question

charlietuna avatar image

Simple mechanical on-off remote switch for MultiPlus 24/3000/120 ac

I would like to be able to turn on and off remotely,the inverter, and separately the charger by a simple on-off spst switch for each feature. I have a stand alone Multiplus. I read on the forum it is "simple" but no details. Please assist.

Thanks,

Steve

MultiPlus Quattro Inverter Chargerswitch
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3 Answers
Mark avatar image
Mark answered ·

Yes, you can easily connect a simple single pole 3 position switch to remotely turn the unit ON / OFF / CHARGER ONLY (same functionality as the main switch).

This is only possible if you do NOT have a Digital Multi Control or a CCGX connected & the main switch must be left ON.

Refer to the instruction manual for the details - remove the jumper link and connect the external switch wires to the 3 pole terminal block inside the unit - labeled H in the manual.

If you want to achieve this with 2 independent ON / OFF switches (1 for inverter & 1 for charger) or be able to independently turn off the charger but leave the inverter on - there is no easy way to achieve this, but you could look into the use of an 'assistant'.

Extracts from manual attached below;


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This doesn't work on Multiplus MkIII 12/3000/120 software version 485:


Shorting left to mid delivers ON.

Shorting mid to right delivers CHARGE ONLY

But leaving all open causes the device to reset every 10 seconds, reboot, enter charge mode, and then after a few seconds reset again. Not what you want if you want to turn it off.

Charlie Johnson avatar image
Charlie Johnson answered ·

This functionality is included in the Victron Digital Multi Control: https://www.victronenergy.com/panel-systems-remote-monitoring/digital-multi-control-panel-gx

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Charlie,

Thank you for your prompt response. I'm aware of the Digital Multicontron, but I was wondering if a simple switch could be wired to temp sense to turn on or off the inverter?

Thanks,

Steve

kai avatar image
kai answered ·

Look at the two-signal BMS support assistant. You can configure the unit to read the temp sense and aux inputs to turn on/off the inverter and charger independently.


edit: pls ensure that your application can work with a profile that's consistent with the two-signal BMS assistant.

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Hi @kai,

Please be careful with your advice - as when the two-signal BMS support is activated, the Multi turns into a slave and all the charge settings are ignored.

Accordingly if there is no real BMS to continuously control the charge cycle, this will likely lead to overcharging & killing the batteries.

Do you happen to know a way around this? If not i suggest revising you advice/answer.

Refer to related manual;

https://www.victronenergy.com/upload/documents/Manual-Connecting-other-lithium-battery-systems-to-Multis-and-Quattros-EN.pdf

The text in the two-signal BMS support dialog needs to be interpreted quite literally I think. The text "VeConfig setting will be ignored" as I understand it is applicable only to force the charge curve to fixed. It does not remove the absorption or float set points.

I tested this just today - I artificially lowered the set points below the battery voltage and the multiplus stopped charging, while the BMS assistant remained active.

Happy to be advised otherwise.

Hi Kai,

Firstly I have not tested the logic of this assistant (yet...) & am going by the text.

To confirm do you mean that you lowered the Absorption voltage setpoint while the 2 wire BMS assistant was active and voltage was controlled/limited?

In that case it may only force the Multiplus into 'fixed' absorption time logic rather than using the time set as a maximum time with the 'adaptive' absorption time logic option (which is typically used for all lead acid based batteries).

This is a still a concern because absorption time is generally set to 6 or 8 hours but this duration is only required for a full/deep discharge, but in 'fixed' absorption time mode the battery will receive that duration of absorption charge even if it is only lightly discharged.

PS. The 'charge current control' assistant can also totally disable the charger, but due to the assistant setup it can only interpret Aux In as open=charger on, closed=charger off.

re: absorption setpoint, yes I did and VEConfig reported the voltage as requested. to be fair, I didn't pull out the multimeter or clamp meter to verify in wiring. I might do that next time I'm out there.

I have a LiFePo pack so I'm actually doing my best to configure out the absorption feature. In the more general case, yes some additional thinking / clarification from the assistant author(s) might be helpful.