I'm adding a 600 watt inverter and the plan is to put it in the pass thru storage compartment, which will be just behind the batteries on the trailer tongue. My first inclination was to run the cables under the front of the trailer and cut a hole in the floor but to do that I'll have to also cut into the plastic stuff (not Coroplast, kind of like a plastic tarp) completely covering the trailer's underbelly. The more I think about it, the more I worry about being able to completely seal up even a little hole once the cables are passed thru. I think I've seen where someone drilled thru the diamond plate on the front and avoided the underbelly altogether. If so, what kind of junction box, bushing or whatever should I use to run the cables through? Any advice would be much appreciated by this lady "senior citizen" before I go cutting holes in my TT.

3940wez12 wrote:I'm adding a 600 watt inverter and the plan is to put it in the pass thru storage compartment, which will be just behind the batteries on the trailer tongue. My first inclination was to run the cables under the front of the trailer and cut a hole in the floor but to do that I'll have to also cut into the plastic stuff (not Coroplast, kind of like a plastic tarp) completely covering the trailer's underbelly. The more I think about it, the more I worry about being able to completely seal up even a little hole once the cables are passed thru. I think I've seen where someone drilled thru the diamond plate on the front and avoided the underbelly altogether. If so, what kind of junction box, bushing or whatever should I use to run the cables through? Any advice would be much appreciated by this lady "senior citizen" before I go cutting holes in my TT.The hole you put through the floor won't be the first on your trailer.Holes for plumbing and electrics have already been put in the floor of your trailer by the manufacturer. Do what you gotta do and then blast the hole with some good caulk.

What size is the existing feed to your 12 volt panel? Maybe you can use that? I had a 400 watt unit in my previous rig that I just fed of the neutral and positive feed at the panel, and that put the inverter where I wanted it.You might be able to upgrade the feed wires to the battery if need be. For our purposes, the biggest load was the coffee grinder at 160 watts.

#1nobby, I'm not so worried about the floor itself, it's that plastic stuff that covers the whole underside. So far, there are no holes in it anywhere...and I've crawled under and looked. Wires and plumbing are apparently between the floor and the underbelly covering. Another question...is there any reason the inverter should not be mounted to the front wall of the pass through rather than the back wall. The front wall would be closer to the batteries. Thanks for your help.

You have a good plan by mounting the inverter as close to the batteries as you can. My inverter is mounted on the front wall of the pass-through area to be close to the batteries. My wiring runs out of the bottom of the trailer which also has an enclosed underside as you described. There is sealant around the the wires where they exit the underside cover.I also have two transfer switches so the electrical outlets in the trailer are automatically powered when the inverter is turned on. This has been a nice modification.

If drilling through the wall, a grommet is the thing you need to prevent the cables from chafing. You can fashion one, yourself, using plastic tubing or pipe. Otherwise they are sold all over.

Advice for inverter installation | Good Sam Community

_1nobby
Explorer
Jun 09, 2016
3940wez12 wrote:
I'm adding a 600 watt inverter and the plan is to put it in the pass thru storage compartment, which will be just behind the batteries on the trailer tongue. My first inclination was to run the cables under the front of the trailer and cut a hole in the floor but to do that I'll have to also cut into the plastic stuff (not Coroplast, kind of like a plastic tarp) completely covering the trailer's underbelly. The more I think about it, the more I worry about being able to completely seal up even a little hole once the cables are passed thru. I think I've seen where someone drilled thru the diamond plate on the front and avoided the underbelly altogether. If so, what kind of junction box, bushing or whatever should I use to run the cables through?
Any advice would be much appreciated by this lady "senior citizen" before I go cutting holes in my TT.

The hole you put through the floor won't be the first on your trailer.

Holes for plumbing and electrics have already been put in the floor of your trailer by the manufacturer. Do what you gotta do and then blast the hole with some good caulk.
Artum_Snowbird
Explorer
Jun 09, 2016
What size is the existing feed to your 12 volt panel? Maybe you can use that? I had a 400 watt unit in my previous rig that I just fed of the neutral and positive feed at the panel, and that put the inverter where I wanted it.

You might be able to upgrade the feed wires to the battery if need be. For our purposes, the biggest load was the coffee grinder at 160 watts.
3940wez12
Explorer
Jun 09, 2016
#1nobby, I'm not so worried about the floor itself, it's that plastic stuff that covers the whole underside. So far, there are no holes in it anywhere...and I've crawled under and looked. Wires and plumbing are apparently between the floor and the underbelly covering.

Another question...is there any reason the inverter should not be mounted to the front wall of the pass through rather than the back wall. The front wall would be closer to the batteries. Thanks for your help.
MikeInOregon
Explorer
Jun 09, 2016
You have a good plan by mounting the inverter as close to the batteries as you can. My inverter is mounted on the front wall of the pass-through area to be close to the batteries. My wiring runs out of the bottom of the trailer which also has an enclosed underside as you described. There is sealant around the the wires where they exit the underside cover.

I also have two transfer switches so the electrical outlets in the trailer are automatically powered when the inverter is turned on. This has been a nice modification.
westend
Explorer
Jun 09, 2016
If drilling through the wall, a grommet is the thing you need to prevent the cables from chafing. You can fashion one, yourself, using plastic tubing or pipe. Otherwise they are sold all over.
bigrigfixer
Explorer
Jun 12, 2016
What kind of caulk to seal up the plastic under the trailer where the cables go through?
westend
Explorer
Jun 12, 2016
bigrigfixer wrote:
What kind of caulk to seal up the plastic under the trailer where the cables go through?
If it's that typical woven plastic tarp-like material, I'd use Gorilla Tape or something similar. If it's hard plastic sign material (Coroplast), I'd use urethane landscape foam in a spray can. That stuff sticks to anything.
Big_Love
Explorer
Jun 12, 2016
Mounting the inverter as close as practical to the batteries is key. I also mounted my 2000w inverter on the front wall of the pass through, and carefully drilled holes for the thick cables into the floor. Using recommended cable size and the shortest distance to batteries will help your inverter function efficiently.
nike_holley
Explorer
Jun 12, 2016
If I were doing it... I'd use a 'strain relief' for the wall penetration... they tighten to the wall with a nut, & have a rubber seal where the cord/wire goes through that is tightened down after the wire is passed through...

Nate
SoundGuy
Explorer
Jun 13, 2016
3940wez12 wrote:
Another question...is there any reason the inverter should not be mounted to the front wall of the pass through rather than the back wall. The front wall would be closer to the batteries.

Personally I wouldn't (and didn't) mount my inverter to the front wall because it would be taking up space better used in other ways. I instead built an open frame shelf (for ventilation) and suspended it from the storage compartment "rafters" - inverter is out of the way, retaining maximum space for storing other more important items. :)