195RB adding inverter separate from junction box - ground wire?

[John_66bf31462db98]

I am doing a "clean" battery move to a LiFPo 300aH battery and adding an inverter. I'm not connecting the inverter to the power system to avoid dealing with connecting behind walls etc. I'm just bringing the battery cables from the front hitch into the bed compartment and connecting to + and - busbars, which are connected (through fuse and switch and shunt) to the battery. I am connecting a 200w inverter to the busbars, and will run a 30a outlet to the storage door so I can plug in. I know I will have to shut off the charger when using the inverter, but am fine with that.

My question is, there is a ground connection on the inverter. Where should I attach that? I can run a ground wire forward to the junction box, but am not sure where the ground busbar is up front on the existing wiring. I can also possibly connect to the trailer frame, making a new connection.

Any suggestions? I prefer to use existing connections/boxes/busbars if possible. Is there a ground bus underneath somewhere?

 

[John_66bf31462db98]

Typo: 2000w inverter, not 200w

 

[RogerR]

Unless the inverter instructions suggest otherwise I would connect the inverter directly to the battery with cables based on max amps the inverter draws. Any other way may stop the inverter from getting the needed amps and voltage. Look up max draw and figure length (shorter is way better!) and google a chart. Might be 2 or 0 gauge for 2000 watts and under 10 feet. To small and it can overheat or under perform.

 

[John_66bf31462db98]

Unless the inverter instructions suggest otherwise I would connect the inverter directly to the battery with cables based on max amps the inverter draws. Any other way may stop the inverter from getting the needed amps and voltage. Look up max draw and figure length (shorter is way better!) and google a chart. Might be 2 or 0 gauge for 2000 watts and under 10 feet. To small and it can overheat or under perform.

Thanks, I may consider that. I'm using 2/0 cables for all major connections: battery to fuse, to on/off switch, switch to shunt, fuse to bus bar, shunt to bus bar. I figured that should be ok, but will check again. The connections are very short. I didn't want to connect anything else to the batteries since it would throw off the Victron Smart Shunt measurements.

 

[Kevin Cooper]

Welcome to the forum!
At full capacity, the 2000 watts is 166 amps. The steel frame can carry the amperage with no issues, but I personally would take both pos. and neg. cables to it. Less connections to fail and easier to troubleshoot. Please do not forget overcurrent protection on the pos. near the battery. Correct size would be 200 amps unless you absolutely know you will never be connecting 2000 watts of load to it.
Best wishes!

 

[Jayhawk 29]

I am a bit unsure of a couple of suggestions on running the ground wire for the inverter. The inverter connector on my Renogy inverters is pretty tiny to receive a 1 or 2 gauge wire to it. Are you folks suggesting running the ground cable of that size to the battery's main terminal? I don't think I have ever read that, even on the Renogy site.

 

[Kevin Cooper]

I just looked at a Renogy 2000 watt inverter on Amazon. Included are two 3’ 1/0 cables. As this is 12 volts, distance makes for more voltage drop. So, 1/0 would be a minimum copper cable size.

 

[Jayhawk 29]

The inverter has an additional grounding lug, which I was referring to and took it that this was the main discussion. This is separate from the black negative wire used for carrying the 12 volt to the inverter. Yes the factory inverter comes with the two wires. But its rare that you mount the inverter that close to any TT battery mounted on the hitch.

 

[Kevin Cooper]

If you do not have the ground terminal information, a Renogy 2000 watt inverter says to connect it to the metal frame of your RV with a #12 copper conductor.

 

[Jayhawk 29]

If you do not have the ground terminal information, a Renogy 2000 watt inverter says to connect it to the metal frame of your RV with a #12 copper conductor.

That's my setup. But upon reading several of the replies, it was not clear that some were suggesting the dedicated ground lug, separate from the black negative main feed. Its not ground, as I think sometimes this gets misnamed. Thxs

 

[Kevin Cooper]

It is not really ground as you suggest. It is really bonding the equipment to the frame. The frame, when on shore power is bonded by Equipment ground all the way back to the main. That is where a true ground is.

 

[John_66bf31462db98]

Welcome to the forum!
At full capacity, the 2000 watts is 166 amps. The steel frame can carry the amperage with no issues, but I personally would take both pos. and neg. cables to it. Less connections to fail and easier to troubleshoot. Please do not forget overcurrent protection on the pos. near the battery. Correct size would be 200 amps unless you absolutely know you will never be connecting 2000 watts of load to it.
Best wishes!

Thanks for the reply. I have a 200a fuse from the battery and before the busbar.

I am not sure what you mean when you say "personally would take both pos. and neg. cables to it." Are you talking about grounding here? I'm out of context, it seems.

 

[John_66bf31462db98]

If you do not have the ground terminal information, a Renogy 2000 watt inverter says to connect it to the metal frame of your RV with a #12 copper conductor.

I am going to run a wire (probably a #10) from the inverter ground lug to the existing ground in the junction box in the front of the unit. It's already there as a frame ground, and I can use the same routing that I am creating through the RV floor to the front, since I am bringing my battery cables inside that way. Thanks!

 

[RogerR]

Sorry to poorly word my suggestion. I would wire directly inverter to battery if possible. A fuse or breaker in the line is your choice and probably a good idea. Running through the frame or via the MPPT is optional but not ideal. Shorter, less junctions to fail is best.

 

[Jayhawk 29]

I use this style of fuse in my positive red line from the battery to the positive side of the inverter.

https://www.amazon.com/s?k=anl+fuse+block&adgrpid=1337006704563654&hvadid=83563305685622&hvbmt=be&hvdev=c&hvlocphy=56187&hvnetw=o&hvqmt=e&hvtargid=kwd-83563266840307%3Aloc-190&hydadcr=24661_13770088&mcid=4ae26994ae2938278b515d115a3c71ca&msclkid=2d97df0376fb1cc7b7e1b8e649e3f05e&tag=mh0b-20&ref=pd_sl_5gud5jis9n_e

 

[John_66bf31462db98]

Sorry to poorly word my suggestion. I would wire directly inverter to battery if possible. A fuse or breaker in the line is your choice and probably a good idea. Running through the frame or via the MPPT is optional but not ideal. Shorter, less junctions to fail is best.

Thanks Roger. I will consider wiring directly to battery, but with the 2/0 cables to the bus bar and then to the inverter, and the short distances, I think the V loss will be minimal.

I never considered anything but a close connection, so should be ok. I did figure out my grounding question, however.