Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

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DD153235
Forum Junior Member
Posts: 3
Joined: Mon Aug 10, 2020 11:17 am
My RE system: 30 panels with various watts totaling 8100 watts, Mate3s, Radian series GS8048A Inverter, 2 outback FM80 charge controlers, 16 Rolls flooded L16 - SC 550 Batteries, Generac 8KW Generator
Location: Baja Mexico

Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by DD153235 » Mon Sep 14, 2020 5:38 pm

I live in Baja mexico, 4 hours South of the California border OFF GRID, in this location we get 4 to 5 hours of peak sun, for the last three months average temp has been 98 degrees F, I currently have 21-240 Watt panels, 6-335 Watt panels and 3-345 Watt panels, according to my calculations they provide 8085 total Watts, the first question, is this correct? If yes, the last tech has the following settings on the Mate3s ..... Absorb Voltage 60, absorb time 4.5 hrs, float Volt 55.2, rebulk Volt 50.0, current limit 80.00 and absorb end amps 0. I hope someone can tell me if these setting are correct and what they all mean. Please disregard my ignorance, I'm new at this.
Baja Nick

raysun
Forum Emperor
Posts: 2917
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 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: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by raysun » Tue Sep 15, 2020 9:38 am

Welcome! Most all we off-grid system users seek to become knowledgeable about our systems. This is the spot for that if using Outback gear.

For the sake of completeness, please update your profile with inverter model. Does the system include an Outback Hub? Also, is there a battery monitor in the system? (There should be.)

Regarding the question about solar panels:
The "label wattage" is generally specified at STC - Standard Test Conditions - of 25°C (77°F) and 1kW / sq meter irradiance. Actual output varies with temperature and solar intensity. The higher the ambient temperature, the lower the output. The brighter the sunshine, the higher the output.

Panels listed:
240W x 21 = 5145 watts
335W x 6 = 2010W
345W × 3 = 1035W

So yes, the aggregate panel wattage is > 8kW. However, in practice output is likely less in full sun due to heating.

More important than total wattage of the Photovoltiactic (PV) panels is how they are configured into arrays that feed the FM80 charge controllers. The FM80 is rated at 80 amps charging current, which, charging a 48V nominal battery, would accept a maximum of:
48V x 80A = 3840W. (Safely rounded up to 4000W in most cases.) The maximum panel voltage that an FM80 can accept is 150V.

Do you know how the two PV arrays are configured? Are all the 240W panels on one FM80 and the rest of the PV panels on the other?

Do you know the specific models of the solar panels?

Regarding battery charging:

If you don't have it, download the Rolls battery manual:

https://rollsbattery.com/public/docs/us ... Manual.pdf

The set charging voltages and absorb time look about right. However, charging voltages vary with battery temperature. Most advanced systems use temperature compensated charging to automatically adjust the voltages during the charge cycle. Is there an Outback Remote Temperature Sensor (RTS) attached to the side of one of the battery monoblocks?

provo
Forum Czar
Posts: 525
Joined: Thu Jul 27, 2006 4:34 pm
My RE system: Sixteen Evergreen EC-120
(4 strings, total 1920W)
Eight Rolls S-550 (2 strings, total ~800Ah @ 24V)
One FM80
One VFXR3524A
Hub 10
Mate3s
FNDC and Trimetric
Location: Sierra foothills

Re: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by provo » Tue Sep 15, 2020 11:07 am

DD153235 wrote:
Mon Sep 14, 2020 5:38 pm

Absorb Voltage 60, absorb time 4.5 hrs, float Volt 55.2...
Check out the Rolls Manual online at https://www.rollsbattery.com/wp-content ... Manual.pdf

On p. 13 there's a table showing recommended setpoints. The 60V is what they recommend for absorb, but they recommend 54V for float. Read the whole section on Flooded Batteries -- it's more than you ever wanted to know! The 20-hour capacity of each battery is actually 487Ah, for a total of 974Ah with the two strings. Your battery should get something like 127A of charging current (13%) and your panels are capable of 168A at 48V, so you might want to do something to dial it back a bit in bright sun...

I've had good luck with Rolls FLA's over the past 13 years. I absorb for 3h, but 4.5h might be OK -- do you have a good hydrometer?

DD153235
Forum Junior Member
Posts: 3
Joined: Mon Aug 10, 2020 11:17 am
My RE system: 30 panels with various watts totaling 8100 watts, Mate3s, Radian series GS8048A Inverter, 2 outback FM80 charge controlers, 16 Rolls flooded L16 - SC 550 Batteries, Generac 8KW Generator
Location: Baja Mexico

Re: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by DD153235 » Tue Sep 15, 2020 12:13 pm

Thank you for responding, the 21 panels are TRINA TSM-235PA05 and according to the tag they are 235W not 240, the 6 335W panels are JA Solar JAP72S09, the 3 345W panels are also JA Solar JA72S10. As far as the array, I don't know how they are set up, for what It's worth, the readings on both charge controllers are very similar all day. On the Mate3s settings there is a battery monitor, not sure about an outback hub,there is a black box with green lights going up and down, is that the hub? I will update my profile with the inverter model, GS8048A, finally there is a temp. sensor on one of the batteries.
I hope this helps,
Baja Nick

provo
Forum Czar
Posts: 525
Joined: Thu Jul 27, 2006 4:34 pm
My RE system: Sixteen Evergreen EC-120
(4 strings, total 1920W)
Eight Rolls S-550 (2 strings, total ~800Ah @ 24V)
One FM80
One VFXR3524A
Hub 10
Mate3s
FNDC and Trimetric
Location: Sierra foothills

Re: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by provo » Tue Sep 15, 2020 12:45 pm

DD153235 wrote:
Tue Sep 15, 2020 12:13 pm

On the Mate3s settings there is a battery monitor, not sure about an outback hub,there is a black box with green lights going up and down, is that the hub?
The black box with green LED's is the hub.

I don't remember if the Battery Monitor shows up in settings if you don't have one. Find this screen:

IMG_0141.jpeg

If the battery icon in the upper right has a percentage next to it, you have a FlexNet DC battery monitor -- that would be excellent!
You can see more details (if it's there) by pushing the second soft key from the left at the bottom (under the 29.4V in the picture.)

fcwlp
Forum Czar
Posts: 527
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: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by fcwlp » Tue Sep 15, 2020 8:37 pm

DD153235 wrote:
Tue Sep 15, 2020 12:13 pm
Thank you for responding, the 21 panels are TRINA TSM-235PA05 and according to the tag they are 235W not 240, the 6 335W panels are JA Solar JAP72S09, the 3 345W panels are also JA Solar JA72S10. As far as the array, I don't know how they are set up, for what It's worth, the readings on both charge controllers are very similar all day.
Lets start with your PV array design to ensure that you are getting an optimal PV harvest. The PV panels are connected together in strings, based on your panel counts of 21, 6 and 3 it looks like you installer put them in strings of 3 panels which was ok for the Trina panels but likely creates too high of a Voc (Voltage Open Circuit) for the JAP72S09 and likely the JA72S10 (which I can not find a datasheet on but looks like it is a 72 cell panel so similar to JAP72S09). The JAP72S09-335 has a Voc of 46.1V which for 3 panels in series is 138.3V. The FM80 has max V of 150V and caution is indicated at 145V. For a similar module with a 46.1V Voc at 10C (50F) you are at 145V and at 0C (32F) you are 150V. The 345W panel will likely have a higher Voc so you are in an area that will shutdown your FM80. If you get below 10C, I would recommend dropping one panel and re-wiring as 4 strings of 2 panels.

I expect the 21 Trina modules were installed at an earlier date. You have 4,935W which per the Outback string sizing tool puts you into the "caution" region.

My assumption is that one FM80 is connected to the Trina module array and one FM80 is connected to the JA Solar array. Given that the Trina array has 4,935W and the JA Solar array has 3,045W I would not expect the FM80s to have similar values.

There will be a "combiner box" near each group of modules. If you open up the Trina combiner box you should see 7 breakers or fuses holders. If you open up the JA Solar box I believe you should see 3 breakers or fuses. For each combiner box, report if all the breakers are in the up position. If there are fuses do not open them as you will have a DC arc fire.

Take a picture of the display for each CC and post.

I probably should have asked this first; what your comfort level is in working with electrical circuits? Do you have a voltmeter? Do you have a clamp-on DC ammeter?

DD153235
Forum Junior Member
Posts: 3
Joined: Mon Aug 10, 2020 11:17 am
My RE system: 30 panels with various watts totaling 8100 watts, Mate3s, Radian series GS8048A Inverter, 2 outback FM80 charge controlers, 16 Rolls flooded L16 - SC 550 Batteries, Generac 8KW Generator
Location: Baja Mexico

Re: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by DD153235 » Mon Sep 21, 2020 3:10 pm

Hello, very frustrated, at not being able to access the forum for the past 4 days, I see I'm not alone with that issue, got lucky today, in response to your suggestions,(1) the mate 3s settings has a field " battery monitor with option to select battery set up ,with various fields that are blank, shunts enable and Flex net relays. (2) clicking on the battery icon brings up battery status and the current readings are " Battery 52.8 V 33C, Min 48.0 V 6.51, Max 52.0 V 8:55. (3) as for the comfort level in dealing with electrical wires is Zero. Finally I don't understand being in the area of shut down the FM 80 and the outback string sizing tool putting me in the caution region, please explain in the most elementary way.
Thanks
Baja Nick

provo
Forum Czar
Posts: 525
Joined: Thu Jul 27, 2006 4:34 pm
My RE system: Sixteen Evergreen EC-120
(4 strings, total 1920W)
Eight Rolls S-550 (2 strings, total ~800Ah @ 24V)
One FM80
One VFXR3524A
Hub 10
Mate3s
FNDC and Trimetric
Location: Sierra foothills

Re: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by provo » Tue Sep 22, 2020 9:46 am

1. How long have you been living with this system, and how has it been performing for you?
2. Do you regularly water your batteries?
3. Do you have a hydrometer to measure the specific gravity of the electrolyte in your battery cells?
4. Have you downloaded and read all the spec sheets and manuals for all the system components?
5. Do you still have access to the tech who worked on your system most recently?
6. Is there a specific problem in your system that needs solving?

raysun
Forum Emperor
Posts: 2917
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 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: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by raysun » Tue Sep 22, 2020 10:46 am

Hola Nick, welcome back.

As you might have gathered, there's a lot to a solar power system with battery storage. The flood of details can be overwhelming. Best to take it one topic at a time.

Let's start with Photovoltiactic (PV) Solar Panels and Charge Controllers.

In an Off-Grid system, the battery stores DC power (charge) and delivers it to loads. The most common load is the inverter. As the battery is drained of charge, it must be recharged. Battery charging is the primary function of the PV panels and Charge Controller.

PV panels absorb sunlight and convert it to DC electric energy. There are several aspects to PV panels that must be grasped in order understand the system. PV panels can be likened (roughly) to a generator. PV panels have a rated output, measured in Watts. They have a rated output voltage measured in DC Volts, and a rated output current measured in DC Amps. Volts x Amps = Watts.

The ratings, printed on a sticker on the back of the panels, are measured in the lab using Standard Test Conditions (STC). How much power a PV panel puts out in the "real world" is governed by environmental factors.

Several ratings are printed on the sticker, four of which are most important:

V(oc) - Voltage in an open circuit. This is the measurement of voltage with the panel disconnected from a load. It is considered the highest voltage the panel can generate.

I(sc) - Current in a short circuit. This is amperage measured with the + and - terminals directly connected. It is a measure of the maximum current the panel can generate.

V(mp) - Voltage at maximum power. As the panel produces power, its voltage drops from V(oc). V(mp) shows the expected output voltage at maximum power output.

I(mp) - Current at maximum power. As the panel produces power, the output current rises. I(mp) shows the expected amperage at maximum power output.

The values above are measured in highly controlled conditions - at a specific temperature (77°F) and light intensity (1000W/sq. meter). As the temperature rises, power output goes down. As sunlight is less intense, power output likewise goes down. The opposite happens when temperature declines and light intensity rises.

Why do we care about these ratings? Because we want to be able to design a PV panel array that has sufficient solar power harvest to satisfy our daily electric demands.

The first step is collecting solar power that is converted to DC electric energy and using that energy to charge our battery. The Charge Controller is the device that accepts the "raw" DC electrical energy from the PV panels, and converts it to a controlled charge suitable for battery charging.

In order for the PV panels, charge contoller, and battery to work together, they must be carefully matched and configured. In the simplest terms, the charge drawn from the battery, must be replaced. If 10 kilo-watt hours (kWH) of power is drawn from the battery, then 10kWH (plus some extra) must be put back.

Starting with the PV panel array. Its output voltage must be higher than the highest battery voltage in order to supply sufficient charging voltage. The charge controller will take the higher voltage and convert it to the lower voltage needed for proper charging. Further, the array output voltage must be less than the maximum rated voltage the charge controller can safely accept. In the case of your system, the PV array must put out at least 65V, but less than 150V.

How is the array configured to do this? By wiring panels in series, as voltages add. If the PV panels, for example, have a V(mp) of 35V, then two panels wired in series would deliver 70V at maximum power output, just enough to cover charging requirements. Three panels in series would deliver 105V.

When wiring the panels in series, care must be taken that the output voltage never exceeds the maximum rated input voltage of the charge controller. The maximum voltage is taken from the V(oc) rating. If our panel has a V(oc) of 40V, then three in series would equal 120V, safely under the 150V maximum of the controller. If four were wired in series, the 160V rating carries the potential to damage the controller.

The array voltage connected to the charge controller can be seen on the front panel as the IN voltage. The highest voltage the array has put out can be seen by navigating to the Stats menu on the charge controller.

Series strings may be wired in parallel to increase the output current. The maximum charging current the FM80 controller can safely handle is 80 Amps.

Since input current will be lower than charging current, its easiest to calculate the total array size in watts. Assuming a nominal battery voltage of 50V, the maximum array power is 50V x 80A = 4000W. If the PV panels have a rating of 250W, then 4000W / 250W = 16 panels maximum.

That's a lot of info to digest. Next, we can explore the charge controller in greater detail. For now, look at the IN and OUT voltage and amperage on the controller display to get an idea of the activity. Also, dig into the Stats on the controller to see the maximum voltage and power that has been recorded.

fcwlp
Forum Czar
Posts: 527
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: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by fcwlp » Tue Sep 22, 2020 4:00 pm

DD153235 wrote:
Mon Sep 21, 2020 3:10 pm
(3) as for the comfort level in dealing with electrical wires is Zero.
There are several basic rules when working with solar and home wiring circuits:
1) Turn off the power to the box/panel you are working on. Some boxes like the Radian GSLC will still have battery voltage present in them, so still be careful.
2) Verify the power is off using a voltmeter. If you do not have a voltmeter, get one that can measure AC & DC voltages and has a clamp-on AC & DC ammeter. This is a reasonable multi-meter https://www.homedepot.com/p/Klein-Tools ... 312649921.
3) Use insulated tools, to avoid that accidental shorting of two terminals that may be energized. Working on battery terminals is one area to be very careful with accidental tool shorts.
4) Wear rubber soled shoes and work with only one hand as much as feasible, keeping the other tucked behind your back. This ensures that the current does not flow across your heart. Use two hands when working on the battery terminals as voltage is relatively low.
DD153235 wrote:
Mon Sep 21, 2020 3:10 pm
Finally I don't understand being in the area of shut down the FM 80 and the outback string sizing tool putting me in the caution region, please explain in the most elementary way.
Raysun did a good job of explaining the basics of the PV array design.

The array voltage may get too high when it is cold out for the JA Solar panels and cause the FM80 to shutdown.
- What is your [correction, minimum not maximum] lowest temperature?
- How long have the JA Solar panels been operational?

Takes some pictures of the FM80s at noon on a sunny day and post them. Also open up the combiner boxes and post the pictures.
Last edited by fcwlp on Thu Sep 24, 2020 8:29 am, edited 1 time in total.

randallxski
Forum Member
Posts: 24
Joined: Thu Jul 27, 2017 6:03 am
My RE system: Primary System:
Radian 8048A Inverter
24 Rolls S-1860 2v Batteries
3 FlexMax 80 Charge Controllers
42 250W AmeriSolar Solar Panels
Mate3s / Outback Hub / FlexNet DC
CAT C3.3 55KW Generator
Occasional Power from Electric Company (~5 hrs every 48 hours)
Location: Jacmel, Haiti
Contact:

Re: Tired of being at the mercy of local solar techs, want to learn enough to manage/maintain my system

Post by randallxski » Wed Sep 23, 2020 6:48 pm

I'm following this. The information you all have about how these systems operate is amazing! Thanks for being so willing to share. :smile:

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