Feeding whole house 200 amp panel off-grid

[atlsolar]

went ahead and changed up the diagram for this "stupid" method as well as drew the batteries on there.

 

[Zwy]

For the batteries, if you look at the photo the complete circuit (positive and negative cables) to each inverter is the same length. This is why all positives go to one junction box/busbar and all negatives go to the other. This helps keep battery voltage to each inverter the same. I do mine the same but use a Victron Lynx busbar which is rated to 1000A. Location of batteries to inverters does play into this and equal lengths may not always be possible but something to keep in mind. If batteries are directly below the inverters, then it is easy to install as shown in the photo.

I do like your latest diagram. There should be an EGC to the batteries if batteries are metal cased. The EGC goes to the metal case only. This is to ground the metal cases to clear a ground fault and prevent electrical shock if the metal case became energized with AC.

 

[cocoabill]

I know this thread is a little old, but it’s dealing with what I’m trying to do right now on my system and I need some clarification. I’m installing two Schneider XW pros in an off grid system. I have a 200 amp 60 breaker service panel. My plan was to just run the output of the Schneider’s directly into the service panel using 60 amp breakers. I like the idea of having the 200 amp unused breaker at the top of the panel in case somebody in the future wants to go on grid although at the $14,000 hook up cost it’s not for me. Is this a legitimate way to hook this up while still keeping it compliant with any C code?

 

[CaliSunHarvester]

Stove 40amp
Dryer 30amp

Stove is on 40A wire/ breaker but pulls probably 27A (wire 20% oversized for continuous use)

Dryer probably pulls 20A

 

[BentleyJ]

You may use 2 x 60A breakers to feed the main panel in an off-grid system. Since its AC, the breakers are bi-directional and its acceptable to back-feed them. This is exactly how grid-tie systems are connected to a breaker panel with back-feed breakers.

As far as future utility connections, this can be added. It would be necessary to add a fusible 200A, double throw safety switch which will either direct power to the Inverters AC1 inputs or to the main breaker on the panel. In this sense the double throw safety switch becomes a means of disconnect, an over current protection device and a maintenance bypass.

Alternatively, there are breaker interlock kits that prevent the main breaker from being on at the same time as one of the top breakers. These are often times used to add a back-up generator or a battery back up inverter to the main panel. Problem with these interlocks is they only extend down to the first top breaker on one side or the other.

 

[Zwy]

I know this thread is a little old, but it’s dealing with what I’m trying to do right now on my system and I need some clarification. I’m installing two Schneider XW pros in an off grid system. I have a 200 amp 60 breaker service panel. My plan was to just run the output of the Schneider’s directly into the service panel using 60 amp breakers. I like the idea of having the 200 amp unused breaker at the top of the panel in case somebody in the future wants to go on grid although at the $14,000 hook up cost it’s not for me. Is this a legitimate way to hook this up while still keeping it compliant with any C code?

A few of us members are running SRNE ASP inverters which don't have a breaker on the output plus a way was needed to combine output of each inverter as each inverter output has a max wire size of 6AWG. The solution for a pair is to use a combiner box with a pair of backfed breakers, then run a larger AWG wire to the loads breaker panel thru either another backfed breaker with a hold down kit or into the main 200A breaker. I found the Eaton 125A box to work very well for this purpose as it can have a breaker hold down on both sides. I show it wired at this point in my build videos.Note the screw in each breaker, that is the hold down for the Eaton BR breakers which is better than SQ D QO even though I prefer SQ D. The Eaton is very reasonable in price, breakers are cheap and common and the hold down kits are very reasonable compared to SQ D.

Part number is shown at this point in part 1 of the series and I show how the hold down kits.

 

[cocoabill]

Impressive system.

I'm having another look at my inverter outputs which are located in the Schneider power distribution panel PDP. It looks like they have the loads already tied together. I'm thinking I should actually run a 1 gauge to my main panel.

I'm taking inspiration from David Poz system on YouTube unfortunately he is a bit Vague on what he does in this area. I have attached a picture of what PDP looks like. Am I missing anything?
I appreciate the feedback!

 

[Zwy]

Yes. according to that photo, the outputs would be combined using a common busbar with lugs on the breaker outputs. No need to combine strings elsewhere. As for wire size, I did upgrade to 1AWG from the required 2AWG. Output of each XW is around 7kw so you might be able to use 2AWG. My reason for 1AWG was if in the future I installed larger inverters, the wire was already run plus it is 45 feet to the loads panel from the inverters.