The Phoenix 1200 has two setting to prevent total discharge of the battery by the inverter. One is restart/alarm and the other is a low voltage shutoff. The factory sets the restart/alarm voltage to be higher than the low voltage shutoff. I believe the intention is to have an alarm when the voltage goes below the restart/alarm set point and to have the inverter shut down when the low voltage shutdown setpoint is passed. However, on my Inverter when the voltage drops below the restart/alarm setpoint the inverter shuts down and restarts when the voltage goes above the set point.
I don’t think this is correct functioning. First, when a battery is suddenly unloaded it’s voltage will rise. In this case it would cause the inverter to continuously shut down and restart. Second, if the inverter shuts down at the restart/alarm set point why have the low voltage shut down at all?
What are the settings and what are you using to measure voltage to diagnose this. It is possible that the voltage drops so quickly on high loads that it goes from alarm to shutdown with little time between and voltage recording misses the minimum voltage. This would be the case with too small a battery bank or batteries in poor condition or a high voltage drop in the DC cabling.
Not diagnosing anything. My question is about how restart/alarm set point works and how the low voltage shutdown set point works. It has nothing to do with what is actually happening now.
And FYI the batteries are new and well sized sodium silicate gel cells. The biggest load is 19watts. And the cabling is the recommended size which is 6AWG for this application.
Since this is a remote system I must depend on the inverter and BMS to tell me the battery and inverter voltage. They are in good agreement with the inverter being .01 volt below the battery at the shunt. This is expected.
And finally, there is a 1 volt difference between the alarm and low voltage shutdown set point. No danger of the load dropping the voltage that much.