N-G bond with Victron Autotransformer

[AZ Solar Junkie]

I'm pondering possibly getting a Victron autotransformer to balance the loads on the 2 legs from my 6000XP. If the legs were close to perfectly balanced, I would be able to run my electric dryer without needing to get a second 6000XP, as when the dryer runs one of the 2 legs is just enough over the inverter capacity to cause it to switch to bypass. What I'm not sure about is how to handle the N-G bond in such a scenario, since the autotransformer would be creating a new neutral. Is it as simple as having the neutral from the autotransformer connected to neutral in the loads panel, and also having the neutral (and ground) from the main panel where they are bonded, also connected to the neutral and ground bus bars in the loads panel? This means the neutral to the loads is effectively connected to both the autotransformer and to the main panel - not sure if that creates some sort of issue...

 

[timselectric]

Because you have a grid pass through option. The neutral from your main panel needs to connect to the autotransformer neutral and the sub panel neutral bar.
I believe that the victron autotransformer has provisions for N/G bonding. If so, this must be defeated so that it's never engaged. And for the autotransformer to do what you want. You have to remove the neutral connection from the 6000XP.
Ground connects to everything as usual.
Make sure that the autotransformer is capable of handling the inverter or pass through full amps. Whichever is the largest.

Note: when in pass through, the autotransformer is in parallel with the grid transformer. Sometimes, this can be a problem.
There may be other special wiring considerations. The victron autotransformer is not a standard autotransformer.

 

[AZ Solar Junkie]

Because you have a grid pass through option. The neutral from your main panel needs to connect to the autotransformer neutral and the sub panel neutral bar.
I believe that the victron autotransformer has provisions for N/G bonding. If so, this must be defeated so that it's never engaged. And for the autotransformer to do what you want. You have to remove the neutral connection from the 6000XP.
Ground connects to everything as usual.
Make sure that the autotransformer is capable of handling the inverter or pass through full amps. Whichever is the largest.

Note: when in pass through, the autotransformer is in parallel with the grid transformer. Sometimes, this can be a problem.
There may be other special wiring considerations. The victron autotransformer is not a standard autotransformer.

Thanks Tim - yeah the more I look at this the more I'm feeling it will unnecessarily complicate things - especially with a non-Victron inverter (because the Victron inverters have a connection specifically to control the N-G bond in the autotransformer). I'm probably better off to just add a second 6000XP I think, which will have its own benefits except adding more internal consumption from the second 6000XP. I'm not sure how much that will compare to the power consumed by the Victron autotransformer.

 

[timselectric]

Thanks Tim - yeah the more I look at this the more I'm feeling it will unnecessarily complicate things - especially with a non-Victron inverter (because the Victron inverters have a connection specifically to control the N-G bond in the autotransformer). I'm probably better off to just add a second 6000XP I think, which will have its own benefits except adding more internal consumption from the second 6000XP. I'm not sure how much that will compare to the power consumed by the Victron autotransformer.

Maybe you can turn off the second one until you need to run the dryer.

 

[AZ Solar Junkie]

Maybe you can turn off the second one until you need to run the dryer.

My thought exactly