Dear Dave,
We own a 2022 Winnebago Vista 29V. We are the original owners, purchased three years ago, and now have 39,000 miles and love this RV. Two years ago we changed to Battle Born lithium batteries, changed to the upgraded Progressive Dynamics converter/charger, added a DC/DC charger, and have 200 watts of solar. Everything works GREAT. But my question involves the inverter.
The coach came with the Magnum Dimensions 1000 inverter, as shown. I THINK the battery cable from the inverter to the battery bay is a 1/0 gauge, if I’m reading it correctly. This is a thicker gauge cable than the standard battery cables, and runs to a block mounted in the battery bay. The other lug on the block goes to the house batteries.
If I change out to a 2000-watt inverter, do I also need a heavier gauge cable to the batteries? Thank you. —Anthony, 2022 Winnebago Vista 29V
Dear Anthony,
The gauge wiring or cable depends on the model of inverter that you get, from what I am seeing in different installation manuals. If you stay with Magnum Dimensions and go with their model CSW2012, which is the 2000-watt inverter, their installation guide recommends #3/0 AGW if your cable length is not longer than 5’. From 5′-10’, you would need to go heavier with a #4/0 AGW cable.
Progressive Dynamics inverter
You might also want to consider the Progressive Dynamics model PD1620, also a 2000-watt inverter. They recommend a wire gauge of #2/0 AGW from 0′-10’.
Just as important as cable gauge is proper installation. The CWS2012 requires a DC Overcurrent Protection device. This is installed on the positive DC cable and can be a fuse or circuit breaker. Looking at the chart for the CSW2012, the fuse needs to be 300 amp with time delay. This size fuse or circuit breaker will open before the cable reaches maximum current to prevent a fire. Also, according to the CSW2012 installation manual, NEC code also requires a disconnect switch. They recommend a Class-T fuse, rated for DC operation and the time delay for momentary surges.
According to the Progressive Dynamics installation manual, the PD1600 series inverter, including the PD1620, has an internal under/over voltage protection to protect both the inverter and the battery bank. These voltage limits are designed to operate with a lead-acid battery bank without damaging the batteries. The inverter may also be used with a 12V lithium ion battery pack (LiFePO4) with a properly configured BMS.
Where to mount the inverter
The last thing to consider is where to mount the new inverter. It should be mounted as close to the house batteries as possible. However, if your original batteries were flooded lead acid (FLA), that compartment is vented and exposed to the elements. Your 1000 watt inverter most likely is mounted inside an exterior compartment which is sealed but is probably farther away from the house batteries than the 5′-10’. So you might need to get creative in the location and also consider how to get the 120-volt AC lines to and from it, as well.
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My inverter only powers one outlet. How can I rewire it to add more?
Dear Dave,
I have an inverter in my new camper and despite repeated requests I cannot get a wiring diagram for the camper. The inverter only seems to power one poorly placed plug—not even the one for the shaver in the bathroom! The inverter is basically useless. I’m planning on rewiring it. (I’m the son of an electrician and an electrical engineer—so I probably won’t electrocute myself. 🙂 ) But I wonder why the manufacturer won’t give me an electrical diagram. Apparently even the dealer can’t get one. Any helpful info? Thanks! —Tom, 2021 Heartland Mallard Pathfinder
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Thank you, Dave! 🙂 You never fail to educate me with this column. If only my retention were better. 🙂 Thanks again, have a great week, and safe travels! 🙂
There are no electrical installation diagrams. Each unit is wired in whatever fashion by whatever under paid “hack” they drag off the street. The only thing that is the same is how fast and cheaply it can be done for “piece work prices”.