The SunSaver MPPT and TriStar MPPT have several unidentified / numbered Alarm states. Numbered alarm information is as follows:
Alarm 19 = Power On Reset (the controller has recently been reset/rebooted)
Alarm 20 = LVD Condition (an LVD – Low Voltage Disconnect – event has occurred) Alarm 21 = Log Timeout Alarm (the controller’s internal logger has not been able to write a log entry for the past 24hrs)