How to operate an RMxxxx with a solar panel?

The RM(X)8XXX has the facility to accept a S+ signal to the control PCB allowing it to select solar DC power when available. To use this function, it is necessary to use a “Büttner by Dometic” solar regulator with a signal output cable which can be connected to the S+, the solar power then charges a battery or battery bank and when the regulator sends the signal to say voltage is available the fridge will select this first in AES mode. Some details on solar regulators can be found here.

In automatic mode, the refrigerator selects the most favourable operating mode available

Priority	Operating Mode
1 Solar	(DC power)
2	AC power
3	DC power
4	Gas

Most AES installations are wired with the 12V feed coming from the vehicle battery the alternator supplies a D+ signal allowing the fridge to draw DC power. When wiring the fridge to use a S+ signal you will require a changeover switch to change the 12v heating element supply from vehicle batteries to leisure batteries. The RM(X)8XXX uses between 120W & 190W heating elements on 12V as a heat source, therefore when operating on DC the product will draw between 10A & 15A continuously. Most vehicles are not set up with enough leisure battery power to be able to run the fridge for long periods via solar/dc, this function is often used when the product is installed in beach huts or other off grid locations, please be aware that altering the vehicle wiring may invalidate your warranty, we would recommend you check with your responsible dealer before proceeding.