Tuesday, July 5, 2022


Ask Dave: What do I do about an E05 OL error code on Xantrex inverter?

Dear Dave,
When not on shore power or generator, I turn on the Xantrex 1800 XM PRO Inverter to run the residential refrigerator. When I turn the inverter on, I get an E05 OL error code. I have turned off the main breaker (again with no shore power or generator) and I still get the E05 OL code. What do I do next? Thanks. —Bill, 2015 Thor Miramar

Dear Bill,
We just worked on a 2015 Thor Challenger that had shot batteries and a Xantrex 1800 XM Pro Inverter that did not work along with a punch list of other items. I kept a copy of the Service Manual and according to it, the E05 OL code is an overload situation. Here is the description from the manual.

Unfortunately, the manual does not have a recommended fix for this situation, so I dug a little deeper and contacted the tech support at Xantrex.

The inverter operates on two modes: Shore Power Mode and Inverter Mode.

Shore Power Mode

When you are connected to shore power such as a campground source, or running the generator, the inverter goes into a standby phase and allows the power to pass through the unit. On the front you will see the knockouts for routing Romex or 120-volt wiring in and out of the unit. If the inverter is on, the green light will illuminate. However, you do not need the unit to be turned on as power should pass through even if it is off.

Inverter Mode

When the shoreline power drops below 90 Vac or is disconnected, the transfer switch automatically transfers power to the outlets from battery power and the yellow light is illuminated. The inverter does need to be on for this to work.

The 2015 Thor we worked on had no LED reading on the remote and we had no power. So we verified there was 12-volt power coming from the battery to the red (positive) and black (negative) posts on the inverter, and there was. This was after we had replaced the batteries with new lithium batteries and a Progressive Dynamics converter. And yes, we had sufficient power coming in.

Talking with the technician, he indicated the pass-through breaker could have tripped. He walked us through the reset procedure. Make sure the unit is not plugged into 120-volt ac power or the generator is not running. Then unhook the negative cable to the inverter for a few minutes and then it should reset. We let ours sit for 30 minutes, as he indicated all the capacitors need to drain power.

A surge protector would help

The tech indicated they would like manufacturers to install a subpanel with a 15A breaker or fuse on the AC power line coming into the inverter to help protect from power surges from the campground source or generators. This seems to be a big issue on the forums as most RV manufacturers simply hard wire the unit, as ours was. He did indicate using a surge protector like the Surge Guard model would help. Our owner did not have one of these, so that might be a good idea.

I’m not sure why a pass-through breaker tripping would affect the 12-volt or inverter side, but it seems to be common.

If you try this reset and it does not work, chances are you will need to send the unit in to have the pass-through breaker reset. Xantrex has a very good tech support department.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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Steve Hericks
27 days ago

I’m a mechanical engineer and a former RV plant engineer. The inverter manual does not mention placing a breaker on the INPUT to the inverter and it couldn’t protect it from anything anyway. A breaker is not a ‘power surge’ protective device. It is silly that the Xantrex Tech suggested it. Sounds like he was just looking for something to say.

One other thing the manual says that is likely relevant is NOT to bridge the input and output neutrals across the inverter. I would check to see if there is a grounded neutral anywhere between the grid inlet and the inverter, possibly at the grid/generator selector switch, if there is one. There should be no ground bonded neutrals anywhere in the RV but I have seen it many times. There may also be one in the breaker panel. That would create the undesirable neutral bypass. It would not affect the 120VAC operation but is likely to affect the inverter, especially if it has GFI type sensing on the AC side.

27 days ago

Surge protector is a must. S0 far, this rally season, the group has had two major failures that a surge protector might have prevented.
One individual with a brand new TT, plugged into a 50 amp outlet with an open neutral. Everything that was on the RV that was electrical was impacted.

27 days ago
Reply to  tom

A surge protector is for high energy electrical surges that usually come from nearby lightning strikes. What is more important to have installed on your shore power is an EMS protection system that checks every aspect of the power coming from the shore or pedestal BEFORE allowing it to enter the RV. EMS stands for Electrical Management System so it will check for proper polarity, open neutral or ground, proper Hz level, etc. One of the best devices that I use is from Progressive Industries, the EMS-HW-50C device, which is a hardwire unit. Luckily this very same unit also includes 3580 Joules of Surge Protection.

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