Skybox battery inrush current

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mytaytay
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Skybox battery inrush current

Post by mytaytay »

What is the inrush current for the battery circuit when I turn on the battery breaker in the BOS ? I have a 48V, 16s 280aH battery pack with a 150 amp class T fuse between the battery pack and the skybox. When I turned on the battery breaker in the Skybox BOS it blew the 150 A fuse. The fuse is a Littlefuse JLLN 150A-P which is fast acting. So far I can't find a slow-blow class T fuse. Does Outback have a recommended fuse/circuit breaker that can handle the inrush of the skybox ?

Thanks
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Mike Curran
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My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, battery backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Skybox battery inrush current

Post by Mike Curran »

I don't know but I can't believe it's over 150A. Before you turn on the breaker, is the red led indicator on the breaker lit? If so your battery polarity is reversed. If not I would recommend rechecking all of your wiring. And make sure that when you're switching the battery breaker on that your AC load breaker is open (off).
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-04-19
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
mytaytay
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Re: Skybox battery inrush current

Post by mytaytay »

No, the red light on the breaker was not on. I verified correct polarity and wiring is correct. I did have the AC breaker on. I will try powering up the skybox with battery only (line AC & load AC breakers off). Just waiting for my replacement fuses now. Thanks
Electrictrauma
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My RE system: Skybox 24 260 watt panels, 2 12 string kong 48 volt 233 amp lipo4 battery 12k watts

Re: Skybox battery inrush current

Post by Electrictrauma »

I have roughly the same size battery but a 300 amp fuse. However mine has generally tripped when conditions were set outside bms parameters so check skybox settings against your bms and monitor your bms.
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