss. My vehicle lights as well as the trailer travel use the frame for DC Ground. I am thinking because there are 2 power sources, one from the engine alternator and one from the coach generator, there might be an issue with both being grounded together.

[Moon Lake Refuge]

I did both in a lot of cases.  Main issue I kept hearing was potential corrosion at the frame where it was grounded causing a faulty connection.  For how cheap wire is just buy a 500 foot 16/2 jacketed spool online for 40-50 bucks to be safe

[Lip_Ripper Guy]

AC & DC should both be grounded to the frame.  I've never grounded AC to the frame, but I probably should.

Using the frame as a return on the DC side is a terrible idea, IMO.  It takes very little for that connection to come loose.      

[YettiStyle]

Don't ground anything directly to your fame, you are just asking for problems.  Running two wires is just as easy as running one and you are saving yourself a lot of potential headaches for an extra $20.  I used a Progressive Dynamics power center but I think its fairly similar to the WFCO.  Get yourself a ground bar and an extra large ground lug at Menards to handle all your grounds, found by the breakers and electrical panels (Ground Bar, Ground Lug).  Using a thick gauge wire, connect the "-" side of the battery to one of the large ground lugs and connect the DC side of your WFCO to the other large ground lug.  Now just run all your other grounds to the ground bar and you are good to go. 

 

Grounding to the frame isn't going to do anything, you still aren't going to get an earth ground.  Your actual house is earth grounded by driving a copper stake into the ground and everything is grounded through that.  You may think that since your frame is sitting directly in contact with ice that should provide a ground.  Fact is, water is actually a terrible conductor and won't provide a sufficient ground, the only reason electricity flows through it is because of the minerals inside.  All you need to do is have the DC tied back to the battery "-" and have the AC circuitry "grounded" to your service (generator or any other power source). 

[Hawg]

Run DC grounds EVERYWHERE, to the frame in multiple places, especially the tail lights. And back to the plug!!!! Look up wiring problem posts, It's always the ground!!!!!!!!!

Edited September 2, 2016 by Hawg

[Cooperman]

Thanks guys, I'm on it. Just picked up the grounding bar and installed it.

I think you're supposed to let the AC ground float in the wheelhouse, so if you hook up to your home power or a camping site, or generator your AC is grounded there? Something about double bonding that can cause problems?

Does anyone use an isolator, to keep the 2 charging systems separate?

[Hawg]

What is floating? Ground your DC everywhere, forget all those theories people tell you, ground, ground, and ground again. 

[Moon Lake Refuge]

Can't recall where but I read on an rv forum not to ground your ac and dc together.  Don't remember why but may be worth looking into. 

[YettiStyle]

On ‎9‎/‎2‎/‎2016 at 2:44 PM, Cooperman said:

Thanks guys, I'm on it. Just picked up the grounding bar and installed it.

I think you're supposed to let the AC ground float in the wheelhouse, so if you hook up to your home power or a camping site, or generator your AC is grounded there? Something about double bonding that can cause problems?

Does anyone use an isolator, to keep the 2 charging systems separate?

Correct with the AC ground floating.  The ONLY reason you should connect any of your DC circuits to the frame is if you intend on only running one wire and using the frame as a return.  I recommend using just using two wires and not worrying about any corrosion or bad connection issues. 

As far as the isolator goes, what two charging systems are you referring to?  Do NOT connect your AC and DC grounds to the grounding bar you installed, just the DC.  Your power center should already have 2 terminal bars inside of it.  One is for the AC neutral (white) and the other is for the AC ground (green/bare), do NOT connect any DC circuits to either of these terminal bars inside the power center.

Edited September 6, 2016 by YettiStyle

[Hawg]

"Using just two wires and not worrying about corrosion or bad connection issues"   =    Recipe for problems!                                                       

[YettiStyle]

2 hours ago, Hawg said:

"Using just two wires and not worrying about corrosion or bad connection issues"   =    Recipe for problems!                                                       

How do you figure?  You have the same odds of running a nail through two wires as you do one wire.  The only other opportunity for a problem would be a bad connection (solder, crimps, wire nuts).  When grounding to the frame you will need to use a ring terminal so you aren't cutting out any more connections.  BUT with a frame ground you have an increased probability of frame corrosion/electrolysis as well as a chance for bad contact between the ring terminal and frame. 

The only reason cars utilize frame grounding is for the weight savings which you won't experience with an ice shack.  Much of automotive electronics are high current so they require much thicker gauge wire than the 14-16 gauge you will be using in your ice shack. 

[carpshooterdeluxe]

On 9/7/2016 at 5:13 AM, Hawg said:

"Using just two wires and not worrying about corrosion or bad connection issues"   =    Recipe for problems!                                                       

I've wired 8 or 9 wheel houses in the last 16 years and none of my wiring connections have failed.  All were wired either pulling 2 conductor home runs to each device, or in the case of some lighting circuits, paralleled.  Even in the junction boxes where I used wire nuts, those have not backed off creating any loose connections.  Knowing what you are doing and using proper materials and methods goes a long ways.  You can use 1 wire and structure ground, or you can use 2 wires for your DC circuits, but if you don't use the proper connections & tools you'll have issues regardless.

[Hawg]

Carpshooter, I'll go along with that but not everybody does home runs. My biggest problems have always been tail lights and those aren't fun to chase. Seems like a pretty cheap insurance policy to me.

[LindellProStaf]

AND SOLDER everything.  Your wire is copper and the connectors are aluminum.  Recipe for failure.  Oxidation problem.  Solder the wire to the connectors so that oxidation/corrosion won't happen.  Crimping is not the answer.  Sucks to have to tear a wall apart due to a 25 cent connector not making connection anymore due to humidity and temp changes..   On fish houses, boats, boat trailers etc.  Solder everything..

[delcecchi]

Solder copper to aluminum?   Does that work?  Special flux?  Normally can't get solder to stick to aluminum.   And normal copper connectors don't work on aluminum wire either.  

[LindellProStaf]

Works just fine.  The aluminum connectors that are to be crimped solder to copper wire great.  I have done thousands of them.  I used to own a  business years ago and from day one we soldered all of them and crimped them....  And it just take a few seconds for each one.  Just use regular elec solder.  No flux needed.

I think the connectors are alum coated copper.  The regular old connectors that everyone uses..

[papadarv]

Auto frame ground started in 1915 when Henry Ford moved from the Carbide headlight to a Dynamo DC powered lights. The first lights were grounded by soldering the ground wire to the radiator cross bar. Todays average cars/trucks use around 1.5 miles of wire weighing about 75 #. Cost of raw copper is around $2.45 which does not include the making of the wire, connectors etc. If auto's used a return ground wire to the battery, the wire volume would double which would more than double the cost of wire on a single wire with frame ground as wiring labor would also double. Frame ground is used because ALL of the car electrical/electronic parts are attached to steel. It makes a lot of sense to use the frame as the ground. The primary reason for a auto frame ground is cost avoidance not weight.

It also makes sense  the Wheel House frame ground is used for trailer driving, break, signal, clearance lights because these lights are powered by the towing vehicle which uses a frame ground. When towing a trailer is frame to frame at the ball connection of the trailer in addition to the white ground wire in the trailer wire harness is attached to the trailer frame as well as the vehicle frame.

It doesn't make a whole lot of sense to connect the internal cabin powered stuff to a frame ground. When these things are built, a floor, usually wood, covers the entire frame. The walls are most likely closed cell spray foamed after the outside sheeting is installed which covers the vertical frame studs and ceiling members. Than run wire for lights, hole outlets, furnace, 12v power outlets,  etc.  Than an inside walls are covered with wood or panels, a rubber floor covering is added on top the wood floor. You than install the A/C - D/C converter, furnace, TV and other electronics. I don't believe anyone would take the time and expense to drill holes, grind the foam, destroying the fine finish work at each of the electronic devices to gain access to the frame just to have a frame ground. You will simply run two wires either A/C or D/C to the power source.

 

[Hawg]

Just to be clear, all my comments about redundant grounding were in regards to the 12 volt DC wiring, not the AC. AC is always two wire.