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Neil Pavia avatar image
Neil Pavia asked

Need Multiplus to ignore generator AC during cool down

I have an SDMO Silence 6kva generator.

When CCGX send a shut down signal (opens teh relay switch) the generator continues to Run for 60 seconds to cool down - I cannot change this - its programmed this way.

during this time, for whatever reason, the cool down period triggers an overspeed alarm on the generator - but ONLY because the Inverter is still drawing load from the generator.

When I manually flick the MCB off during the cool down period, the generator shuts down without error.

Is there any way I can instruct the Inverter to ignore AC input AC1 when the switch relay is open?

Generatorshutdowngen start
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4 Answers
CM avatar image
CM answered ·

gui mods, ext transfer switch , install that and it will hold the relay until the gen is done

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Kevin Windrem avatar image
Kevin Windrem answered ·

With v3.0 (I think that's the right version) or later, cool-down can be specified in the generator setup in the stock Victron code. During this time, the Multi is told to ignore the AC input. You need to have a recent version of the Multi code however. Not sure which version added that but the latest certainly does.

BTW, GuiMods and/or ExternalTransferSwitch won't help without the latest Multi firmware.

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Neil Pavia avatar image Neil Pavia commented ·
Yeah I updated the firmware to have cool down setting but it didn’t help because at cooldown, the relay ignores AC but keeps the relay switch closed… when after the cooldown period is over, the relay switch opens (to shut down the generator) but then the genset itself does its own cooldown and at this point the AC current it generates is picked up by the Multi and I get my problem.


What I need is a way to simply ignore AC unless the generator start stop relay is closed.

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Kevin Windrem avatar image Kevin Windrem Neil Pavia commented ·

There is actually a short delay at the end of the cool-down period before the ignore AC input is lifted by the GX device. That delay is hard-coded at 15 seconds: WAIT_FOR_ENGINE_STOP = 15 in startstop.py

You could edit the file and change it to say 70 seconds but you'd need to do that after each firmware update. An adjustable post-cooldown delay was considered but no one could think of a good reason to do so. Maybe that's what should be done.

@mvader (Victron Energy) is there interest in Victron adding this?

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Neil Pavia avatar image Neil Pavia Kevin Windrem commented ·
Is this something I could edit myself?
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Kevin Windrem avatar image Kevin Windrem Neil Pavia commented ·

Yes, it is one line near the beginning of the file.

/opt/victronenergy/dbus-generator-starter/startstop.py

After you edit the file, reboot or:

svc -t /service/dbus-generator-starter

to restart the generator service.

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Neil Pavia avatar image Neil Pavia Kevin Windrem commented ·
thanks so much for your help

unfortunately this goes beyond my skillset - I only have access via internet - not with the cable. Darn

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Neil Pavia avatar image Neil Pavia Neil Pavia commented ·

one final ray of hope - how can I get this file that i need to edit? are there instructions about the topic? can I be done through the laptop software Ve config? (without the cable)

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Kevin Windrem avatar image Kevin Windrem Neil Pavia commented ·

No, you would need to ssh in to the GX device or scp or ftp the file back and forth to another computer. These all require an ethernet or WiFi connection to the GX device then setting it up to accept the commands. That's discussed here:

https://www.victronenergy.com/live/ccgx:root_access

You do not need a dedicated keyboard connection to the GX device.

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Neil Pavia avatar image Neil Pavia Kevin Windrem commented ·

sorry for the silly question, but it says go to settings / general - I'm not sure where it means.

are experts available her to log in remotely (for payment of course) and do it or show me how to log on?

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Kevin Windrem avatar image Kevin Windrem Neil Pavia commented ·

The access that's being discussed is from the main GUI:

Menu brings up the Device List, then at the bottom (or top if you have GuiMods installed), you'll find Settings, then at the top of that menu is General.

If this is confusing to you then it may be best not to attempt changing files.

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Neil Pavia avatar image Neil Pavia Kevin Windrem commented ·
I've made it to putty - if I could please ask one last question.

when trying to log into putty I'm pasting the IP address I've found on the device list (Gateway) - I past the IP but nothing, also tried root@IP - still no joy.


any final pointers? unfortunately we don't have a servicing team for this stuff where I'm from

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Kevin Windrem avatar image Kevin Windrem Neil Pavia commented ·
You need to set up a root password on the GC device and enable ssh access or the connection will be rejected. That's covered in the document I linked to above.

Sorry, not at all familiar with putty as I'm on a Mac and have a native unix command line interface.

If you are on the same network, you can may also be able to use root@venus.local.

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Neil Pavia avatar image Neil Pavia Kevin Windrem commented ·
thanks. yes I did all the steps up to putty, but no matter what I put in the ip field, it wont logon - thanks so much for your help nonetheless.

If anyone here would like to offer paid service to use team viewer to do this Id be very happy to pay for the service.

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Kevin Windrem avatar image
Kevin Windrem answered ·

I had a few minutes and adde an adjustable post-cool-down delay. It's in GuiMods v8.17.

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mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Nice @Kevin Windrem and thanks for the report @Neil Pavia .


We’ll have another look at this for standars Venus OS as well. But that will be a while before we do.

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·
Ps, by the looks of it, having a setting for this + proper explanation in the manual, should be sufficient indeed
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CM avatar image CM mvader (Victron Energy) ♦♦ commented ·
yes please, we would appreciate ,i certainly would
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Related Resources

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MultiPlus Generator FAQ

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Automatic Generator start/stop

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Virtual switch - Generator start/stop

Additional resources still need to be added for this topic