Burnt wire and arc fault

Discussion about the FM100 AFCI Charge Controller
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santafedave
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Posts: 36
Joined: Sat Dec 05, 2020 8:05 pm
My RE system: GS8048-A-300AFCI 8 KW 48V Mate3s with 2 FM100 charge controllers pre wired.
21 Canadian Solar 320 Watt PERC MC4 CS3K-320MS panels.
3 Canadian Solar 325W Module Mono Perc 1000VDC panels.
8 FullRiver AGM DC400-6 Sealed Batteries 415AH 6V L16 size.
Fireraptor quick disconnect.

Burnt wire and arc fault

Post by santafedave »

Hello. One of my CC failed last week burning the wire and I had to ship it back to Outback for repair. My question is I have my other CC still hooked up, but, it is stuck in silent mode and will not accept power from my PV's. I called Unbound Solar and talked to my tech rep there. We checked both the fuse (600v .75 amp) and taking the jumper off of the cc to see if you would start charging. No luck. Does any have any experience with trying to get the CC up and running when one has been removed. I am in mini grid mode right now trying to save a little money from the utility because I am on a tiered schedule. Pics of my system are below.
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CC port 8 in silent mode.png
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Mike Curran
Forum Emperor
Posts: 2479
Joined: Sat Aug 28, 2004 6:28 pm
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: Burnt wire and arc fault

Post by Mike Curran »

The only thing your 2 CCs had in common is the battery. Removing one should not affect the other's operation. There must be something else going on, not related to the failed CC. Sorry I can't offer much more than that. Which wire "burned"?
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-04-19
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
santafedave
Forum Whiz
Posts: 36
Joined: Sat Dec 05, 2020 8:05 pm
My RE system: GS8048-A-300AFCI 8 KW 48V Mate3s with 2 FM100 charge controllers pre wired.
21 Canadian Solar 320 Watt PERC MC4 CS3K-320MS panels.
3 Canadian Solar 325W Module Mono Perc 1000VDC panels.
8 FullRiver AGM DC400-6 Sealed Batteries 415AH 6V L16 size.
Fireraptor quick disconnect.

Re: Burnt wire and arc fault

Post by santafedave »

The red PV wire. Burnt the contact point.
User avatar
Mike Curran
Forum Emperor
Posts: 2479
Joined: Sat Aug 28, 2004 6:28 pm
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: Burnt wire and arc fault

Post by Mike Curran »

Aren't those FM100s somehow daisy-chained for the ground fault circuit? Is that the jumper you're referring to?

Does the FM show that there's input voltage coming in from your PV? Maybe you have to look at your Mate to see that...

FWIW, a burnt wire at the contact point often indicates there was a loose connection there. Not sure how that would screw up your FM, but anything's possible, I guess.

Edit: Even if your Mate indicates 0 volts from PV, I'd double check with a meter if you can. Careful, high voltage!
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-04-19
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
fcwlp
Forum Czar
Posts: 877
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600W PV Fixed, FM80 w/2,700W on Zomeworks tracker, Mate3, 24 Trojan 2V L16 1100AH @ C20, Grid-Tied with Kohler 14RESA LPG Generator and MEP-803 Diesel if needed.

I install and maintain grid-tied and off-grid systems in my area and consult on solar system design/operation.
Location: 80 miles NE of Phoenix at 5500'

Re: Burnt wire and arc fault

Post by fcwlp »

Mike Curran wrote: Fri Jul 30, 2021 7:47 pm Aren't those FM100s somehow daisy-chained for the ground fault circuit? Is that the jumper you're referring to?
Mike is on correct path. If you sent the primary unit in, you have to reinstall the fuse in the current unit. Leave all jumpers in place.
pss
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Posts: 862
Joined: Mon Jul 24, 2017 8:40 am
My RE system: 8330 watts in three strings, Flexmax 60 x 3, Radian 8048A, GSLC load center, Mate 3S, Hub 10.3, FN-DC and 900 Amp, 48V Trojan T105-RE battery bank.

Re: Burnt wire and arc fault

Post by pss »

You are getting good advice. Very important to go out to array, check the voltage on each string of panels and make sure no DC breaker was tripped. Next, check the voltage from the array exiting the combiner box. If you have a clamp meter, measure amperage too (should be like zero if not charging). Next go to your DC disconnect switch. measure input and output voltage. Turn the DC disconnect switch ON and OFF. make certain it is functioning normally. Compare the voltage at the output of the DC disconnect switch (my switch has solar rated duses on each array, which is optional) to the input of the FM100. Should be the same (or very close). Then make certain all settings on the FM100 and any jumpers are correct for a single unit. Next measure voltage at output of FM100 to battery bank and at the input of battery bank. Between those 2 points, there should be a DC breaker or a fuse and DC ON/OFF switch. AT EVERY POINT ALONG YOUR VOLTAGE CHECKING PATHWAY, MAKE CERTAIN ALL CONNECTIONS ARE TIGHT, THIS MEANS SPLICE CONNECTIONS AND SCREW TERMINALS. Hopefully if there are any splice connections, you installer put these in either accessible electrical boxes or in in-ground grey electrical cans for easy access.
Make certain the system is grounded properly (not going there here) and DC lightening arrestors installed at the combiner box. And please report on the type of wire and gauge used to go from DC disconnect switch to the charge controller and charge controller to the battery bank. Please report back.
santafedave
Forum Whiz
Posts: 36
Joined: Sat Dec 05, 2020 8:05 pm
My RE system: GS8048-A-300AFCI 8 KW 48V Mate3s with 2 FM100 charge controllers pre wired.
21 Canadian Solar 320 Watt PERC MC4 CS3K-320MS panels.
3 Canadian Solar 325W Module Mono Perc 1000VDC panels.
8 FullRiver AGM DC400-6 Sealed Batteries 415AH 6V L16 size.
Fireraptor quick disconnect.

Re: Burnt wire and arc fault

Post by santafedave »

Thanks PSS. I am in the process of making a telephone appointment with Unbound Solar to talk to a tech. I will have them walk me thru the process you have listed above. I have a question about the fire raptor quick shutoff system. Is there a fusable link somewhere in that system? Anyway I will report back after my appointment with the tech. David.
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