Putting a transfer switch AFTER a Multiplus?

Question

question

overtaxed asked May 23, '23

Putting a transfer switch AFTER a Multiplus?

Is there any problem putting a transfer switch after the MPII (IE, connecting from the "out" side of the 120V system to a transfer switch)? My application here is that I'd like to connect a generator with autostart downstream of the MPII so that if there's an issue with the MP, I can monitor the power and autostart the generator to take over. That covers shore power loss as well as a problem in the inverter itself that prevents power from passing.

Shore power ---- MPII --- Transfer switch ---- Coach

Generator ----------------------^

I'm aware that would prevent my generator from being able to charge the batteries via the MPII, that's not a requirement for my installation (in fact, it's kind of benefit). Just wondering if this is a support topology and/or if anyone has wired this way.

Multiplus-II transfer switch

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2023-05-23T15:34:01Z

mvas answered · May 23, 2023 at 03:34 PM

Just verify that the Neutral-Ground bond is correct for both positions of the Transfer Switch.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 2 · 2023-05-23T21:34:58Z

Kevin Windrem answered · May 23, 2023 at 09:34 PM

Suggestion: put the generator/shore power transfer switch before the Multi. Then add a manual transfer switch in the position you show above to cover a failure in the Multi, or so you can shut it down for maintenance without disrupting the loads.

Look at my ExtTransferSwitch add-on that will switch the Multi from grid to shore and change the AC input current limit based on the transfer switch position.

https://github.com/kwindrem/ExtTransferSwitch

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 3 · 2023-05-23T23:49:13Z

Wayne answered · May 23, 2023 at 11:49 PM

I have used an Atkinson Electronics GSCM module ($240) in conjunction with a GX Cerbo and MP ll

This gives me the ability to programe in the Cerbo under what load conditions the genset should start, mine is behind the MPll so i dont lose the ability to charge as required as well.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question