question

slapperia avatar image
slapperia asked

Activate passthru relay when no power on input

Hi.
is there a way of activating the passthru output on the Multiplus-II when there is no input power on the inverter?

On the passthru output a hot water heater is connected. Sometimes I want to have this on even if there is no power coming in to the inverter. Is this possible? If not, is it possible to connect the inverter output to the passthru output with a relay?

System has a Cerbo and the MP-II 3000/120A

Multiplus-II
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Do you mean AC OUT 2 ?
If yes you can change that behavior with VE.config and the "programmable relay" assistant.

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slapperia avatar image
slapperia answered ·

Yes. Thank you. I will look into that.

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Kevin Windrem avatar image
Kevin Windrem answered ·

There is no pass-through path inside the Multi. The AC side of the transformer within the Multi is connected directly to the main AC output (AC 1) and for safety reasons, the AC input relay must be open when the unit is turned off. This relay will be open when the unit is off or the AC input is rejected for whatever reason. The AC 2 output is connected to the internal transformer also, so it can't supply power when the unit is off either.

If you want to bypass the Multi when it is turned off, you will need to add a changeover switch that routes incoming AC power to your loads.

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