So what did I burn up

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WoodyM
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My RE system: FX3048T FLEXmax FM80

So what did I burn up

Post by WoodyM » Tue Mar 24, 2020 5:20 pm

Just moved my panels and switched out to new batteries. When I turned everything back on, my GFPB tripped after a few seconds. Realized I put my panels in a single string and most likely went over the 150 VDC max. Changed panels to two strings, but GFPB trips every time I turn on the PV array breaker now. Do I need a new PV breaker or GFPB?
Inverter turns on when powered as does the CC when the GFPB is turned back on after some time without the PV breaker on.

fcwlp
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I also install and maintain grid-tied and off-grid systems, details will be given for these system if required
Location: 80 miles NE of Phoenix at 5500'

Re: So what did I burn up

Post by fcwlp » Tue Mar 24, 2020 9:19 pm

The probability of damaging the "cheap" PV input CB or CC output GFDI is low. Most likely you have damaged the more expensive FM80. The FM80 manual gives rather dire warnings to never exceed 150VDC or damage is likely.

I recommend you contact tech support, it may be possible to repair the CC.

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Greg T Fordan
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Re: So what did I burn up

Post by Greg T Fordan » Thu Mar 26, 2020 10:48 am

woody,
Can you provide an electrical diagram of your system installation?
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WoodyM
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Re: So what did I burn up

Post by WoodyM » Thu Mar 26, 2020 10:52 am

Greg T Fordan wrote:
Thu Mar 26, 2020 10:48 am
woody,
Can you provide an electrical diagram of your system installation?
I followed the wiring diagram provided 6 years ago. See attached
EPSON003.PDF
(22.92 KiB) Downloaded 9 times
..

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Greg T Fordan
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Re: So what did I burn up

Post by Greg T Fordan » Thu Mar 26, 2020 11:13 am

so with your modified array configuration, let's assume that the PV voltage is not exceeding 150VDC.

Test your CC alone by leaving the PV breaker off and the battery breaker ON. On CC's main screen, observe the Voltage In (first line) and the Voltage Out (2nd line). Your battery voltage is the voltage out. The Voltage in is PV voltage. Even if the PV breaker is off, it will still create a voltage there due to circuit capacitor action. It will slowly climb up to 50% or 75% of battery voltage if the CC is still good. If it stays at zero, there's nothing you can do but to ask Support for an RMA if the CC is still in warranty. If the Voltage In goes to at least 50%, your CC is still good. You have to find out what's triggering the GFB to trip.
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WoodyM
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Re: So what did I burn up

Post by WoodyM » Thu Mar 26, 2020 12:08 pm

Thanks Greg! measured voltage from the PV strings and was 110.
Running the test now and after 5 min, zero voltage on line 1. Bummer for me but thank you for helping me figure it out.

But now as I am starting to remember all this; when I put the 6 panels in series, it would increase the voltage, not the amperage. so 6 panels @ 36VDS -8.3ADC would have been roughly 180-200 volts, but the amps would have still been in the 30ADC range. Could the volts have done the damage past the breaker?

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Re: So what did I burn up

Post by raysun » Thu Mar 26, 2020 12:16 pm

WoodyM wrote:
Thu Mar 26, 2020 12:08 pm
Thanks Greg! measured voltage from the PV strings and was 110.
Running the test now and after 5 min, zero voltage on line 1. Bummer for me but thank you for helping me figure it out.

But now as I am starting to remember all this; when I put the 6 panels in series, it would increase the voltage, not the amperage. so 6 panels @ 36VDS -8.3ADC would have been roughly 180-200 volts, but the amps would have still been in the 30ADC range. Could the volts have done the damage past the breaker?
Most definitely. The breakers are triggered on current overloads. A voltage overload may cause damage to the breaker with arcing across the contacts, but wouldn't trip it normally.

Exceeding the input voltage limit of the charge controller is a likely cause of failure.

WoodyM
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Re: So what did I burn up

Post by WoodyM » Thu Mar 26, 2020 12:34 pm

Thanks to all, expensive lesson.

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Re: So what did I burn up

Post by pss » Thu Mar 26, 2020 12:45 pm

The lesson to be learned here is to use your meter as much as possible at every point along a circuits right from the panel to the final outlets. Install a panel, ground it, put your meter on the positive and negative. Make sure it works. Do this for every panel. Connect a panel in series (adding up the voltages of the panels, keeping the amperage the same). Don't exceed the maximum voltage allowed by the charge controller. After connecting the panels in series, use your meter and confirm that the measured voltage is what is expected for those panels in series. Connect to the combiner box using a 15-20 amp DC breaker for solar panels. Make sure it is grounded at the panels. Measure the voltage across the DC breaker of your string of panels that were connected in series. Turn off the breaker making sure the voltage after the breaker is zero. Do this for each string of panels in your combiner box (never, never forget to install a DC lightening arrestor in each combiner box. Next run your combiner box output (this is one array string) to a DC disconnect switch, preferably one that accepts a fuse across it (there are specific PV slow burn fuses for solar panel switches) and disconnects that can handle multiple string of arrays, keeping them all electrically separate and turned off with one switch. Measure the voltage past the fuse in the disconnect box or after the switch and test the disconnect switch. Make sure it is zero volts when off. At this point it is most important to use the maximum gauge wire from your disconnect switch to your charge controller to minimize voltage loss over distance. Don't install a larger wire only to find it is too big to fit the charge controller terminals. Measure voltage at the switch and charge controller terminals to confirm electrical continuity. On long runs of conduit, use an electrical box at least every 100 feet with splices to keep from a difficult repair job in the future if wire needs to be replaced or new wire pulled. Use the right size conduit for your gauge or wire and amperage running in the wire. Current casues heat and heat trapped in a too small conduit can cause melting of the wire insulation and arcing and ruin your system.
From the charge controller to your batteries, make sure you have the right DC breakers installed and I also advise a battery terminal fuse on each string of batteries. I even use a marine switch between each string for flexibility. I measure voltage at each point. No surprises should be found. If making battery cables, use fine wire welding cable with the proper insulation. Use only copper terminals with or without flux/solder on them. I prefer to crimp with a hydraulic crimper, 16 ton. This much pressure cold welds the terminal to the cable. No heat soldering is needed. And this avoids areas where current may not want to flow because the solder did not distribute equally everywhere in the terminal lug. This works even for 4/0 cables. Again, measure voltage everywhere and know the specs of your installed equipment. Tighten all connections, wait 10 -20 seconds for them to relax, then tighten to specs again. Seal any weather exposed connects. Use Kopr-Kote on battery terminals to prevent corrosion. When you are confident in all your connections and their continuity, take the plunge to power up in the proper sequence. Proper technique and not cutting corners will let you finish your system and sleep well at night. Plus you will know how to troubleshoot it should the need arise. Lastly, electrical supply stores sell pads of small sticky labels for wires. Buy them and label all your wires at each end and keeps a written record of the labels. You will be glad you did. Same goes for your load panels and outlets - label the breaker and the outlets with the same number: breakers on the left side of load panel are "A", right side "B". Single breaker on left top slot is 1A. Third split breaker on right column of a load panels would be 3B1 (top) and 3B2 (bottom) which shows the slot position, side and top and bottom breaker in a slot. Save time, save grief and save frustration.

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Greg T Fordan
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Re: So what did I burn up

Post by Greg T Fordan » Thu Mar 26, 2020 4:15 pm

Yes, agree with Raysun.
Greg T Fordan
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fcwlp
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Posts: 176
Joined: Wed Jan 22, 2020 9:40 am
My RE system: GS8048A, FM80 w/3,600 W 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 also install and maintain grid-tied and off-grid systems, details will be given for these system if required
Location: 80 miles NE of Phoenix at 5500'

Re: So what did I burn up

Post by fcwlp » Thu Mar 26, 2020 4:26 pm

Greg T Fordan wrote:
Thu Mar 26, 2020 11:13 am
Test your CC alone by leaving the PV breaker off and the battery breaker ON. On CC's main screen, observe the Voltage In (first line) and the Voltage Out (2nd line). Your battery voltage is the voltage out. The Voltage in is PV voltage. Even if the PV breaker is off, it will still create a voltage there due to circuit capacitor action. It will slowly climb up to 50% or 75% of battery voltage if the CC is still good. If it stays at zero, there's nothing you can do but to ask Support for an RMA if the CC is still in warranty. If the Voltage In goes to at least 50%, your CC is still good. You have to find out what's triggering the GFB to trip.
Greg, thanks for the CC troubleshooting tip.

Also as pss and raysun said, measure the voltages before you flip the breakers. For the panels, I test each string prior to the breaker/fuse. The OB Quick Start Guides for the inverters gives a simple commissioning procedure to follow that eliminates these expensive lessons.

raysun
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
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Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: So what did I burn up

Post by raysun » Thu Mar 26, 2020 6:41 pm

One more tip:

When enabling the FM charge controller ALWAYS connect battery power FIRST.

When disabling the FM charge controller ALWAYS disconnect battery power LAST.

WoodyM
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Re: So what did I burn up

Post by WoodyM » Fri Mar 27, 2020 8:09 am

Thanks again for all the follow up advice and tips all!

raysun
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Posts: 1669
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: So what did I burn up

Post by raysun » Fri Mar 27, 2020 8:55 am

WoodyM wrote:
Fri Mar 27, 2020 8:09 am
Thanks again for all the follow up advice and tips all!
Best of luck going forward!

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