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Problem with inverter? High and low voltage error messages
I have a 24v off-grid system, with panels providing 900 watts (two 450w panels connected in series) and two 12v 150AH gel batteries in series.
The inverter is a 3KW 24v MPPT 50A/100V VPM hybrid from WCC Solar in Spain.
At night (eg 4am when dark) the inverter was beeping with an error message: [03]'battery voltage is too high'.
The first time the error message appeared the battery voltage was around or just over 30v.
The inverter wouldn't switch off using the on/off switch; I used the breaker switch on the cable
between the inverter and batteries to shut it down (and also the breaker switch between the panels and inverter).
In the morning after reconnecting/flipping up the breaker switch the error message only stopped after turning on an appliance (I used a 1500w hotplate).
Thereafter during the day I would leave the panels and batteries connected to the inverter. The error message wouldn't appear during the day
(with the exception of sometimes first thing in the morning immediately after restarting the system) even when not using much power, e.g. only charging a phone.
I started switching the system off at night (I was then able to turn the inverter on and off using it's own switch).
The error message appeared twice during the next week immediately when restarting the system in the morning. The battery voltage was 29.1v and the error message stopped when
turning on the hotplate. Later that morning the battery voltage was still 29.1v, around 4pm in the afternoon it was around 27.6v.
(I've also seen the battery voltage higher when restarting the system first thing in the morning).
I then checked the settings on the inverter in case it needed to be reconfigured; a few parameters were changed (eg relating to restarting the system automatically after a fault)
but not ones I'm aware of which would have caused the issue. As the problem was intermittent I wasn't sure if it had just righted itself or if adjusting a few settings had made a difference.
Thereafter it seemed fine for a few weeks.
About two weeks ago the inverter started beeping again at the night (not every night), now showing an error message that the battery voltage is too low.
The voltage reading might be 21.4v, for example. When this happens I turn off the inverter using the breaker switch between the inverter and batteries
(and between the panels and inverter). In the morning after restarting the system/flipping up the switch between the inverter and batteries (before reconnecting the breaker between the panels and the inverter) the inverter has not been beeping though. The voltage shows for example as 25.4v when restarting the inverter, dropping to around 24.6v after a few minutes.
I'm confused about
a) why the initial 'battery voltage too high' issue was only happening at night ( or first thing in the morning)
b) why the low voltage error message happening now intermittently comes on during the night but not first thing in the morning after reconnecting the inverter and batteries and before reconnecting the panels to the inverter.
c) I'm not sure if there's a problem with the inverter or if the batteries might now have been damaged.
The system was moved and reconnected by an electrician about two weeks before the problem first started.
Any thoughts would be appreciated.
The inverter is a 3KW 24v MPPT 50A/100V VPM hybrid from WCC Solar in Spain.
At night (eg 4am when dark) the inverter was beeping with an error message: [03]'battery voltage is too high'.
The first time the error message appeared the battery voltage was around or just over 30v.
The inverter wouldn't switch off using the on/off switch; I used the breaker switch on the cable
between the inverter and batteries to shut it down (and also the breaker switch between the panels and inverter).
In the morning after reconnecting/flipping up the breaker switch the error message only stopped after turning on an appliance (I used a 1500w hotplate).
Thereafter during the day I would leave the panels and batteries connected to the inverter. The error message wouldn't appear during the day
(with the exception of sometimes first thing in the morning immediately after restarting the system) even when not using much power, e.g. only charging a phone.
I started switching the system off at night (I was then able to turn the inverter on and off using it's own switch).
The error message appeared twice during the next week immediately when restarting the system in the morning. The battery voltage was 29.1v and the error message stopped when
turning on the hotplate. Later that morning the battery voltage was still 29.1v, around 4pm in the afternoon it was around 27.6v.
(I've also seen the battery voltage higher when restarting the system first thing in the morning).
I then checked the settings on the inverter in case it needed to be reconfigured; a few parameters were changed (eg relating to restarting the system automatically after a fault)
but not ones I'm aware of which would have caused the issue. As the problem was intermittent I wasn't sure if it had just righted itself or if adjusting a few settings had made a difference.
Thereafter it seemed fine for a few weeks.
About two weeks ago the inverter started beeping again at the night (not every night), now showing an error message that the battery voltage is too low.
The voltage reading might be 21.4v, for example. When this happens I turn off the inverter using the breaker switch between the inverter and batteries
(and between the panels and inverter). In the morning after restarting the system/flipping up the switch between the inverter and batteries (before reconnecting the breaker between the panels and the inverter) the inverter has not been beeping though. The voltage shows for example as 25.4v when restarting the inverter, dropping to around 24.6v after a few minutes.
I'm confused about
a) why the initial 'battery voltage too high' issue was only happening at night ( or first thing in the morning)
b) why the low voltage error message happening now intermittently comes on during the night but not first thing in the morning after reconnecting the inverter and batteries and before reconnecting the panels to the inverter.
c) I'm not sure if there's a problem with the inverter or if the batteries might now have been damaged.
The system was moved and reconnected by an electrician about two weeks before the problem first started.
Any thoughts would be appreciated.