Combiner Box Breaker Tripping

cottager1869
cottager1869 Registered Users Posts: 5 ✭✭
One panel and breaker in our 6 panel combiner box continues to trip. We replaced the original 10 amp breaker with a new 15 amp one on the advise of our supplier.  The panel and the breaker were six years old and have worked fine for that time.  Any ideas for the cause and a simple fix.  We have 6 24 volt Sharp 175 watt panels with an mpp of 35.4 volts all with 10 amp breakers.  They have all worked well for 6 years with no problems.  There have been no recent changes to the system.

Comments

  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    Swap positions in the box with another panel and see if the tripping moves with the wire change. Observe the panel very closely for a visible defect.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • cottager1869
    cottager1869 Registered Users Posts: 5 ✭✭
    Tried that already with no luck.  It is definitely in that panel and its connections.  It seems to only trip at night.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    My guesses...

    A bad charge controller that is feeding voltage/current back to the array at night? Even then, a good array should not let very much current through (backwards) and I would never expect it to trip the breakers--Unless there is a shorted solar panel/array.

    Second--A bad terminal/connection somewhere. Water got in a corroded a terminal/wire end. The heat could trip/damage a breaker (look for overheated insulation on wire/breaker terminal area).

    Otherwise, get a DC current clamp meter and see if there is any current flow at night. Does not make sense. If the array and charge controller are working correctly, there should never be enough voltage/current to trip a breaker at night.

    http://www.sears.com/craftsman-digital-clamp-on-ammeter/p-03482369000P

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • cottager1869
    cottager1869 Registered Users Posts: 5 ✭✭
    Thanks. 
  • cottager1869
    cottager1869 Registered Users Posts: 5 ✭✭
    After taking the panel back to the manufacturer which took almost a year it turns out to be a manufacturing fault.  They replaced the panel no charge no shipping cost only the aggravation of being without that panels output for 2 years.  
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Thank you for letting us know... And sorry for your frustration getting it repaired.

    Any details on what failed?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • cottager1869
    cottager1869 Registered Users Posts: 5 ✭✭
    Some of the cells were not properly connected so no repair was possible.  They had never found that problem before.