tomy2
escape artist
So if I ran a ground wire from the load panel ground straight back to the subpanel new ground busbar, that would cure the floating ground? Thanks again for your insights and patience with us wannabe electricians.
AIO Bonding
- Thread starter LSC
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tomy2
escape artist
If subpanels are supposed to have no N and G bond, why are they allowed to sell them with a single busbar.?
Correct.
1) Because some panels sold can be either a sub panel or main panel
2) Panels don't come with everything required (they don't include all breakers for example)
3) Because they can make an extra $6 off you for the separate ground bar!
Side note - the panel I bought to use as my critical loads sub panel was actually intended for a main panel, yet it came with its own separate ground bus bar. I didn't know it would, so I had bought an extra ground bar and now I don't need it. Go figure lol.
Sub panels are also used as a small main service panels as well. Extremely small sun panels you connect the grounds without using the buss bar at all (or add one for convenience)
tomy2
escape artist
Yes a AIO connected with a cord is a problem unless you scale back your charging rate and limit your consumption of power to the difference between the available incoming wattage minus the wattage used for charging
Ok, I got an answer from CHINS and they said that the N & G are NOT bonded together inside the unit. So based on my drawing I should place a connection between the N and G in the AC OUT breaker box? Yes or No? Also I added the gnd rod for the solar array. Is that okay?
Also, does anyone have a comment on the pic in post #20? Would that work or be a bad idea? Thanks
Also, does anyone have a comment on the pic in post #20? Would that work or be a bad idea? Thanks
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Why again are you putting an AC plug on your inverter AC input? Why would you disconnect it? That seems to be a complicating factor for your N-G bond. If that stays connected, you shouldn't have to mess with any other N-G bonding anywhere. But if you disconnect the AC-IN to your inverter (including neutral) then yeah you'll do a N-G bond. But ONLY when that is disconnected.
If you insist on having that plug on your AC-IN, perhaps wire another "N-G Bond plug" that you then plug that into that will create your N-G bond when you are disconnected from the rest of the house. I.E. You unplug from the house input, and plug that into a single "outlet" that has a wire from N to G (and no H connection). That way, you can never have a second N-G bond by accident when it is plugged in to mains power.
If you insist on having that plug on your AC-IN, perhaps wire another "N-G Bond plug" that you then plug that into that will create your N-G bond when you are disconnected from the rest of the house. I.E. You unplug from the house input, and plug that into a single "outlet" that has a wire from N to G (and no H connection). That way, you can never have a second N-G bond by accident when it is plugged in to mains power.
If I understand this exchange properly you at least at times attach your AIO to a house outlet if you bond after the AIO you will end up with to bonded neutrals not good. If you really want/néed to be bonded when off grid you will need to come up with a way to disconnect the of grid bond when you are connected to grid. Is this a camper solar system a solar generator or a system in a building?
How else would I connect to the house power?
I don't plan on disconnecting it. I would like to have that to help charge batteries on those not so sunny days.
I added a disconnect switch, I had an extra battery one, and OFF would be open, and ON would connect N & G when the AC Input is unplugged. The added circuit is in blue. Would this work?
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It is a basement setup for now for brownouts if we have them. Eventually going into an RV which will have a lot of changes to put it in one of those. Another day and time.
You technically should have it wired separately into the circuit panel using the wire size and breaker recommended by the manual. You stood have a cutoff switch close to the AIO in case it must be shutdown in a hurry and to make it convenient and obvious when grid is disconnected from the AIO.
You are running into the same problem I had with my MPP 1012LV-MS. The AC In provides the N-G bond while plugged in ONLY when in AC pass-through. When Inverting, you have NO N-G Bond. I was instructed by Ian at Watts247 to tie the two neutrals together inside the AIO (I used a small jumper wire). This took care of the problem (as long as I never unplug the AC-In). This is why it is recommended to hard-wire it to a dedicated breaker in your panel.
So in my drawing I do have the AC IN going through a breaker, with surge protect, going to the AIO. But you are saying not through a plug? Yes?
So get the AC from a subpanel, through a breaker, then from there to the AC Input breaker box and surge protector?
Yes. Use appropriate size wire and breaker.
Tie the neutrals all together (Incoming neutral to the neutral bus bar in your loads panel, neutral output from inverter to the same bus bar).
Tie all the grounds together (incoming ground to the ground bus bar in your loads panel, ground connection from inverter to the same bus bar).
This will resolve all N-G bonding concerns and prevent floating neutrals.
I like how my Outback is wired - it has a spot for incoming and outgoing neutral, even though in the documentation it mentions there really isn't an "in" and "out" neutral as they are all tied together. But they did it that way to make it logical and easy to understand at a glance.
Tie the neutrals all together (Incoming neutral to the neutral bus bar in your loads panel, neutral output from inverter to the same bus bar).
Tie all the grounds together (incoming ground to the ground bus bar in your loads panel, ground connection from inverter to the same bus bar).
This will resolve all N-G bonding concerns and prevent floating neutrals.
I like how my Outback is wired - it has a spot for incoming and outgoing neutral, even though in the documentation it mentions there really isn't an "in" and "out" neutral as they are all tied together. But they did it that way to make it logical and easy to understand at a glance.
Now I see what everyone is saying. It is all about the plug. I have an unfinished basement and it has one outlet available. That is my dilemma. That is the reason for the plug. There is a subpanel in the basement but it was for a long retired hot tub. The breaker for it outside is shut off. So I am trying to come up with a way to make this as easy as possible but yet safe.
It has a dual 30A breaker outside.
