help with 1-line diagram

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Heimhenge
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My RE system: 9 CSUN 390W panels for 3.51 kW
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Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

help with 1-line diagram

Post by Heimhenge » Wed Mar 04, 2020 5:21 pm

New OB system owner here and still learning. Replaced my 20 yo (self installed) Trace system and upgraded panels and battery. The technology has really evolved over 20 years. The new system is wired and working, but I've been struggling with its 1-line diagram. I've had some contradictory answers from the installer who otherwise did good work. Here's my questions:

1. Should there be a fuse or breaker between the FM100 and battery?
2. That "transfer switch and breaker" is confusing. The installer claims it's actually a breaker and will trip if needed. Is that right? What condition could possibly cause it to switch the subpanel load back to the grid? I know I can do it manually, since I did that a couple times with my Trace system. But this is a new 2-pole transfer switch. Still, something doesn't sound right here. The installer admits he doesn't do many hybrid systems.

I wasn't even sure how to show that transfer switch in the schematic, so what you see is my best guess. :)

If you see anything else questionable, please advise. Thanks. Here's the 1-line:
1-line-v3A.jpg

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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: help with 1-line diagram

Post by fcwlp » Wed Mar 04, 2020 8:20 pm

Does your system have a GSLC (GS Load Center) below the Radian? As you have a FNDC, my guess is that you do have a GSLC. Within the GSLC there is breaker for the PV + input to the CC and a breaker for the Batt+ coming from the CC. The FM100 is a 300V capable CC, so the breakers must be rated for 300V. Do you know what your string voltages are?

There is also an AC transfer switch function using interlocked breakers in the GSLC. This is the set of breakers at the top of the GSLC with a red interlock block. Also the input breaker to the inverter in the GSLC I expect is 175A as the GS8048A systems use two 175A breakers.

I am surprised that APS (local power company) approved the 1-line as it does not show the main breaker being de-rated to 175A as required by NEC.

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Heimhenge
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Posts: 123
Joined: Sun Jan 26, 2020 10:28 am
My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Wed Mar 04, 2020 10:25 pm

I don't think I have a GSLC. The original transfer switch was single pole. The installer had to get a double pole to replace it. This is what it looks like:
transfer-switch.jpg
There wasn't enough room to install the full OB integrated system. The GS4048A, FM100, FMDC, and MATE3s, were mounted separately in the available space. It looks like this:
power-panel-new.jpg
I have 3 strings of 3 panels with each string pushing 144.3VDC (open circuit voltage at STC).

APS approved the original 1-line back around 2000. They tell me I don't need any further intervention or approval on their part as long as I'm only upgrading an existing approved system.

So do you see any problems with this 1-line? And do I have that transfer switch correct in the schematic?

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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (2x7) Talesun 275W (DC array input to SB charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: help with 1-line diagram

Post by Mike Curran » Thu Mar 05, 2020 7:15 am

Heimhenge wrote:
Wed Mar 04, 2020 5:21 pm
1. Should there be a fuse or breaker between the FM100 and battery?
Yes, but it need not be rated for 300 V DC. Something like OB's PNL-100-DC - 100 Amp, 125Vdc, 5/16” stud terminals should work (http://outbackpower.com/products/integr ... anel-mount) . It may look like one isn't needed because he has a 100A breaker in front of the FM100, but remember that breaker is on a higher voltage circuit than exists on the output side of the FM100, where voltage is only 48 volts. Btw, I think that 100A manual array disconnect is oversized, it needs to be more like 60A since each of your 3 strings isn't likely to exceed 20A each. Same comment applies to the 3, 30A combiner box breakers, altho' will probably work as is.
Heimhenge wrote:
Wed Mar 04, 2020 5:21 pm
2. That "transfer switch and breaker" is confusing. The installer claims it's actually a breaker and will trip if needed. Is that right? What condition could possibly cause it to switch the subpanel load back to the grid? I know I can do it manually, since I did that a couple times with my Trace system. But this is a new 2-pole transfer switch. Still, something doesn't sound right here. The installer admits he doesn't do many hybrid systems.
I have a couple of this type xfer switch in my systems, and, yes, it will trip if there's an overcurrent condition. However, since the switch has a mechanical interlock between the grid and inverter sides, it may or may not close the grid side breaker if the inverter side trips. I know with mine it's possible to have both sides "open" at the same time, but not both sides closed at once.

Hope this helps. - Mike

PS sorry, got carried away with the colors :smile:
PPS edited to correct breaker sizing/spec in answer to #1.
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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: help with 1-line diagram

Post by fcwlp » Thu Mar 05, 2020 7:24 am

You are correct, there is no GSLC.

On the transfer switch, the breakers will trip if there is an overload but there is no automatic transfer function.

Starting at your PV array:
  • The combiner box currently has 3 30A breakers. Per CSUN 390 datasheet the maximum size should be 20A and based on the Isc of 10.21A for the string you should be using a 15A breaker/fuse. The Voc at STC of 144.3V is going to likely exceed 150V at your minimum temperature which is the maximum rating of the Midnite PV breakers that are likely being used. Correct design would be using fuse holders with 15A fuses or 300VDC breakers.
  • The Isc of the array at 30.63A with 15A or 20A string protection is consistent with using a #6AWG output from the combiner box
  • The 100A breaker also needs to be 300VDC rated. I would replace with a 60A breaker.
  • The FM100 will output 100A. Your #6 AWG wire is too small and should be replaced with #2 AWG as it is running through conduit.
  • There should be a breaker on the output of the FM100. With the built in GFI or AFCI, the breaker on the output must be rated for 300VDC and the standard size is 125A. Midnite Solar has a small box that you can put this breaker in

Mike Curran
Forum Emperor
Posts: 1740
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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (2x7) Talesun 275W (DC array input to SB charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: help with 1-line diagram

Post by Mike Curran » Thu Mar 05, 2020 7:27 am

With the built in GFI or AFCI, the breaker on the output must be rated for 300VDC and the standard size is 125A. 
fcwlp - Good to see we are in agreement on most, but why is 300V rating needed when voltage level there is only around 48 volts?
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fcwlp
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Posts: 479
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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: help with 1-line diagram

Post by fcwlp » Thu Mar 05, 2020 7:35 am

Mike Curran wrote:
Thu Mar 05, 2020 7:27 am
With the built in GFI or AFCI, the breaker on the output must be rated for 300VDC and the standard size is 125A. 
fcwlp - Good to see we are in agreement on most, but why is 300V rating needed when voltage level there is only around 48 volts?
My understanding is that if a fault occurs there is a possibility of the array voltage going thru the output. This is one of the reasons that Outback does not recommend putting an FM100 into a system that already has FM60s or FM80s with GFI protection. This is explained in this app note better than I can do. http://www.outbackpower.com/downloads/d ... p_note.pdf.

Mike Curran
Forum Emperor
Posts: 1740
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 GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy 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 (2x7) Talesun 275W (DC array input to SB charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: help with 1-line diagram

Post by Mike Curran » Thu Mar 05, 2020 7:43 am

Thanks! I see that in the app note: "Replace PNL-GFDI-80, PNL-GFDI-80D or PNL-GFDI-80Q with circuit breakers as the
FM100 has internal Ground Fault Protection (PNL-125-300VDC)"
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

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Re: help with 1-line diagram

Post by EMCF » Thu Mar 05, 2020 8:43 am

My take. Everything looks good, with the exception of missing disconnect means between FM100 and batteries. What I recommend is remove the existing breaker that I highlighted and place it between FM100 and batteries. You do not have to physically move the breaker, of course. Just modify the connection. The 3 breakers in the combiner box is good enough PV array protection and there is no need to put another one in series.
5mar2020.JPG
The disconnect switch between AC Out and Grid is manually operated, and it is a breaker, too.
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Heimhenge
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Posts: 123
Joined: Sun Jan 26, 2020 10:28 am
My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Thu Mar 05, 2020 9:48 am

Thanks to all for the feedback on my 1-line. It all makes sense to me. I'll forward a distilled version of your responses to the installer. He OKed that 1-line, so either he doesn't understand 1-lines, or he's gonna need to make some changes to the system.

Like I said, the system seems to be functioning well, my battery is fully charged, and I'm selling excess to the grid. But if y'all are correct, there's some serious safety and code issues here. I'll be post back with the installer's response. He's outa town till Monday.

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Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: help with 1-line diagram

Post by raysun » Thu Mar 05, 2020 10:21 am

EMCF wrote:
Thu Mar 05, 2020 8:43 am
My take. Everything looks good, with the exception of missing disconnect means between FM100 and batteries. What I recommend is remove the existing breaker that I highlighted and place it between FM100 and batteries. You do not have to physically move the breaker, of course. Just modify the connection. The 3 breakers in the combiner box is good enough PV array protection and there is no need to put another one in series.
5mar2020.JPG

The disconnect switch between AC Out and Grid is manually operated, and it is a breaker, too.
I'm going to take gentle exception to moving the 100A breaker's function. While 3 disconnects in the combiner box can be opened to remove PV feed from the FM100. It may not be convenient. Also, removing the 100A breaker means there is then no protection for the wiring between combiner and charge controller. While its low risk there'd be an issue, there's not zero risk. Taking future evolution into account, (nobody decides to remove panel capacity, only add to it) disconnecting at the combiner boxes becomes even more inoperable. I have 12 disconnects in 2 combiner boxes. I would consider it very poor operational practice to be required to open them all for servicing the charge controllers. Having a single breaker to disconnect all PV feed at the point of service for the FM100 is cheap insurance.

Adding a 100A disconnect between charge controller and battery is clearly called for. Since the FM100 has built-in arc fault protection, it need not be anything other than a standard 100A DC panel mount breaker.

TBH, if there's room in the DC panel to mount another breaker, it will be faster, cheaper, and ultimately more reliable to add a new disconnect than to repurpose an existing one that's serving an important function.

Just my $0.02.

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Heimhenge
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Posts: 123
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My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Thu Mar 05, 2020 11:19 am

Good point about the convenience for array disconnection. I mean, the array is on a flat roof with stairs for access, but the weather isn't always convenient. :) And that breaker is already installed. Don't really see where the risk would come from in removing that breaker though ... maybe if a meteor hits the combiner box and shorts all the positive leads together? But seriously, where do you see any risk?

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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: help with 1-line diagram

Post by raysun » Thu Mar 05, 2020 11:56 am

All the positives are already combined. That's what the combiner box does. No meteorite needed. ;)

Take a look at pretty much any circuit diagram for a well designed system, and you will find a breaker everywhere there is a change on required ampacity, or cabling that needs protecting.

I can't predict risk for your system, or your tolerance for assumption of same. I could speculate - a short on the input board of the charge controller maybe, etc. In fact, I'd say there's minuscule risk, until there isn't. So there's no need for that breaker, until there is. A $50 breaker, in place and serving a function, is cheap insurance.

To each his own. I have that breaker in place, and always would without giving it another thought.

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Re: help with 1-line diagram

Post by EMCF » Thu Mar 05, 2020 12:28 pm

raysun wrote:
Thu Mar 05, 2020 10:21 am
Adding a 100A disconnect between charge controller and battery is clearly called for. Since the FM100 has built-in arc fault protection, it need not be anything other than a standard 100A DC panel mount breaker.

TBH, if there's room in the DC panel to mount another breaker, it will be faster, cheaper, and ultimately more reliable to add a new disconnect than to repurpose an existing one that's serving an important function.

Just my $0.02.

I can go with Raysun's 2 cents ;-)
And to emphasize, in the hierarchy of picking the more important thing to take action at this time, first priority is the addition of that breaker between FM100 and the battery. The way it is wired at this time, you can't completely electrically isolate the FM100 unless you make disconnection from the battery terminals.
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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: help with 1-line diagram

Post by raysun » Thu Mar 05, 2020 12:40 pm

EMCF wrote:
Thu Mar 05, 2020 12:28 pm
raysun wrote:
Thu Mar 05, 2020 10:21 am
Adding a 100A disconnect between charge controller and battery is clearly called for. Since the FM100 has built-in arc fault protection, it need not be anything other than a standard 100A DC panel mount breaker.

TBH, if there's room in the DC panel to mount another breaker, it will be faster, cheaper, and ultimately more reliable to add a new disconnect than to repurpose an existing one that's serving an important function.

Just my $0.02.

I can go with Raysun's 2 cents ;-)
And to emphasize, in the hierarchy of picking the more important thing to take action at this time, first priority is the addition of that breaker between FM100 and the battery. The way it is wired at this time, you can't completely electrically isolate the FM100 unless you make disconnection from the battery terminals.
Yep, that Controller <-> Battery disconnect needs to be added.

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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: help with 1-line diagram

Post by fcwlp » Thu Mar 05, 2020 8:24 pm

raysun wrote:
Thu Mar 05, 2020 12:40 pm
Yep, that Controller <-> Battery disconnect needs to be added.
Also increase the wire size to preferably #2 AWG. Breaker should be a 125A 300V which is the standard Outback FM100 GSLC configuration as I noted earlier along with the application note.

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Heimhenge
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Posts: 123
Joined: Sun Jan 26, 2020 10:28 am
My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Tue Mar 10, 2020 3:01 pm

fcwlp wrote:
Thu Mar 05, 2020 8:24 pm
raysun wrote:
Thu Mar 05, 2020 12:40 pm
Yep, that Controller <-> Battery disconnect needs to be added.
Also increase the wire size to preferably #2 AWG. Breaker should be a 125A 300V which is the standard Outback FM100 GSLC configuration as I noted earlier along with the application note.
Why #2 AWG? And why a 125A breaker? The array is rated 3.5 kW. I've seen it hit 3.9 kW during a cloud edge event in cold weather. Only lasted maybe 10-25 seconds. So let's say 4 kW output just to make the numbers easy. At 4 kW the FM100 output to the battery would be around 4kW/50V = 80A. Don't you think the 100A breaker and #3 AWG would suffice? Getting some pushback from the installer on this change. He was OK with all the other recommended changes. Take a look at the latest version of my 1-line.
1-line-v3B.jpg

raysun
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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: help with 1-line diagram

Post by raysun » Tue Mar 10, 2020 3:13 pm

Heimhenge wrote:
Tue Mar 10, 2020 3:01 pm
fcwlp wrote:
Thu Mar 05, 2020 8:24 pm
raysun wrote:
Thu Mar 05, 2020 12:40 pm
Yep, that Controller <-> Battery disconnect needs to be added.
Also increase the wire size to preferably #2 AWG. Breaker should be a 125A 300V which is the standard Outback FM100 GSLC configuration as I noted earlier along with the application note.
Why #2 AWG? And why a 125A breaker? The array is rated 3.5 kW. I've seen it hit 3.9 kW during a cloud edge event in cold weather. Only lasted maybe 10-25 seconds. So let's say 4 kW output just to make the numbers easy. At 4 kW the FM100 output to the battery would be around 4kW/50V = 80A. Don't you think the 100A breaker and #3 AWG would suffice? Getting some pushback from the installer on this change. He was OK with all the other recommended changes. Take a look at the latest version of my 1-line.
1-line-v3B.jpg
100ADC disconnect and 3AWG @ 90°C copper wire should be fine AFIK. Your electrician would be the best to weigh in on what the local codes require.

Lots of folks derate the wiring to 80% in conduit, and 3AWG doesn't quite get to 100A derated that way. 2AWG does, and may be the reason for the recommendation.

The main issue would not be the FM100 feeding current to the battery, but the battery feeding current to the FM80 in the event of a short in the equipment.

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Heimhenge
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Posts: 123
Joined: Sun Jan 26, 2020 10:28 am
My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Tue Mar 10, 2020 4:39 pm

raysun wrote:
Tue Mar 10, 2020 3:13 pm
Heimhenge wrote:
Tue Mar 10, 2020 3:01 pm
fcwlp wrote:
Thu Mar 05, 2020 8:24 pm

Also increase the wire size to preferably #2 AWG. Breaker should be a 125A 300V which is the standard Outback FM100 GSLC configuration as I noted earlier along with the application note.
Why #2 AWG? And why a 125A breaker? The array is rated 3.5 kW. I've seen it hit 3.9 kW during a cloud edge event in cold weather. Only lasted maybe 10-25 seconds. So let's say 4 kW output just to make the numbers easy. At 4 kW the FM100 output to the battery would be around 4kW/50V = 80A. Don't you think the 100A breaker and #3 AWG would suffice? Getting some pushback from the installer on this change. He was OK with all the other recommended changes. Take a look at the latest version of my 1-line.
1-line-v3B.jpg
100ADC disconnect and 3AWG @ 90°C copper wire should be fine AFIK. Your electrician would be the best to weigh in on what the local codes require.

Lots of folks derate the wiring to 80% in conduit, and 3AWG doesn't quite get to 100A derated that way. 2AWG does, and may be the reason for the recommendation.

The main issue would not be the FM100 feeding current to the battery, but the battery feeding current to the FM80 in the event of a short in the equipment.
OK, I get that thanks. I don't think the derating is a worry since it's a single cable in a 1" run of 3/4" flex, then to "open air" inside the DC panel. And this is all in an interior space where the temps stays 72-80 F. What I'm puzzled about is the #3 AWG run in that 1-line (between the FM100 and battery).

What I see in the battery room is two 3/0 cables running through the wall into the back of the DC panel. How and where does that #3 AWG interface with the battery? I am definitely missing something here. I would expect the cable from the battery to the FM100 to be the same gauge all the way.

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Re: help with 1-line diagram

Post by fcwlp » Tue Mar 10, 2020 9:10 pm

Heimhenge wrote:
Tue Mar 10, 2020 4:39 pm
What I see in the battery room is two 3/0 cables running through the wall into the back of the DC panel. How and where does that #3 AWG interface with the battery? I am definitely missing something here. I would expect the cable from the battery to the FM100 to be the same gauge all the way.
The positive 3/0 cable goes from the + battery terminal to the 250A DC breaker. The #3 AWG from the FM100's output breaker will also go to the same location on the 250A breaker or directly to the battery.

I missed your previous post on breaker size and wire size. Since you are not utilizing the full capability of the FM100, going with a 100A breaker and #3 AWG wire is o'k. If you were running the full 100A capability then I would still recommend a 125A breaker and #2 AWG wire.

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Re: help with 1-line diagram

Post by Heimhenge » Tue Mar 10, 2020 9:17 pm

So are you saying this 1-line is correct?
1-line-v3B.jpg

fcwlp
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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: help with 1-line diagram

Post by fcwlp » Tue Mar 10, 2020 9:51 pm

The one-line is o'k.

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Heimhenge
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Posts: 123
Joined: Sun Jan 26, 2020 10:28 am
My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Tue Mar 10, 2020 10:33 pm

Thanks. I'm gonna open up that DC box tomorrow and take a photo. I really need to know which cables run where. Stand by.

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Posts: 123
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My RE system: 9 CSUN 390W panels for 3.51 kW
UniStrut PV rack on a flat roof
Midnight Solar MNPV3 combiner box w/ breakers
Outback Radian GS4048A-01 inverter
Outback FM100 charge controller
Outback FLEXnet DC monitor
Outback MATE3s system controller
Outback Hub
Trace DC breaker and shunt box
Lifeline GPL-8DL x4 = 12.2 kWh @ 48 volts
Running OpticsRE since March 2020
Location: 30 miles north of Phoenix @ elevation 2200 ft

Re: help with 1-line diagram

Post by Heimhenge » Wed Mar 11, 2020 1:01 pm

OK, so this is what the interior of that DC panel looks like:
DC-panel.jpg
And for reference, here's the 1-line we've been discussing:
1-line-v3B.jpg
I was curious about that (soon to be) #3 wire from the FM100 and how it got to the battery, as shown in the 1-line. It's a little hard to follow an individual cable in all that "spaghetti" but by zooming and boosting the gamma a bit, it appears the cable in question (color black) connects to the battery by junctioning with the heavy 3/0 cable on a bus inside the DC panel.

So I guess, in terms of functionality, the 1-line is indeed correct as fcwlp judged. The installer will be up here next week to replace the existing #6 AWG cable with #3 AWG, as well as add that 100A breaker between the FM100 and battery.

Thanks again to all who helped me sort this out.

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Posts: 479
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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: help with 1-line diagram

Post by fcwlp » Wed Mar 11, 2020 3:37 pm

Heimhenge wrote:
Wed Mar 11, 2020 1:01 pm
I was curious about that (soon to be) #3 wire from the FM100 and how it got to the battery, as shown in the 1-line. It's a little hard to follow an individual cable in all that "spaghetti" but by zooming and boosting the gamma a bit, it appears the cable in question (color black) connects to the battery by junctioning with the heavy 3/0 cable on a bus inside the DC panel.
The bus on the right side about 2/3 of the way up is a negative bus. The 3/0 negative battery cable coming into the shunt on the bottom right is obvious. I am not sure what the heavier wire (maybe #2 AWG) coming into the bottom of that negative bus is.

It appears the breaker at the top right is your PV input breaker, is this correct? If so it looks like the PV red and black appear from the same place with the red going to the breaker and black to the FM100.

Coming out of the conduit connecting to the FM100, I see a red and black going to the conduit at the top right. This appears to be the FM100 output to the battery, is this correct? I do not see any black wire connecting the negative bus.

If you can label the wires that your are looking at, that would help.

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