Inverter wiring issue I fixed

[Jdb]

On our "new to us" Vegas 24.1 the PO had an AIM 2000w Pure Sine Wave inverter installed. When my wife tried to use inverter power to run her hair dryer on low heat, the inverter kicked out.

So when we got back I looked into the issue. I found a very poor wiring job including these:
1) 4 guage cables coming off the inverter (should be at least 2 guage per AIMS install instructions)
2) the negative cable was connected to the 12 guage grounding wire coming out of the ATS !
3) the positive cable was run to the distribution panel, and "connected" to a 12V hold-down that was too small to hold the cable strands, so they simply inserted about 1/2 the strands and left the other 1/2 outside the hold-down.

I've corrected all this by running properly-sized cables to the coach battery negative and the positive coming off the 100amp fuse in the battery compartment. I may move the positive to ensure that the inverter is disconnected when the "On/Store" switch is shut off.

And...the inverter now passes the hairdryer test!

Dave

[16ACE27]

Originally Posted by Jdb

I've corrected all this by running properly-sized cables to the coach battery negative and the positive coming off the 100amp fuse in the battery compartment. I may move the positive to ensure that the inverter is disconnected when the "On/Store" switch is shut off.

And...the inverter now passes the hairdryer test!

Dave

That 100 amp breaker is only going to get you 1200 watts at best out of your inverter and the USE/STORE solenoid won't handle the inverter current either. Most inverter installs run through their own breaker directly to the battery bank.

[petefoss]

Correct, on my 31W the inverter is directly connected to the batteries and us independent if the rest if the 12V system. The only common connection is the 120V bypass built-in to the inverter.

[Jdb]

Thanks for the feedback!

I just ordered BlueSea Systems Fuse block and 200A fuse. I can upgrade this to 300A if I upgrade to a 3000W inverter

Dave

[Beau388]

Originally Posted by petefoss

Correct, on my 31W the inverter is directly connected to the batteries and us independent if the rest if the 12V system. The only common connection is the 120V bypass built-in to the inverter.

Best practice is connect the inverter's ground directly to the battery bank. The size of the cable (wire) is dependent on the max current draw and the distance of the run. My inverter is under the bed and the battery bank by the front door some 20 ft of cable run. The book answer for a 3% voltage drop is 1 AWG cable for 166 amps. Since Thor MC installed a 1000 watt inverter with 4 AWG cable, I added another 4 AWG wire and a 100 amp circuit breaker since it was what I had. For the return run, I had to buy 1 AWG cable ($55 from Lowes). No problem with my Xantrex Freedom Xi 2000 watt programmable inverter.

[Beau388]

Originally Posted by petefoss

Correct, on my 31W the inverter is directly connected to the batteries and us independent if the rest if the 12V system. The only common connection is the 120V bypass built-in to the inverter.

Best practice is connect the inverter's ground directly to the battery bank. The size of the cable (wire) is dependent on the max current draw and the distance of the run. My inverter is under the bed and the battery bank by the front door some 20 ft of cable run. The book answer for a 3% voltage drop is 1 AWG cable for 166 amps. Since Thor MC installed a 1000 watt inverter with 4 AWG cable, I added another 4 AWG wire and a 100 amp circuit breaker since it was what I had. For the return run, I had to buy 1 AWG cable ($59.80 from Amazon). No problem with my Xantrex Freedom Xi 2000 watt programmable inverter.

[petefoss]

My 2000 watt is under the fridge a few feet from the batteries under the stairs. One thing Thor sorta did right. I would have put under the jacknife on the other side of the stairs for accessibility. The techs that replaced my original 1800 watt inverter were both about ready to pull the fridge and go in from the top.

[MLP]

Originally Posted by Jdb

On our "new to us" Vegas 24.1 the PO had an AIM 2000w Pure Sine Wave inverter installed. When my wife tried to use inverter power to run her hair dryer on low heat, the inverter kicked out.

So when we got back I looked into the issue. I found a very poor wiring job including these:
1) 4 guage cables coming off the inverter (should be at least 2 guage per AIMS install instructions)
2) the negative cable was connected to the 12 guage grounding wire coming out of the ATS !
3) the positive cable was run to the distribution panel, and "connected" to a 12V hold-down that was too small to hold the cable strands, so they simply inserted about 1/2 the strands and left the other 1/2 outside the hold-down.

I've corrected all this by running properly-sized cables to the coach battery negative and the positive coming off the 100amp fuse in the battery compartment. I may move the positive to ensure that the inverter is disconnected when the "On/Store" switch is shut off.

And...the inverter now passes the hairdryer test!

Dave

This is why I like doing my own work, but I am a retired engineer and know better. Never trust most RV repair facilities unless they are all RVDA/RVIA certified techs. If the RV facility has RVDA/RVIA certified techs, they usually do the job properly.