question

Hope you can help with this question.

An easysolar-II 48/3000 GX, installed 12 wks ago (approx) ran well for 6 weeks then the MPPT went into OFF mode and couldn’t easily be rectified. After about 2 hours, we got it working with the steps below. Then it has happened again after some loads were left on overnight and the battery SoC dropped. Summary of below: if the CAP on the mppt interface board is discharged, then the MPPT will come out of the OFF mode. Sounds similar to the other community question link below. (the Installer thinks that installing a large resistor across two points on the mppt interface board will overcome this infrequent problem) This may be tried if we cant get a response.

https://community.victronenergy.com/questions/47095/easysolar-ii-gx-not-charging.html

STEPS (sorry - the numbering went funky when cut and pasted from email)

1. SYSTEM – Easysolar-II 48/3000-GX, 2 x Powerplus ECO4840P batteries, One sting of 6, CS3K300P - 300W panels.

• Voltage readings - PV DC isolator on.

1. 
   
   • Input to Interconnect board - 230V
   • Output of Interconnect Board - 230V
   • Input of MPPT - 10mV

• Voltage Readings PV DC Isolator Off
  • Input to Interconnect board - 220V
  • Output of Interconnect Board - 220V
  • Input of MPPT - 10mV
  • Capacitor on Interconnect board not discharging
  • Assume had a faulty interconnect cable between Interconnect board and MPPT

11. Disconnect Interconnect cable from MPPT and check continuity and Voltage

• Voltage Readings PV DC Isolator Off
  • Input to Interconnect board - 220V
  • Output of Interconnect Board - 220V
  • End of output cable - 220V
  • Capacitor on Interconnect board not discharging
• Voltage readings - PV DC isolator on.

1. Repeat
   
   • Input to Interconnect board - 230V
   • Output of Interconnect Board - 230V
   • End of output cable - 230V
   • Capacitor on Interconnect board not discharging
   • Cables OK

12. Reconnect Cables to MPPT PV - DC isolator Off

• Capacitor on Interconnect board now discharging
• Voltage dropping as read with meter.

13. Turn On PV DC Isolator

• MPPT now working.

See attached download of history data.