Sunny Boy 5000US or 4000US?

I've got 30 Sharp 170's and both the Sunny Boy 4000 and 5000 inverters will run 3 strings of 10 but the 5000 is more money and takes a lot more amperage at the main panel (50 AMP breaker for the 5000 and 30 AMP breaker for the 4000). The total STC output of the panels is 5100 Watts but I know the inverter will never see that 5100 watts. The Sunny Boy 4000US has a 5000 watt maximum and like previously stated is designed for the same 3 strings of 10 panels.

Is there any reason NOT to use the 4000?

Comments

  • FL SUNFL SUN Solar Expert Posts: 94 ✭✭✭✭
    Re: Sunny Boy 5000US or 4000US?

    What is the extra cost in the upgrade in the inverter and BOS components?

    Are you using NE-170UI panels? They overdrive the SB 4000 with cold temperatures. Not by volts, but by watts, according to the SMA string sizing. Cold sunny days may limit potential harvest if that is your climate. Vmp in high ambient is fine though.

    The 5000 is really more suited to handle your 30 panel array for overall winter/summer operation, in my opinion.
  • mike95490mike95490 Solar Expert Posts: 9,513 ✭✭✭✭✭
    Re: Sunny Boy 5000US or 4000US?

    Cold winter day, at noon, good sun, and you are likely to hit that power. But that's only 10 days out of the year. All depends on the PV angle, how much power you will get.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • LHawesLHawes Solar Expert Posts: 46
    Re: Sunny Boy 5000US or 4000US?

    Yes, using the NE-170U1 panels and actually have (2) 30 panel arrays to deal with). Not the best angle, not the best exposure in a warm Tucson environment. They have the potential to produce 5100 watts and the 4000 is rated for 5000 max. but I can't imagine them ever getting there - in any climate - is that a safe assumption? I've never heard of panels ever reaching their STC rating in any real world conditions, but that's why I'm asking here.

    The kicker is the (2) 50 AMP breaker required for the 5000 which may require a sub panel off the main 200 AMP panel and #6 or 8 wire whereas the 4000 only needs a 30 AMP with #10.

    Sorry don't know what BOS stands for. The 5000 I can get for around $3300 and the 4000 for around $2500.

    Thanks for the help

    From the SMA web site:
    "Inverter Maximum DC Input Power (PDCmax):
    This is the recommended maximum DC input power that should be attached to the inverter. This number is in STC watts, which is usually the nominal output rating of the PV panels. This can be larger than the maximum rating of the inverter because STC watts are usually not the amount of power that the inverter is actually receiving. For a brief introduction to this concept please see this discussion of STC vs. PTC ratings for PV panels."
  • FL SUNFL SUN Solar Expert Posts: 94 ✭✭✭✭
    Re: Sunny Boy 5000US or 4000US?
    LHawes wrote: »
    Yes, using the NE-170U1 panels and actually have (2) 30 panel arrays to deal with). Not the best angle, not the best exposure in a warm Tucson environment. They have the potential to produce 5100 watts and the 4000 is rated for 5000 max. but I can't imagine them ever getting there - in any climate - is that a safe assumption? I've never heard of panels ever reaching their STC rating in any real world conditions, but that's why I'm asking here.

    The kicker is the (2) 50 AMP breaker required for the 5000 which may require a sub panel off the main 200 AMP panel and #6 or 8 wire whereas the 4000 only needs a 30 AMP with #10.

    Sorry don't know what BOS stands for. The 5000 I can get for around $3300 and the 4000 for around $2500.

    Looks like you've got your work cut out for you, and a productive set-up to boot. Sounds like you're set on the inverters and as mike90045 said, derating of power should be minimal with your climate.

    BOS - Balance of system components: The other items needed in the PV system other than inverter and the modules.
  • mike95490mike95490 Solar Expert Posts: 9,513 ✭✭✭✭✭
    Re: Sunny Boy 5000US or 4000US?

    What's the overload mode for the inverters - if you feed them too much power, will they self-limit to a safe condition, or merrily cook along till they die ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Solar GuppySolar Guppy Solar Expert Posts: 1,981 ✭✭✭
    Re: Sunny Boy 5000US or 4000US?

    All gridtie inverters that are UL listed will just sit at the power limit ... just wastes the available PV harvest, but no issues for the inverter
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