Forum Discussion

deleted-2's avatar
deleted-2
Explorer
Oct 10, 2013

300 watt inverter input wiring

Morning all!

I did search a bit thru a few inverter threads here.
Hard for me to tell what's going on though.

Bought a Samlex pure sign inverter to run a tv and disc player in the fiver.
I know I need to get close to the batteries.
Samlex recommends 4ga input wire for runs over 10 feet and longer!
At least that's what I thought I read...

Could I steal DC from the 12 volt fuse box I was hoping the input there might be 6ga or higher?

DC runs to the Genesis and the antenna amplifier in the rear on 10ga wiring, yet the voltage drop is too severe for the inverter.

Still don't know how I can get 120 to the back wall.
This coach has 3 slides so getting wire back there will be a challenge.
Maybe one of the breakers isolates the rear wall outlets.
Could go up to and down the ceiling to the rear wall maybe with wiremould.

Just a note:
We have three size 29 batteries and a 2 circuit marine cut-off switch installed also.

I appreciate your help as always.
jim
  • I would use the 4 awg from battery to inverter. Put an ANL fuse in the line. Use marine grade battery cable for the 4 awg. The transfer switch is a good idea.
  • Looks like I'll have to go back to Amazon or maybe Don Rowe for a transfer switch too...

    It's always sumpthin.
    Thanx again for the help everyone.
  • If you are going to run it off the fuse panel I would check the wire from the battery to the panel. Mine had about 20' of #8 wire. That plus the wire you add may result in too much voltage drop. I replaced the battery to panel/converter with #4 wire when I replaced the old converter with a modern 4 stage converter.
  • I have a 300 PSW samlex and have a connector on a dedicated fuse on the DC panel.

    The problem is if and when I use my heater. The heater drops the voltage too much with the TV on the inverter. This is with two 6 volt golf cart batts. I get much better results running it directly off the batteries at the batteries.
  • I used a 30a DPDT RV transfer switch for the branch circuits.
    Put two relays in one box to save space.

    If doing it today I would use the smaller Prowatt relay.
  • DPDT for incoming shore power? What amperage relay did you select? Or is yours a mechanical throw switch?
  • #6 from the panel is fine. #8 is fine. You only need #4 to get full surge performance that you will never ever need. Probably you will never max out the inverter and more commonly use 75w to 250w and no surge.

    Since you are right there at the distribution panel connect a small transfer switch in the one circuit you need. I recommend Xantrex Prowatt for about $50.

    This is how mine is wired... except I went two transfer switches and ALL outlets share the 300w.

    No wire to pull, just make the connections. Done.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,198 PostsLatest Activity: Feb 12, 2025