Beginning installation of Schneider XW Pro/EG4ll batteries V1/MPPT 100A 600V OFF-GRID only questions

[SniperX]

I use an external transfer switch to allow for total disabling of the inverter system.
I don't really use the bypass breakers in the PDP

Exactly the same reason I wanted to keep mine wired into the system.

 

[SniperX]

Oh there you go then. I just went and looked at my XW+ and realized I have the top lug too, it's actually a lug that is attached to the XW.

In that case, you could rearrange yours like Ben's, but tbh I kind of like your setup more, so that the transfer switch and the XW are on the same bus bar. I do not think it matters much though, the ground bar and the ground lug in the PDP are legitimately connected by it's chassis, so your preference.

You are the best. Thanks for helping me so much.

 

[SniperX]

2) I would go with a 250A fuse.

Just revisiting the beginning of the thread because some days I can understand things and others I am lost. lol
If I use the 250A fuse, would I need to change my wire size of 4/0 going to the fuse holder? I know 4/0 carries way more Amperage than the 250A fuse, but I hear everyone say you fuse for the wire. Can I keep the 4/0 and use the 250A T-class fuse or should I change my wire to 1/0? I am going from that T-Class fuse to a cut-off switch, then to breakers, and then to the inverter.
First picture shows the fuse mounted but not finished.
Second photo shows the attachment to the busbar.
Third photo shows me trying to figure out how to go from that T-class fuse to a breaker and then to busbars so I can disconnect before it gets to the inverter in case I need to disconnect the batteries and move them vs doing it at the inverter. Would be using 4/0 wire, so I need a lot of room to avoid harsh bends.
Fourth photo shows close-up of cut off switch I originally intended to use with Growatt 12kw
Fifth photo shows it is described as a DC switch
Sixth/Seventh photo shows the Fupact I acquired in a marketplace purchase that they threw in everything and a kitchen sink!
I have a FUPACT but can't find anything on that although I understand it is a cut-off switch too. I have 2 new ones and a used one already loaded with 3 250A breakers.
What would you do?

 

[robbob2112]

You size your wire for the current expected now or in future. You fuse to protect the wire from melting or overheating.

It is OK to have oversized wire if it fits the space and follows the minimum bend radius for the wire. Usually that is the physical size of the wire. i.e. if the wire is 1/2" round then you can't bend tighter turns than 1/2". If you need to bend tighter than that you are doing something wrong.

You go down in wire size to save cost, make it fit the connection point, and/or make it easier to bend for install. You just never go below expected current plus 20%. And your fuse is 25% over max ampacity of the wire.

Class T and other "fast" fuses can allow current to 2 time rated capacity for several minutes. To blow fast they need 6 times rated limit. This means they don't blow for motor starts or other impulses the are more than capacity. But, a wire short will pull many times rated capacity for a short time until the fuse blow. For class T at 6 times rated capacity the blow time is 0.1 to 0.01 seconds. Which depending on amps that can come to the point of the short and the length of the wire may mean the wire isn't even warm. Or it can mean the wire is red hot and if given a few more fractions of a second the sheath would melt.

 

[SniperX]

You size your wire for the current expected now or in future. You fuse to protect the wire from melting or overheating.

It is OK to have oversized wire if it fits the space and follows the minimum bend radius for the wire. Usually that is the physical size of the wire. i.e. if the wire is 1/2" round then you can't bend tighter turns than 1/2". If you need to bend tighter than that you are doing something wrong.

You go down in wire size to save cost, make it fit the connection point, and/or make it easier to bend for install. You just never go below expected current plus 20%. And your fuse is 25% over max ampacity of the wire.

Class T and other "fast" fuses can allow current to 2 time rated capacity for several minutes. To blow fast they need 6 times rated limit. This means they don't blow for motor starts or other impulses the are more than capacity. But, a wire short will pull many times rated capacity for a short time until the fuse blow. For class T at 6 times rated capacity the blow time is 0.1 to 0.01 seconds. Which depending on amps that can come to the point of the short and the length of the wire may mean the wire isn't even warm. Or it can mean the wire is red hot and if given a few more fractions of a second the sheath would melt.

Thank you so much for the explanation. I hope, in future, newbies will come to this thread. So many of you dropped in and explained things. I appreciate it. I figured 9000W in-rush (give or take) /48V= 187.5 X 1.25=234ish. 250A is perfect, I was just unsure If I needed to size down the wire. So glad that @BentleyJ suggested to go down on the Class T fuse.

 

[400bird]

I'm fairly confident the XW manual calls for 4/0 and 250 fuse/breaker for a single inverter. So that's what I went with.

On that mystery 5th relay, it may disconnect the internal transformer neutral connection when grid connected.

 

[SniperX]

Yes, Would recommend putting Neutral on the intended lug. Keeps things looking like a conventional system. The Green screw is the N-G bond. You will need to decide if you want that in the breaker panel or in the Inverter. I believe the Schneider has a dynamic N-G bond via a relay that closes when power is lost on AC1, which is always true in your off-grid situation.

Revisiting an earlier comment regarding L1 & L2. 400bird is correct in that it doesn't matter if the legs get reversed somewhere in the system but down the road its much easier to trace back problems if black and red are consistently used as L1 & l2 respectively.

Can we talk about the N-G bond and the green screw?
I know you can only have that in one place (green screw bonded to ground) and I am going through the wiring making sure I only have it grounded in one place. I came back to re-read what everyone has said and then I read your comment. I have read it many times, but I must not have understood it (which could be dangerous) IF I AM TOTALLY OFF-GRID, AND THE ONLY OTHER WAY TO GET POWER TO THE BREAKER PANEL TO POWER THE LOADS IS A GENERATOR, then what do I do about the green screw being tightened in this area of the fusebox? Does it still need to be tightened or will that cause a problem because of what you said with the Schneider already having it because there is no power coming in from AC1?
In the photo, I will be moving this main Neutral wire over to the main Neutral lug as suggested earlier. But the green screw (circled next to it) is tightened there in the main panel. If the Schneider already does this, then this screw needs to be removed right? I just need to be perfectly clear with your answer above.
IF I REMOVE THAT SCREW, then what happens if I switch the transfer switch to generator only (bypassing the Schneider altogether) to run the loads if that screw is removed? I think I am beginning to see a problem with this set-up unless I am wrong.
@BentleyJ @400bird @hwy17

 

[dougbert]

if that is your main off grid panel, then yes you should have that green screw installed. that is the single N-G bondnv
inverter should be configured without the N-G bond, ie floating neutral relying on the main off grid panel's bond

schneider does NOT have a N-G bond in itself. It relies on an external N-G bond

switching to generator as a source, then the generator should NOT have its neutral connected to the frame. Rather it should be a floating neutral in the generator and the generator will utilize the green screen N-G bond in your main panel

 

[hwy17]

I came back to re-read what everyone has said and then I read your comment. I have read it many times, but I must not have understood it (which could be dangerous) IF I AM TOTALLY OFF-GRID, AND THE ONLY OTHER WAY TO GET POWER TO THE BREAKER PANEL TO POWER THE LOADS IS A GENERATOR, then what do I do about the green screw being tightened in this area of the fusebox? Does it still need to be tightened or will that cause a problem because of what you said with the Schneider already having it because there is no power coming in from AC1?
In the photo, I will be moving this main Neutral wire over to the main Neutral lug as suggested earlier. But the green screw (circled next to it) is tightened there in the main panel. If the Schneider already does this, then this screw needs to be removed right? I just need to be perfectly clear with your answer above.

I didn't want to be rude to Bentley with a forceful correction, but I am personally certain for myself that the XW has no GN bond and never does.

So screw stays in panel all the time. XW is unbonded, generator is unbonded, both sources obey the green screw.

Only if you had a bonded generator that you could not unbond and needed to use would there need to be any rule breaking.

 

[SniperX]

if that is your main off grid panel, then yes you should have that green screw installed. that is the single N-G bondnv
inverter should be configured without the N-G bond, ie floating neutral relying on the main off grid panel's bond

schneider does NOT have a N-G bond in itself. It relies on an external N-G bond

switching to generator as a source, then the generator should NOT have its neutral connected to the frame. Rather it should be a floating neutral in the generator and the generator will utilize the green screen N-G bond in your main panel

@dougbert How do I configure without the N-G bond? I have the Neutral wire from its busbar going to AC out. Is that correct? The white wire is connected to the AC Load out and then down the neutral busbar (where it was installed from the factory) Is this what you are saying? The wiring diagram shows the path in pink. The middle area between the black (Line 1) and Red (Line 2) is the N. The bottom portion of the neutral busbar was prewired at the factory.

 

[SniperX]

I didn't want to be rude to Bentley with a forceful correction, but I am personally certain for myself that the XW has no GN bond and never does.

So screw stays in panel all the time. XW is unbonded, generator is unbonded, both sources obey the green screw.

Only if you had a bonded generator that you could not unbond and needed to use would there need to be any rule breaking.

Thanks. One thing I learned from Bentley's post, is if his scenario is correct, then I was able to see a problem with taking a screw out (where in the case of the generator- then there would be NO N-G bond) but if there was a N-G bond in the Schneider when off-grid/no AC in (grid in) then I would have had 2 NG bonds and that is a no-no too. At least, I learned to see there would be an issue, so not all was lost!

 

[hwy17]

At least, I learned to see there would be an issue

 

[dougbert]

@dougbert How do I configure without the N-G bond? I have the Neutral wire from its busbar going to AC out. Is that correct? The white wire is connected to the AC Load out and then down the neutral busbar (where it was installed from the factory) Is this what you are saying?

yes, your 2 pictures of wiring look good

I have the full PDP and my pictures are crowded - lots more wiring in it - so they won't help
you system is fairly simple since no grid

The wiring diagram shows the path in pink. The middle area between the black (Line 1) and Red (Line 2) is the N. The bottom portion of the neutral busbar was prewired at the factory.

let me echo your configuration so I am on the same page

1) transfer switch that toggles your main load panel between generator and the XW. Only one will be powering the loads

2) Transfer switch ONLY switches L1 and L2. Neutral is COMMON throughout the system

3) Ground is COMMON through out the system

4) N-G bond is only in the main panel. No bond in generator

Wire neutral from the XW through the PDP to transfer switch AND neutral from main panel to transfer switch. same with neutral from generator inlet plug to transfer switch

Ground do the same way, generator inlet, main panel and XW grounds all are connected to transfer switch

Generator L1 and L2 to one of the LINE sides of the transfer switch (top or bottom)
XW L1 and L2 to the other LINE side of the transfer switch

there are other topologies (wiring patterns) that will accomplish the same thing

if there are other features not mentioned, that could alter the design

 

[SniperX]

yes, your 2 pictures of wiring look good

I have the full PDP and my pictures are crowded - lots more wiring in it - so they won't help
you system is fairly simple since no grid




let me echo your configuration so I am on the same page

1) transfer switch that toggles your main load panel between generator and the XW. Only one will be powering the loads

2) Transfer switch ONLY switches L1 and L2. Neutral is COMMON throughout the system

3) Ground is COMMON through out the system

4) N-G bond is only in the main panel. No bond in generator

Wire neutral from the XW through the PDP to transfer switch AND neutral from main panel to transfer switch. same with neutral from generator inlet plug to transfer switch

Ground do the same way, generator inlet, main panel and XW grounds all are connected to transfer switch

Generator L1 and L2 to one of the LINE sides of the transfer switch (top or bottom)
XW L1 and L2 to the other LINE side of the transfer switch

there are other topologies (wiring patterns) that will accomplish the same thing

if there are other features not mentioned, that could alter the design

I believe that is what I have done. I labeled everything in the photos. The reason the Generator ground and Inverter Ground are in a double ferrule and then connected to the grounding lug is I do not have a 3 hole grounding lug. I put them in a double ferrule and then put into the one side of the grounding lug. I am searching for a 3 hole grounding lug so that it all fits nicely.

I still have to attach the battery bank and eventually my solar to this.

Will this be a problem not having any AC inputs (generator or grid) if I use batteries and solar?

I was going to attach the batteries if everything checks out ok so that I can update the insight home and commission the inverter.

 

[dougbert]

looks good to me for your system

 

[SniperX]

looks good to me for your system

Thanks for the help!!!

 

[wheisenburg]

I believe the Schneider has a dynamic N-G bond via a relay that closes when power is lost on AC1, which is always true in your off-grid situation.

On the Schneider ALL the neutral lugs are internally tied together. Generally you would have a "First means of disconnect" upstream of the Schneider. In this case where you are feeding a panel from the Schneider the ground neutral bond should really be upstream from the Schneider not in the panel that it is feeding. It the transfer switch is becoming the first means of disconnect and that is where the ground neutral bond should be located. The wire going to the actual building ground should be relocated to the transfer switch. The "Bonding" screw should then be removed in the panel that the Schneider is feeding. That panel has become a sub panel. It does appear that the ground and neutral wires in the panel have been kept separate, so there should be little work to do in that panel.

One important item to be aware of when running a wire from the ground in the transfer switch to the grounding rod it that this must either be a continuous unbroken bare copper wire or it must be spliced in a way that is permeant and irreversible such as a crimp. A wire where you could loosen and change the connection is not acceptable. I don't have perfect knowledge of the code, but you should check out the requirements on these "Building Grounding Conductors".

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[wheisenburg]

400bird is correct in that it doesn't matter if the legs get reversed somewhere

Mostly this is true so long as you do not have a current measuring device on the wires like a CT. In that case mixing up the polarity will cause the device to measure incorrectly. For example on the Enphase combiner box getting the polarity of the wires correct is very important. Multiple wires are fed through the same CT. If all the wires are not correct, they might be subtracted rather than added together which is what you want. An air conditioner won't care if L1 and L2 are reversed.

 

[wheisenburg]

@GXMnow or @400bird -do you have a second to take a look? Much appreciated.

This is nit picky and you will find many panels where this is not done, but when using a 12-2 Romex cable for a 240 volt only circuit (no neutral needed), you really should "Redesignate" the white wires using red electrical tape. This makes clear in the panel (and even more important on the receiving side of the cable) that the white wire is being used as a hot wire and is not a neutral. Now most experienced people looking at a white wire on an air conditioner are going to understand that this is a hot wire. A casual DIY home owner may assume that the white wire is a neutral. It takes only a few seconds, and it could save a life.

 

[400bird]

This is nit picky and you will find many panels where this is not done, but when using a 12-2 Romex cable for a 240 volt only circuit (no neutral needed), you really should "Redesignate" the white wires using red electrical tape. This makes clear in the panel (and even more important on the receiving side of the cable) that the white wire is being used as a hot wire and is not a neutral. Now most experienced people looking at a white wire on an air conditioner are going to understand that this is a hot wire. A casual DIY home owner may assume that the white wire is a neutral. It takes only a few seconds, and it could save a life.

Good catch. I don't know think you're supposed to redesignate wires that small. The minimum gauge is probably in the 8-10 awg region.