Factory solar package charging question

[GDRV-Megan]

The sub-panel only has the general circuits that runs off the solar.
I don’t have any pictures. Here is the drawing, that might help.

[howson]

Here is the drawing, that might help.

Perfect! Thanks, Megan.

It's easy to see what will not run off the inverter--everything that's on the main panel (microwave, dryer, A/Cs, water heater, washer, dishwasher, etc).

For what's on the sub-panel, the GFCI circuit is typically the island kitchen outlets, bathroom outlet(s) and pass-thru outlets.

"Gen 1" and "Gen 2" are likely the non-GFCI living room and bedroom interior outlets. The living room, at least in my 315RLTS, includes the outlet that powers the refrigerator.

There definitely will need to be some expectation management done with owners that have the 2000W inverter. I'm not an engineer, but my back-of-the-napkin math suggests the inverter will not even come close to providing all the power the sub-panel circuits are capable of handling. 2000W/120V=~17amps. The sub-panel has three 15 amp breakers, or potentially up to 45 amps. In other words, it will be very easy for an owner to overload the inverter.

Am I reading this right TucsonJim , Jkwilson or any of the other multiple forum members here who are dialed in to this stuff?

[OffToHavasu]

So 2000w perfectly would equal to 16.6 amps. So you'd have to go to 15. Per NEC you're allowed 13 outlets per circuit (yeah I know NEC vs RV). But technically it's not one circuit because it's on a sub-panel. So technically everything is fine, you just have watch your load.

Example: You can have 100 circuits on a 50 amp sub panel in your home. As long as you're under on your load amps, you're fine.

This setup does allow for easy upgrades though.

[Glamping4two]

Perfect! Thanks, Megan.

It's easy to see what will not run off the inverter--everything that's on the main panel (microwave, dryer, A/Cs, water heater, washer, dishwasher, etc).

For what's on the sub-panel, the GFCI circuit is typically the island kitchen outlets, bathroom outlet(s) and pass-thru outlets.

"Gen 1" and "Gen 2" are likely the non-GFCI living room and bedroom interior outlets. The living room, at least in my 315RLTS, includes the outlet that powers the refrigerator.

There definitely will need to be some expectation management done with owners that have the 2000W inverter. I'm not an engineer, but my back-of-the-napkin math suggests the inverter will not even come close to providing all the power the sub-panel circuits are capable of handling. 2000W/120V=~17amps. The sub-panel has three 15 amp breakers, or potentially up to 45 amps. In other words, it will be very easy for an owner to overload the inverter.

Am I reading this right TucsonJim , Jkwilson or any of the other multiple forum members here who are dialed in to this stuff?

According to this video from grand design it was suppose to power microwave and refrigerator as well.

https://youtu.be/H_5Mn1v7K_A

[howson]

According to this video from grand design it was suppose to power microwave and refrigerator as well.

https://youtu.be/H_5Mn1v7K_A

Well...according to that schematic the inverter won't power the microwave. It's not powered through the sub-panel. Refrigerator, yes.

This is all new to GD, so I suspect there will be a learning curve here. Perhaps there is a different configuration for different models. The Solitude, Momentum, and Reflection lines all have different people in charge, so who knows? If they ARE all wired as shown in the posted diagram, my .02 is that once folks find out they can't run their microwave off the inverter there will be an outcry and the configuration will change.

But changing the circuit to allow the microwave to run off the inverter will require a slightly larger inverter, and battery setup, because with the refrigerator running (compressor working) and the microwave powered on it will overwhelm a 2000W inverter. 2000W, as I believe OffToHavasu pointed out, is 16.67A of 120vAC (2000/120). From my Reflection's manual:



You can do the math.

Obviously a person with an "RV" (Dometic/Norcold) refrigerator can run off propane and the microwave will run fine on a 2000W inverter if they have a sufficient battery bank. Even a single 100aH Battle Born lithium is limited to ~100amps of sustained output, which inverted is 10A of 120vAC. (Head spinning yet?)

Yet another concern I've mulled over is the GFCI-protected outlet on the inverter. Remember, I'm not an engineer, but I've done my fair share of reading and I think GD is going to run into another issue with this configuration. The output of the inverter has a GFCI-protected NEMA outlet and GD is wiring it into a circuit that also has a GFCI circuit (kitchen island, bathroom and pass-thru outlets). That's asking for "ghost" GFCI issues (GFCI pops when it senses an inbalance). Do a google search and you'll see a lot of GFCI-related problems with inverters using GFCI-protected outlets. (I *think* it's mandated by code that a NEMA outlet must be GFCI protected on an inverter, thus my Victron's connection, a lug post, is NOT GFCI protected.)

Not everyone sees GFCI problems. Even the exact same trailer made side-by-side on the production line. One may have the problem and one may not. Each trailer's wiring could cause slight differences in how an inverter's GFCI outlet reacts (due to slight resistance differences in grounds, connections, etc).

I hope I'm wrong about all of this. If I am wrong...well, won't be the first time and I'll be glad if it works out that way.

GDRV-Megan -- would love to hear from a GD engineer that I don't know what I'm writing about and explain why. I don't have an ax to grind here, just trying to help prospect owners with expectation management of their GD-installed inverter.

[Glamping4two]

Well...according to that schematic the inverter won't power the microwave. It's not powered through the sub-panel. Refrigerator, yes.

This is all new to GD, so I suspect there will be a learning curve here. Perhaps there is a different configuration for different models. The Solitude, Momentum, and Reflection lines all have different people in charge, so who knows? If they ARE all wired as shown in the posted diagram, my .02 is that once folks find out they can't run their microwave off the inverter there will be an outcry and the configuration will change.

But changing the circuit to allow the microwave to run off the inverter will require a slightly larger inverter, and battery setup, because with the refrigerator running (compressor working) and the microwave powered on it will overwhelm a 2000W inverter. 2000W, as I believe OffToHavasu pointed out, is 16.67A of 120vAC (2000/120). From my Reflection's manual:



You can do the math.

Obviously a person with an "RV" (Dometic/Norcold) refrigerator can run off propane and the microwave will run fine on a 2000W inverter if they have a sufficient battery bank. Even a single 100aH Battle Born lithium is limited to ~100amps of sustained output, which inverted is 10A of 120vAC. (Head spinning yet?)

Yet another concern I've mulled over is the GFCI-protected outlet on the inverter. Remember, I'm not an engineer, but I've done my fair share of reading and I think GD is going to run into another issue with this configuration. The output of the inverter has a GFCI-protected NEMA outlet and GD is wiring it into a circuit that also has a GFCI circuit (kitchen island, bathroom and pass-thru outlets). That's asking for "ghost" GFCI issues (GFCI pops when it senses an inbalance). Do a google search and you'll see a lot of GFCI-related problems with inverters using GFCI-protected outlets. (I *think* it's mandated by code that a NEMA outlet must be GFCI protected on an inverter, thus my Victron's connection, a lug post, is NOT GFCI protected.)

Not everyone sees GFCI problems. Even the exact same trailer made side-by-side on the production line. One may have the problem and one may not. Each trailer's wiring could cause slight differences in how an inverter's GFCI outlet reacts (due to slight resistance differences in grounds, connections, etc).

I hope I'm wrong about all of this. If I am wrong...well, won't be the first time and I'll be glad if it works out that way.

GDRV-Megan -- would love to hear from a GD engineer that I don't know what I'm writing about and explain why. I don't have an ax to grind here, just trying to help prospect owners with expectation management of their GD-installed inverter.

Agreed and good info. I’ve talk to you before and I am fighting an issue with my microwave currently. It trips the GFCI on the inverter. My inverter is a 3000 watt unit. Batteries are 440 something (don’t remember exact) AGM batteries. I have more diagnosing to to when I can get home once weather breaks here. I want lithium bad but can’t pull trigger on 2k yet. Trying to decide if I want to add a sub panel instead of feeding entire main panel through a transfer switch. As you know the inverter only has one hot so I’m jupering from L1 L2 in the transfer switch to power entire coach. Not sure if separating and creating an inverter panel (sub panel) would help the issue.

Take a look at the Drawing Megan shared. Where is the leg off of the Transfer switch going to on the main panel? To me it looks like it just stops.

[howson]

Agreed and good info. I’ve talk to you before and I am fighting an issue with my microwave currently. It trips the GFCI on the inverter. My inverter is a 3000 watt unit. Batteries are 440 something (don’t remember exact) AGM batteries. I have more diagnosing to to when I can get home once weather breaks here. I want lithium bad but can’t pull trigger on 2k yet. Trying to decide if I want to add a sub panel instead of feeding entire main panel through a transfer switch. As you know the inverter only has one hot so I’m jupering from L1 L2 in the transfer switch to power entire coach. Not sure if separating and creating an inverter panel (sub panel) would help the issue.

Take a look at the Drawing Megan shared. Where is the leg off of the Transfer switch going to on the main panel? To me it looks like it just stops.

Aha! I'd forgotten that was you that had the GFCI problem. Conversing about your issue is where I learned about the GFCI/inverter problem. I look forward to reading your posts when you get to troubleshoot further--please hit me up when you get to it. Would enjoy collaborating and if I can be of any help I'd certainly like to do that, too.

With at least two AGM batteries in parallel and a 3000W inverter I'm pretty sure you have plenty of capability to run a microwave. (I'm not very knowledgeable about AGM battery capabilities.) The issue is the GFCI NEMA outlet on that inverter running into a circuit. (In your case it's not even a second GFCI protected circuit!) But no need to rehash that whole conversation here. Original thread here for those interested: https://gdrvowners.com/forum/solar/7603-inverter-issue

For your sub-panel conundrum, as you (probably) know I wired to the main panel, and both 50A legs of the panel have access to my 3000W inverter. Whether an inverter is wired through a sub-panel or main panel, energy-management is still required. My wife is getting quite the education about power management. She's almost as fluent as me at this point as to what (and why) appliances she can run at any one time when on the inverter.

What I suspect is happening in the diagram is power to the transfer switch (and subsequently to the inverter) is tapped after a 50A main, but not sure which leg, even though that's hard to see in the drawing provided. If shore power is available the transfer switch applies 120vAC to the sub-panel from shore power. If shore power is not available, the transfer switch provides 120vAC from the inverter (via battery power).

[315RLTSinPA]

Both.

However...

The solar panel(s) will only provide amperage based on the amount of sunshine reaching them. (Call me Capt Obvious.)

What is provided by our Fords through the 7-pin is pitiful. I've documented this issue on a thread (as I know you know since you've chimed in on it!): https://gdrvowners.com/forum/operati...e-battle-borns

Bottom line: IMHO you need enough battery capacity to keep the refrigerator running as if you had 0 amps coming from solar and/or the truck for an entire travel day. ("Travel day" is your interpretation--for me it was 10 hours, or the time from shore power disconnect to shore power reconnect.)

My truck does half decent charging the batteries. I've never checked the amperage, but it puts out 14.1 volts to the batteries.

[howson]

My truck does half decent charging the batteries. I've never checked the amperage, but it puts out 14.1 volts to the batteries.

It would be very interesting to know what a pre-'17 SuperDuty sends to the batteries (amperage).

[TucsonJim]

It would be very interesting to know what a pre-'17 SuperDuty sends to the batteries (amperage).

Howard - When towing back from Las Vegas a couple of weeks ago, I did a quick check on my 712 meter. The difference in amperage with the truck running and the truck turned off was about 5.5 amps. I need to run the batteries down to about 50% SOC and repeat the experiment with everything turned off.

Jim

[pengle]

What I suspect is happening in the diagram is power to the transfer switch (and subsequently to the inverter) is tapped after a 50A main, but not sure which leg, even though that's hard to see in the drawing provided. If shore power is available the transfer switch applies 120vAC to the sub-panel from shore power. If shore power is not available, the transfer switch provides 120vAC from the inverter (via battery power).

I recently did a power audit on my 2021 310GK and Howard's description is based on the wiring diagram. The 12/G wire from the Main Panel to the Transfer Switch is actually coming from the 20 amp circuit breaker marked Sub Panel. Then, like Howard said, "If shore power is available the transfer switch applies 120vAC to the sub-panel from shore power. If shore power is not available, the transfer switch provides 120vAC from the inverter (via battery power)." to the Sub Panel box with the 3 circuit breakers in it. Here is a map of which circuits get that power.

[pengle]

Yet another concern I've mulled over is the GFCI-protected outlet on the inverter. Remember, I'm not an engineer, but I've done my fair share of reading and I think GD is going to run into another issue with this configuration. The output of the inverter has a GFCI-protected NEMA outlet and GD is wiring it into a circuit that also has a GFCI circuit (kitchen island, bathroom and pass-thru outlets). That's asking for "ghost" GFCI issues (GFCI pops when it senses an inbalance). Do a google search and you'll see a lot of GFCI-related problems with inverters using GFCI-protected outlets. (I *think* it's mandated by code that a NEMA outlet must be GFCI protected on an inverter, thus my Victron's connection, a lug post, is NOT GFCI protected.)

And Howard is right on with this GFCI issue. I've got two Battle Born 100ah batteries. I leave my Inverter on all the time. At night, if the shore power goes out, the inverter will kick in and keep the refrigerator running on AC and the electric blanket will still heat. OCCASSIONALLY, when I get ready to move from one site to the next, I find that the GFCI circuit on the Inverter has tripped and I have to reset it so that the fridge runs on AC while we are on the road. I don't know WHY it has tripped and I can't figure out what to do to force it to trip so that I can solve the problem. For now, it seems like having two GFCI breakers on the same circuit may be suspect.