Reverse PV polarity
As long as the Multi RS19 Solar is installed within the published specifications, the PV inputs are protected internally against PV reverse polarity.
In the case of reverse PV voltage, the Multi RS19 Solar will not indicate an error.
The only way to detect reverse PV voltage is by the following signs:
The Multi RS19 Solar is not charging the batteries, the charge current is zero.
The Multi RS19 Solar is getting hot.
The PV voltage is zero, or close to zero.
If this is the case check for reverse polarity using a multimeter by ensuring that the positive PV cable is connected to the positive PV terminal, and the negative cable is connected to the negative terminal.
Caution
Measuring PV voltage at the PV terminals of a solar charger should only be performed by a professionally trained solar electrician.