SMA Sunny Island 220VAC/50Hz max current

rabbit_39
rabbit_39 Solar Expert Posts: 43 ✭
in Grid Tie and Grid Interactive Systems #1
Hello all,

I'm a little confused about this parameter on the Sunny Island 5048 parameter (for 230VAC/50Hz system): GridCurNom (Nominal power line current). The max value is 56A and it tracks well with the SI spec of 11,500Watt maximum power.

I assume this is the maximum power that the grid can give from the AC2 input, through SI5048 internal switch and then out to AC1. But it seems that every time I get near 5000W load the circuit breaker on the SI trips even though the grid is connected and supplying power. Is there another parameter I'm missing?

Thanks!
· Share on Twitter

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,654 admin
    #2
    Re: SMA Sunny Island 220VAC/50Hz max current

    What is the current rating of the breaker that is tripping?

    Also, is the load "highly inductive" or "non-linear"... I.e., running big old motors and some times of power supplies/battery chargers can use almost 2x the "expected current" because of poor power factor.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • rabbit_39
    rabbit_39 Solar Expert Posts: 43 ✭
    #3
    Re: SMA Sunny Island 220VAC/50Hz max current
    BB. wrote: »
    What is the current rating of the breaker that is tripping?

    Also, is the load "highly inductive" or "non-linear"... I.e., running big old motors and some times of power supplies/battery chargers can use almost 2x the "expected current" because of poor power factor.

    -Bill

    It's the breaker built in to the 5048.

    The loads are not too highly inductive (the only motors in the system are inverter based air conditioning units and 1 fridge). Right now the way it's set up is grid coming in through AC2, and then the loads are on AC1. Total combined loads are over 40A when everything is turned on with the grid operational (over the 5000W rating). But when the grid is down, I've got an automatic transfer switch that switches from the normal household loads to the emergency loads only (less than 5000 watts/25 Amps). Am I thinking right that as long as the grid is on, the SI can pass through more than 5000W but when the grid is down the SI can only give 5000W?

    Thanks!
    · Share on Twitter
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #4
    Re: SMA Sunny Island 220VAC/50Hz max current

    The only physical circuit breaker on the SI is the DC breaker from the batteries. If it's tripping while connected to the grid, then my guess is that you're charging the batts with too much current. Check what your charging current is set too, and also the max battery charging current.
    · Share on Twitter
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #5
    Re: SMA Sunny Island 220VAC/50Hz max current
    rabbit_39 wrote: »
    Am I thinking right that as long as the grid is on, the SI can pass through more than 5000W but when the grid is down the SI can only give 5000W?

    Yes exactly, check the spec sheet, it's not exactly 5000W and you can draw more for short periods of time.
    · Share on Twitter
  • rabbit_39
    rabbit_39 Solar Expert Posts: 43 ✭
    #6
    Re: SMA Sunny Island 220VAC/50Hz max current
    stephendv wrote: »
    Yes exactly, check the spec sheet, it's not exactly 5000W and you can draw more for short periods of time.

    Yep it looks like 11,500 Watt AC Input (internal circuit between AC2 and AC1 I presume) and 6500W to 30 minutes for the power generated by the inverter itself.
    · Share on Twitter

Categories