7.2KW ProPower for Off-Grid Cabin

[Hullguy]

This is becoming overly complicate! It all comes down to the off the grid systems ground and the Powerboost adding a second ground!

The installation manual, (https://www.magnum-dimensions.com/file/2414/download?token=jvCyRGs3), page 13, shows the grounds from the batteries, solar arrays, and AC source having all the grounds landed together!

This becomes the same issue as trying to use the Powerboost to power a on the grid house! You need a neutral switching transfer switch!

The inverters OT66 was using set all floating grounds. Which is why they worked.

Once again, I highly recommend NOT using a device to lift the Powerboost ground. You are defeating the safety’s if you do so

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[Gros Ventre]

Very cool find! The pass thru makes a ton of sense. I missed in the feature set of the inverter that it has that AC input and pass thru, and is bidirectional to the battery.

I now wonder what the solution would be. Add a switch in that sub panel to unbond the neutral for propower use, and let the truck bond it?

The rule is one neutral ground bond. So letting the truck system do that will work. This then removes the "neutral-ground" that the truck senses causing the shutdown. You should still have the building's ground wire properly "earthed" somewhere in/around the building.

 

[jeffcrum]

The rule is one neutral ground bond. So letting the truck system do that will work. This then removes the "neutral-ground" that the truck senses causing the shutdown. You should still have the building's ground wire properly "earthed" somewhere in/around the building.

The truck won't always be there. So, not a good idea.

This might actually be the perfect situation for the neutral switching transfer switch with the small number of circuits.

 

[EricR]

You might find some useful feedback if you post here:

https://diysolarforum.com

 

[mj1angier]

So I do what you are trying to do at my cabin. It appers you have a charger/ inverter simmilar to what I have
https://www.amazon.com/AMPINVT-Inve...R&qid=1662731602&s=merchant-items&sr=1-2&th=1

I can feed it with battery or shore power ( shore power being a genny). The batteries are also hooked to a solar controller to be charged by panels. My genny had a 3 blade RV outlet so that is the plug I have on the cable. I got a dog bone adapter and just plug into the 115 v plug in the truck.

The shore power is used 1st to feed cabin and then charges batteries. Depending on what the demand is, the batteries get topped of pretty quick. I have lithum battries so I can draw them down deep before needing to recharge if solar does not keep up.

 

[OT66]

So I do what you are trying to do at my cabin. It appers you have a charger/ inverter simmilar to what I have
https://www.amazon.com/AMPINVT-Inve...R&qid=1662731602&s=merchant-items&sr=1-2&th=1

I can feed it with battery or shore power ( shore power being a genny). The batteries are also hooked to a solar controller to be charged by panels. My genny had a 3 blade RV outlet so that is the plug I have on the cable. I got a dog bone adapter and just plug into the 115 v plug in the truck.

The shore power is used 1st to feed cabin and then charges batteries. Depending on what the demand is, the batteries get topped of pretty quick. I have lithum battries so I can draw them down deep before needing to recharge if solar does not keep up.

Thank you for your reply. So you think that if I switch my system from 240V to 120V that it's going to work? Can you explain to me why it would ground fault at 240 but not at 120?

 

[mj1angier]

Thank you for your reply. So you think that if I switch my system from 240V to 120V that it's going to work? Can you explain to me why it would ground fault at 240 but not at 120?

So I am not sure. It depends on what your inverter/charger is made to take as shore power. Mine is set up for 120v.

 

[OT66]

So I am not sure. It depends on what your inverter/charger is made to take as shore power. Mine is set up for 120v.

Mine can do both. When I got the cabin it was setup 120 only, and I changed it to 240 however I don't have any 240 plugs in the cabin so I'm not sure I really need it other than I was told it's easier/better for the generator to be setup that way since it runs off both legs (hots). Does that make any sense?

 

[mj1angier]

So I looked at the generators you said you used and only one had 240 output I think. The others had 120v 30a plugs. I might be wrong ( wife tells me i am a lot so it must be true) I feel like you might be pushing 240 into 120. Again just going by what I can see from google photos of gennys and not know exact models.

Look at the plugs on this Firman 3500, they are all 120v
https://www.electricgeneratorsdirect.com/Firman-Generators-P03608-Portable-Generator/p106122.html

 

[Snakebitten]

I have the Yamaha 3000 inverter generator. It's a wonderful piece of equipment. But it too is a 120V 30A output.

I suspect the Yamaha 6000 might have 240 for obvious reasons.

Edit : the 6300 inverter generator is indeed 120/240

 

[Yves]

Thank you for your reply. So you think that if I switch my system from 240V to 120V that it's going to work? Can you explain to me why it would ground fault at 240 but not at 120?

I would bet that it will still ground fault. As mentionned earlier, neutral can only be bonded at one place. So if you use 120V or 240V it's irrelevant.

 

[OT66]

I would bet that it will still ground fault. As mentionned earlier, neutral can only be bonded at one place. So if you use 120V or 240V it's irrelevant.

Ok, that's what I thought too. Thanks.

 

[Yves]

Mine can do both. When I got the cabin it was setup 120 only, and I changed it to 240 however I don't have any 240 plugs in the cabin so I'm not sure I really need it other than I was told it's easier/better for the generator to be setup that way since it runs off both legs (hots). Does that make any sense?

Normally panel have 2 legs (black and red wires and white is common), if you want to take advantage of it then you need to run 240V to your panel. If you have a chance to follow your L14-30 and see where it is connected it would be great.

 

[OT66]

Right, so my panel has the black and red ran to it from the inverter. When I got the place, only the one hot (black or red I forget) was hooked into the inverter input and the second was capped and set aside. That's because the previous owners only had a 120v generator. When I got one with a 240 plug I decided to hook up the second hot, so that I could run 240. I have traced my L14-30 plug. It goes directly into my Magnum inverter. What I was told earlier today speaking with someone at Magnum is that I need to take the ground wire coming from that plug and attach it to ground screw on the inverter. He thinks that it's likely not connected currently and that will solve the issue. I am not sure about this but I'll check it out this weekend when I'm there and hope that's all it is.

 

[Yves]

Perfect. I don't know if you have notice but several of us are retired....so a few pictures may help to understand better

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