Faulty Steca PR1515?

ollyomm
ollyomm Registered Users Posts: 10 ✭✭
Hi there, love your work here, very helpful
So I have a Steca PR1515, perhaps 20 years old, has never let us down until now, connected to two 75W panels and a 90W panel on a swivel mount, all 18V. 
While I was waiting for a new MPPT controller to arrive I had it connected to a new 260W 35V panel, I know its a big no no but it seemed to work fine at the time and we needed the boost as it was a grey winter and batteries were getting down. 
Now I have the MPPT controller and that is working fine on a completely separate system and I have reconnected the old 18V panels to the Steca but it will not stop rising in volts, the highest I allowed it to get was 15.5 V before I disconnected

I assume I have cooked it but its frustrating as it was working fine with the 35V panels, stopping at 14.4V
Any advice aside from buy a new one?
Thanks in advance

Comments

  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,037 ✭✭✭✭✭
    Try disconnecting the PV then the battery. Connect the battery and then the PV. It may just need to reboot and select the battery voltage again.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    +1 on making sure to connect battery first. It appears to be a 12/24v pwm controller, and may think 24v based on pv input. It supposedly has protection for high pv input (current specs), so connecting the high voltage panel may not have let the magic smoke out.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • ollyomm
    ollyomm Registered Users Posts: 10 ✭✭
    No luck with resetting the voltage, still wants to keep climbing up past 15V, any other suggestions?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    10+ year old electronics, especially power electronics, are at the age where failures are more common. Usually nothing that can be field repaired. And 5+ year old electronics start to fall out of factory service (difficult to obtain spare parts).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Did it boot fully from the battery only, with the panels disconnected?  

    I don't know that controller, but is there a manual switch for voltage setting or equalization that might have been hit by mistake?

    Does it make any noise as the voltage gets up to 15ish volts?  Did it with the 35v panels when it got to 14.4v?  Some controllers make a noise, sort of a whine, as the switching on/off occurs to control voltage.  If the switching isn't happening because it's fried, there likely wouldn't be a noise when there was one before.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • ollyomm
    ollyomm Registered Users Posts: 10 ✭✭
    Yes I allowed it to boot fully from batteries before connecting panels, 

    No manual switch for voltage, only says ensure connected, battery, panel, load

    Dont recall any noises being made, apart from the Gel batteries whining about the high voltage. will give one more go today.

    PS Estragon, with a separate day and night system how do you switch between?
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I just switch a simple generator lockout panel so that only lights etc. are powered off the 12v system at night.  The panel looks like:
    https://www.homedepot.ca/en/home/p.60-amp-generator-panel-with-18-spaces-36-circuits-maximum.1000722301.html

    My guess is the controller isn't switching on/off to control voltage.  No idea why it was apparently working okay while still connected to the 35v panel though.  You would think if it was fried by the voltage, it would have misbehaved before.  Maybe grey days and loads kept the voltage down?  Dunno.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter