7.2KW ProPower for Off-Grid Cabin

[Hullguy]

The box is still grounded to the panel -- where would this voltage derive from?

do You have an electrical license?

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[daemonic3]

“if neutral and ground is ohmed out is it zero”. Because it is now an open circuit.

I agree it *should* be an open circuit based on the documentation of the Magnum, I was just curious if he checked that the initial install din't bond it somewhere outside the panel. The fact his propower test with the ground unbonded in the panel worked supports that it was the only place it was bonded.

Also my text you quoted was a question to the OP not a statement. I know what 0 ohms and an open circuit mean, I have an engineering and a physics degree.

“Where there DOES seem to be consensus is that the bonding should only be in ONE place. It seems (based on the PDF file) that the inverter is not doing it. That leaves the propower and panel doing the redundant double bond. So which should be unbonded”. If you use the neutral switching transfer switch there is no thought involved. It just works. If you go into the panel, disconnect the bond from the inverter neutral you have to remember to reattach it when you leave. Now you are in a live panel and risking getting shocked every single time. Why risk it? And the NEC also states that only a qualified person should be in the panel.

The correct transfer switch costs $450. Roughly another $800 for parts, wire, and installation time. Why not spend $1200, do it right and safely, with no thought?

Can you provide a link to this transfer switch? I keep thinking of a neutral switching transfer switch as being 3 or 4-pole and including the hots. If that is the case (switching the hots) then it completely defeats the purpose of his setup. He would either be transfering from inverter to generator and never letting them run together to take advantage of the bidirectional ability the inverter provides to the battery.

So I'm trying to figure out if every time a "neutral switching transfer switch" is suggested is that telling the OP to give up the desired functionality to do this "properly to code" or is there a transfer switch you suggest that ONLY switches neutral.

In the case where it ONLY switches neutral, where do you suggest tapping in? If it is between the inverter and panel, the propower will stell see that ground bond inside the panel.

I'd like to know your suggestion here! I can't see how the OP keeps his existing functionality with your suggestion so I hope I'm missing something. @HammaMan's suggestion still met the OP's main objective: Keep his existing *functionality* of being plug and play with an external generator on his existing setup.

 

[HammaMan]

Yes I have been at code revision discussions. The utility is covered under a different code than dwelling wiring. NESC National Electrical Safety Code. Dwellings are defined in Article 100 of the

I understand what the utility does at the pole. This is to stabilize the voltage coming from the transformer. But that’s not part of the Dwelling or NEC!

A generator for the dwelling is also covered under the NEC. There’s teo types, a floating neutral which is relying on the ground neutral bond at the panel to stabilize and provide short circuit protection.

The other one is a bonded neutral generator which the Powerboost is. This adds a second ground. The truck sees this and determines it’s a fault to ground and trips.

Sorry, it’s not magic, it’s fact! It’s a fact that under the NEC a generator supplying a dwelling IS NOT a utility. Your logic is wrong and not supported by fact. Jim.

That's a whole lot of words to dodge the question entirely. The fact is, however, this is a microgrid and covers variables outside of the scope of the NEC's limited one-size-fits-all approach.

I asked what difference does it make, and the answer is none. You don't get to make up what's safe and what isn't. The fact is that L1, L2, and bonded neutral (moot) being provided by a generator with OCP is safer than utility, which does the exact same, less OCP. You can try to argue with that, which you have, but you haven't contributed to the conversation constructively. Given the panel's wiring as shown, which has not been acceptable under any code variation I'm familiar with, further indicating that there's no code enforcement / inspector in his neck of the woods, your advice should be that of which makes for a safe installation.

The fact of the matter here is that there's only one way to safely connect this system together, and I listed it. It doesn't matter if it's a generator sitting 500 miles away in a dam, or outside in the driveway. While you say it's not magic, I'm beginning to think you actually believe it is. After all if the generator is owned by the utility, it's "safe", but if suddenly the ownership changes to that of the customer, it's not?

 

[HammaMan]

Keep in mind, the L14 cord DOES NOT feed a panel, it feeds the inverter. The inverter feeds the panel. I'd hate for that fact to be lost on the discussion.

 

[daemonic3]

Keep in mind, the L14 cord DOES NOT feed a panel, it feeds the inverter. The inverter feeds the panel. I'd hate for that fact to be lost on the discussion.

I feel that's been lost as well. I'm still curious how a transfer switch allows the OP to preserve the original funtionality, and not defeat the whole purpose. It's not "generator OR inverter" it is "generator to inverter that has bypass and charge capability"

 

[HammaMan]

I feel that's been lost as well. I'm still curious how a transfer switch allows the OP to preserve the original funtionality, and not defeat the whole purpose. It's not "generator OR inverter" it is "generator to inverter that has bypass and charge capability"

Automatic neutral bond disconnect on external power source being present. While it's possible to do this with the generator using a NC contactor, the PPOB will trip before such contactor opens, which is the nature of GFI. GFI by nature must open very fast at a minimum. I'd expect the PPOB inverter being as new as it is to trip within half the time that's required to be GFI compliant.

 

[Hullguy]

I agree it *should* be an open circuit based on the documentation of the Magnum, I was just curious if he checked that the initial install din't bond it somewhere outside the panel. The fact his propower test with the ground unbonded in the panel worked supports that it was the only place it was bonded.

Also my text you quoted was a question to the OP not a statement. I know what 0 ohms and an open circuit mean, I have an engineering and a physics degree.



Can you provide a link to this transfer switch? I keep thinking of a neutral switching transfer switch as being 3 or 4-pole and including the hots. If that is the case (switching the hots) then it completely defeats the purpose of his setup. He would either be transfering from inverter to generator and never letting them run together to take advantage of the bidirectional ability the inverter provides to the battery.

So I'm trying to figure out if every time a "neutral switching transfer switch" is suggested is that telling the OP to give up the desired functionality to do this "properly to code" or is there a transfer switch you suggest that ONLY switches neutral.

In the case where it ONLY switches neutral, where do you suggest tapping in? If it is between the inverter and panel, the propower will stell see that ground bond inside the panel.

I'd like to know your suggestion here! I can't see how the OP keeps his existing functionality with your suggestion so I hope I'm missing something. @HammaMan's suggestion still met the OP's main objective: Keep his existing *functionality* of being plug and play with an external generator on his existing setup.

 

[Hullguy]

Sorry if it looks like I’m trying to be argumentative. I don’t want anyone to get electrocuted because of misinformation or trying shortcuts.
Transfer Switch Link.
http://www.reliancecontrols.com/ProductDetail.aspx?XRC0303DR
The transfer switch replaces the panel. It has circuit breakers. And works with the Pro Power. I have one in my house.
Yes, this transfer switch is a three pole switch.
Yes the transfer switch will not allow the generator to recharge the batteries. The generator supplies power to the house, the batteries charge by the solar panels via the inverter.

Part of the NEC has a “listing and labeling“ clause. Which means on install you must follow the instructions provided by the manufacturer.
From the Magnum Owners Manual, ” All electrical work must be performed in accordance with local and national electrical codes.” This instruction here knocks out any thoughts of trying to treat this as a utility. Jim.

 

[nkgreen7]

Hello,

I've been loooking around the forums and see some discussion about powering a home with the ProPower, the need for a transfer switch, etc. I have an off grid cabin with a solar system and am wondering if there are some cheaper/easier options for me since I'm not connected to the grid? I have a 30A 240V plug that I typically plug into a generator to charge my solar batteries/run the cabin. It faults immediately when I plug into my ProPower.

I've read that I can remove the ground from my cable that goes truck to the solar inverter inside the cabin but not safe. I appreciate any comments/help with this. Thanks.

I have a similar situation hooked up to grid power but to energize the house with my truck I shut off solar system completely and turn off main power to house and then I have a 30 amp inlet in my garage. The key is you have to remove the ground wire on the inlet going to house because the truck and house are both grounded. With a regular generator it doesn't bother it. If you do that it will work. Otherwise you must have a transfer switch installed. Hope this helps.

 

[HammaMan]

The key is you have to remove the ground wire on the inlet going to house because the truck and house are both grounded. With a regular generator it doesn't bother it. If you do that it will work. Otherwise you must have a transfer switch installed. Hope this helps.

A transfer switch will not change a bonded neutral and allow the truck to power the home because of its GFI breaker unless....
1) The neutral to ground bond occurs in front of the ATS
AND
2)The ATS switches L1, L2, AND neutral

 

[JerseyMike]

if there was a way to have an interlock that switches over the ground that might work

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