Will my RV gas generator cause problems with my MPPT and Inverter?

[Kzneft]

Wiring up solar panels to my MPPT/batteries, then batteries to inverter. My RV has a gas generator (5500w) that when running will charge my batteries. Will this all be ok or will I have to disconnect when running my generator?
Also what about when I connect to shore power? This is my first solar RV attempt so I want to try to get it right.

 

[offgriddle]

Okay, if this helps, I have a shore power battery charger permanently connected directly to my batteries which charges the batteries when shore power is available.
I have my solar panels connected to the input of my solar charge controller which is permanently connected directly to my batteries which charges the batteries when the sun is out
I have an invertor permanently connected directly to my batteries which I manually switch on and off using the power switch on the invertor.
And everything is fine.

 

[zjr]

Wiring up solar panels to my MPPT/batteries, then batteries to inverter. My RV has a gas generator (5500w) that when running will charge my batteries. Will this all be ok or will I have to disconnect when running my generator?
Also what about when I connect to shore power? This is my first solar RV attempt so I want to try to get it right.

Hi there I'm new to solar power as well, so i hope the expert solar nerds will step in.
#1 The rv disconnect that you show, you have it draw in as a battery disconnect only.
#2 What is the box below the 40 amp mppt, if it is your 12v fuse panel then the negative from the solar input is not right it most come from the battery negative side.
#3 You have no battery negative off the mppt, there is 6 input/output connectors on the mppt, 2 input solar +/-, 2 output battery +/-, 2 load output +/-
#4 The 40 amp fuse not required the 50 amp breaker goes there to protect the mppt, the box (12 fuse panel box ??) move over to the other side of the 50 amp breaker.
#5 As for your gennertor use you need to add a auto transfer switch ( 50 amp or 30 amp ?? ) to go from gen to inverter safely. You may have one in there already to go from gen to shore power, adding a second one to use all 3 gen power, shore power, and inverter power.
#6 Here is link to one Will's. https://www.mobile-solarpower.com/the-minimalist-great-for-small-vans-and-cars.html hope this help's you

 

[Justin Laureltec]

@Kzneft, a few important questions:
1. How exactly is your generator going to charge your batteries? I presume you mean that the generator is providing AC power that is then used to run an AC-DC charger, but since that's not in your diagram I can't tell whether or not it's going to interfere with anything... how all of these things are connected will be critical to establish the proper methodology here.

2. As a general note, 5ga wire is not appropriate for a 2000w inverter at 12v; the appropriate gauge will be determined by the exact length (round-trip) of cable run, but typically it will be somewhere between 2AWG and 2/0 (00) AWG. Again, this is dependent on total cable run.

3. You should have a fuse or breaker at the battery on the line feeding the inverter... before the disconnect switch. Also, for a 2000w inverter at 12v nominal, this will most likely be a ~100A fuse or breaker, not the 50A as shown... but this depends on the cable gauge, as the purpose of the fuse/breaker is to protect your cable, not the inverter.

There are a number of other considerations to be taken into account here, but if we clear up these first few, I think we'll be better-equipped to continue with troubleshooting/advice re the proper way to set up this system.

 

[Ped]

No.

 

[Kzneft]

Thanks for the feedback, it was very helpful, except for Ped. Sorry, put a wire in the wrong place. Does this look better? Similar to Will's layout. If my RV disconnect is only about 4' from the breaker and MPPT would you still use a #2 wire?

 

[zjr]

Hi looking better.

#1 move the inverter +(red wire) closer to battery, the shorter the wire the less the cost per foot, add a fuse at the battery + to protect inverter, sized rated to fit the inverter
#2 are you removing the rv 12v fuse box that exist in rv now, if not you don't need to add an other one, just feed power from your solar battery's back to your existing 12v box. Then you have rewire the AC to DC 12v converter with a 15amp breaker (110v ac breaker in a separate box) removing or disabling the existing breaker in your existing 110v box. This new 110v box needs to be powered off the shore and gen power side, then you run the 12v converter side back to your solar batterys to charge your solar batterys when your on shore or gen power. PS rv power is confusing they have two voltage's(12v and 110v) shore power and gen power now you add solar power into the mix it becomes more confusing. We don't want you burn the rv down for pete's sakes.

Hope this help's you more.

 

[Kzneft]

Hi looking better.

#1 move the inverter +(red wire) closer to battery, the shorter the wire the less the cost per foot, add a fuse at the battery + to protect inverter, sized rated to fit the inverter
#2 are you removing the rv 12v fuse box that exist in rv now, if not you don't need to add an other one, just feed power from your solar battery's back to your existing 12v box. Then you have rewire the AC to DC 12v converter with a 15amp breaker (110v ac breaker in a separate box) removing or disabling the existing breaker in your existing 110v box. This new 110v box needs to be powered off the shore and gen power side, then you run the 12v converter side back to your solar batterys to charge your solar batterys when your on shore or gen power. PS rv power is confusing they have two voltage's(12v and 110v) shore power and gen power now you add solar power into the mix it becomes more confusing. We don't want you burn the rv down for pete's sakes.

Hope this help's you more.

 

[Kzneft]

Thank you so much. That is some great advise ! Yes, the wiring in RV's are a pain, and no schematic either.
Do you know if there is a device that will disconnect the 120v from the inverter that is also connected to the gas generator and shore power? I can't rely on someone disconnecting the inverter if they start the generator. Everyone tells me if I start the generator or connect to shore power it will destroy the inverter if they are all connected to the 120v side.

 

[zjr]

Yes it's call a tranfer switch, Here Will's link to some. https://www.mobile-solarpower.com/automatic-transfer-switches.html Hope this helps.
Your rv may already have one for your shore power to gen, the relay shuts off the dash gen switch when your connected to shore power.
Here some thing else to look at https://www.mobile-solarpower.com/all-in-one-solar-power-packages.html

 

[vtx1029]

You can also use a manual switch like this to do the transfer. https://www.amazon.com/gp/product/B07MZ739CS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[mkaye]

Thanks for the feedback, it was very helpful, except for Ped. Sorry, put a wire in the wrong place. Does this look better? Similar to Will's layout. If my RV disconnect is only about 4' from the breaker and MPPT would you still use a #2 wire?

the size of the wire for the inverter is the total length of the wire from the inverter to the battery and back (not to disconnect) - so red + black
use this https://www.bluesea.com/resources/1437 to calculate wire size

in my class C i don't run the inverter wire through the disconnect, just the 12V going to the DC distribution panel