nmeyrick avatar image
nmeyrick asked

Is there any way to switch between 2 inverters?

My system is on a sailboat with 230v 50Hz AC, 24v DC system and 675Ah of deep cycle batteries. I currently have an old 2kw inverter, and recently added a small 500w Phoenix VE Direct inverter to directly power sensitive loads like Starlink.

I'm in the process of upgrading the electrics by switching the 2kw inverter for a Multiplus 24/5000 (will be fitted by a qualified electrician, alongside any other AC changes needed), adding more solar (will be total of 1250w in three banks, fed to smart solar MPPTs) and a Cerbo GX to monitor it all.

My initial plan was to have the Multiplus set up in passthrough mode for incoming power from shore power or onboard generator, then providing inverter power to all AC sources when away from an external source.

I just spoke with another boat owner with a similar set up, and he mentioned that when away from the dock he keeps his multiplus 24/5000 switched off when not needed to run a large load due to the high power draw at idle which can be as much as 45w even with all ac sources switched off.

From this I'm wondering if there is any way to have the small Phoenix inverter running as default to cover small loads like small appliances, laptop charging etc, then be able to switch across to the multiplus when needed to run larger loads, with both feeding the same distribution panel?

I gather it is a problem to have both live at the same time, or is there a way this can be co-ordinated? If I need to ensure that only one inverter can be live at a time is there any way to control that via the Cerbo, as both will be connected to that?

Alternatively I can see that both inverters have a remote on / off switch option, I'm thinking that if there isn't a better option I could wire a three double pole three position switch to the remote switch input of both inverters, so that I can use it to switch Phoenix on, both off or Multiplus on. Is there any reason that should not work?

Thanks for any insights or suggestions


cerbo gxPhoenix Invertermultiple inverters
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2 Answers
snoobler avatar image
snoobler answered ·

Don't believe the MP burns 45W. My Quattros burn about 28W each. I suspect Mr. 45W has some unaccounted for DC loads.

Have you looked into the Multiplus-II options? They have notably lower idle burn.

You could have your inverter outputs hooked to an ATS. Whichever inverter is on will power the panel.

You can't have multiple inverters connected to a single GX unless they are identical models operating in parallel. You can connect a VE.Direct Phoenix to the GX in addition to your GX, but it can only be accessed through the GX console, and monitoring/control is very limited.

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iand avatar image iand commented ·
There have been multiple report of Quattros or Multiplus having higher zero-load power than specified -- and also multiple reports that they meet the spec.

IIRC there was a comment from Victron that the spec figure is typical but there's significant variation between units, some are considerably higher than spec and there's no cure for this...
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nmeyrick avatar image
nmeyrick answered ·

Great, thanks for that - I’ll wait and see what the idle consumption is like in reality. Size wise the Multiplus II is not a good fit for our install location so I’ll skip that for now. I don’t think I will pursue trying to run both inverters, other than possibly leaving the small one on for some specific loads on a separate circuit.

Good to know that the small inverter won’t be able to connect properly to the Cerbo, that’s not a deal breaker.

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Kevin Windrem avatar image Kevin Windrem commented ·
Specs say 11 watts for the 2000 VA Multi and 5 watts for the Phoenix.
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iand avatar image iand commented ·
The new Venus OS 3.10 allows solar priority when a boat is plugged into shoreline, so the Quattro/Multiplus can be in charger mode instead of inverter (lower power). If I understand this correctly AC loads are then powered by the shoreline, DC by the batteries which are kept topped up by solar.
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nmeyrick avatar image nmeyrick iand commented ·
Thanks I saw this was just released, definitely keen to try that out once we have our multi fitted.

Thanks all for the input

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