Suggested fuse/breaker size given an Inverter wattage

[Mikec557]

I'm going to install an inverter into a newly acquired rv. I think on my last rv I may have gone overkill and upsized the inverter to a size far greater than I needed or would have a use for. The realistic goal of use is this: cpap, electric mattress pad, TV and blu-ray player. I guess in theory all three/four may be on at once, but that is extremely unlikely. I want to use an inverter with automatic power transfer because three outlets in the couch are already wired to a loop of romex in the pass through. The three outlets are all on one breaker in the main breaker/fuse box. If I put an inverter with APT at that loop of romex, the three outlets will always be powered whether on shore power or when the inverter is on.

All that said, I would ask what size fuse/breaker should I use given a 600 watt inverter APT, a 1000 watt inverter APT, or a 1500 watt inverter APT?

I can just about guarantee I won't be putting in a 1500 watt inverter but I thought I should add it to the question because one of the three outlets is in the kitchen. The inverter will be located approximately 4-5 feet from the batteries, two Battleborn 100ah lithiums.

Suggestions on the wire gauge size for each would also be appreciated.

Thanks
Mike

[howson]

I'm going to install an inverter into a newly acquired rv. I think on my last rv I may have gone overkill and upsized the inverter to a size far greater than I needed or would have a use for. The realistic goal of use is this: cpap, electric mattress pad, TV and blu-ray player. I guess in theory all three/four may be on at once, but that is extremely unlikely. I want to use an inverter with automatic power transfer because three outlets in the couch are already wired to a loop of romex in the pass through. The three outlets are all on one breaker in the main breaker/fuse box. If I put an inverter with APT at that loop of romex, the three outlets will always be powered whether on shore power or when the inverter is on.

All that said, I would ask what size fuse/breaker should I use given a 600 watt inverter APT, a 1000 watt inverter APT, or a 1500 watt inverter APT?

I can just about guarantee I won't be putting in a 1500 watt inverter but I thought I should add it to the question because one of the three outlets is in the kitchen. The inverter will be located approximately 4-5 feet from the batteries, two Battleborn 100ah lithiums.

Suggestions on the wire gauge size for each would also be appreciated.

Thanks
Mike

Mike,
Are you asking for the size of the 12v wires that run from the Battle Borns (BBs) to the inverter (whichever one you choose)? That answer is simple--the largest wire size the inverter will accept. Larger wire=less loss. Good, quality welding wire with copper lugs installed correctly. Not sure I'd use 4/0 wire with a 600W inverter, though. That may be way oversizing, especially on a short run.

For the fuse/breaker, that (I think) is driven by the wire size. You always want the fuse (or c/b) to give up before the wire does. If the wire is much more capable than what you'll be pulling, size your fuse or c/b accordingly.

I know this isn't very specific. That's because each manufacturer will have specific recommendations based on their unit and installation particulars. For example, I randomly went to Western Marine and selected a 600W inverter (ended up to be a Xantrex). The manual has the following chart for wiring on page 10:




I guess what I'm trying to say is choose the device, then the installation location and the wiring/fuse will be easy to determine as the manufacturer will likely have specific guidance.

BB is also a great resource! They are super helpful and will talk with you about a proper inverter selection based on your battery bank and usage.

Howard

[Mikec557]

Mike,
Are you asking for the size of the 12v wires that run from the Battle Borns (BBs) to the inverter (whichever one you choose)? That answer is simple--the largest wire size the inverter will accept. Larger wire=less loss. Good, quality welding wire with copper lugs installed correctly. Not sure I'd use 4/0 wire with a 600W inverter, though. That may be way oversizing, especially on a short run.

For the fuse/breaker, that (I think) is driven by the wire size. You always want the fuse (or c/b) to give up before the wire does. If the wire is much more capable than what you'll be pulling, size your fuse or c/b accordingly.

I know this isn't very specific. That's because each manufacturer will have specific recommendations based on their unit and installation particulars. For example, I randomly went to Western Marine and selected a 600W inverter (ended up to be a Xantrex). The manual has the following chart for wiring on page 10:




I guess what I'm trying to say is choose the device, then the installation location and the wiring/fuse will be easy to determine as the manufacturer will likely have specific guidance.

BB is also a great resource! They are super helpful and will talk with you about a proper inverter selection based on your battery bank and usage.

Howard

That's great insight Howard, I appreciate it. I saw on a (insert different RV manufacturer name here) just like my situation that they used a xantrex freedom X 1200 pure sinewave. That's probably a little more wattage than I need, but the unit fit in, and wired up, nicely in the pass-through. But I didn't pay attention to the wire gage used. I think I'll hunt down that user manual and see what it says, or maybe that page you posted will tell me. I need to study that.

Thanks again
Mike

[gbkims]

Xantrex has the recommended DC fuse and wire sizes. Minimum 2 Awg, 150A DC Fuse.
Freedom X 1000 Inverter http://www.xantrex.com/documents/Pow...Rev-F)_ENG.pdf

Xantrex's other inverters:
Inverter DC Fuse Wire
600W 80A 4 Awg
1000W 150A 2 Awg
1500W 200A 1/0

[howson]

Xantrex has the recommended DC fuse and wire sizes. Minimum 2 Awg, 150A DC Fuse.
Freedom X 1000 Inverter http://www.xantrex.com/documents/Pow...Rev-F)_ENG.pdf

Xantrex's other inverters:
Inverter DC Fuse Wire
600W 80A 4 Awg
1000W 150A 2 Awg
1500W 200A 1/0

You never cease to amaze me, Gene!

[Mikec557]

Xantrex has the recommended DC fuse and wire sizes. Minimum 2 Awg, 150A DC Fuse.
Freedom X 1000 Inverter http://www.xantrex.com/documents/Pow...Rev-F)_ENG.pdf

Xantrex's other inverters:
Inverter DC Fuse Wire
600W 80A 4 Awg
1000W 150A 2 Awg
1500W 200A 1/0

Thanks Gene
I think I'm leaning toward this Xantrex. It's a little more than I was hoping to spend, but it's ease of installation is worth a lot to me too. I notice that I see two models too closely similar... the Freedom X 1000 and the Freedom X 1200. I think both are true sine wave and both are NOT chargers. It must be that one of the models is discontinued. Either way, 1000 or 1200, is more than enough.

Thanks