Switch on MPPT battery side - will it damage the MPPT?

DIY
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Hi,
If I put a relay or switch to break the circuit on a Victron MPPT (for example 75/15), will the MPPT unit be damaged by doing so? Or is there any other concern with that?

Any theories around this?

Or even better: Practical positive or negative experiences of this.

I know that Victron recomends that the PV-side should be removed first, then the battery side. And the reverse order when connecting back.

A use case could be: 4 solar cells with their own MPPTs (=4) could be disconnected with one switch on the battery side ratehr than 4 switches on the PV side.. Just an example..

Thanks.

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I just turn my MPPT off in settings when I don’t want it charging.
If you switch the battery side off the MPPT could default to 24v when they are switched back on.

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This is considered standard practice. Works fine. Just follow the on/off procedure you wrote. All my PV installs use this design, though all my installs are on an RV or associated with an RV.

The disconnect between the PV and solar charge controller needs to break both positive and negative. This can be done with a dual pole circuit breaker or a PV disconnect switch. The theory is that the solar panels may be grounded to the chassis, on purpose or not. If only the negative cable is on a breaker (very unusual, as we usually put OCP on the positive leg) and that breaker is opened, there could still be PV voltage put into the trailer. By breaking both positive and negative legs, it’s all shut down and safe to handle.

I’m not an electrician. The above explanation was provided by someone that knows way more about electricity than I do.

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Thanks! Good suggestion to use the “SW-turn off”:

But I also have a case where my BMS will shut down the charging using a relay on the battery side..

Question: Do you have experience that the MPPT goes into 24 V mode when connected back (to a 12V sytem)?

AND: I can set the system voltage to 12V, I think, so it would prevent any erranious voltage setting(?)

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It only happens on an MPPT controller when there is an auto sensing setting for battery voltage as it can’t sense the battery voltage so defaults to the one nearest the PV voltage.

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