Please help!! I'm at wits end. Diagnose "open circuit"?

[BulldawgSolar]

I have constructed a 48v off-grid system:

- 48v Sigineer 3000w offgrid inverter/SCC/MPPT/
- 8 12v/150ah LiOP batteries (2 x 4 in series)
- 6 string Eco-Worthy combiner box
- 10- 100w/12v panels (2 x 5 in series)
- 9- 210w/12v panels (3 x 3 in series)

The system works great except that I can't get any PV input from the 210w panels. I've tested each panel individually. tested the wires and connections. i've tried different connection boxes. It seems that only the 100w panels are producing (average 750w). The max potential of the system is 2,880w.

I have an extra 4 string Eco-Worthy combiner box and a Victron 150/30 MPPT and I attempted to hooked the 210w panels to the Victron and leave the 100w panels on the Sigineer and connect the PV Outputs from each to the batteries using 2 bus bars.

What I uncovered was almost max Volts but 0 Amps (ergo 0 Watts). In troubleshooting, it said that the MPPT was not connected to or reading the batteries, but it was showing the same voltage as my stand alone battery meter so it must be connected. It also said the Volts with no Amps means "Open Circuit", but how can that be?!?!

The Victron is grounded. The 3 3 x 210w panels are hooked up correctly. I also tried hooking different wires to different sets of panels, hooking different panels together, swapping from 3 strings of 3 to 1 string to 2 strings. I also tried 2 panels hooked in parallel and the voltage dropped in half but still no Watts.

No fuses are blown otherwise the 2 5 x100w wouldnt be working.

Side note: last week when I 1st set up the system and had only 2 5 x100w and 2 3 x 210w I did register 1,600w PV input during ideal conditions which I believe was the result of the 2 100w strings and 1 of the 2 210w strings working at almost max. Also, at times, the new string of 3 x 210w seems to actually make the PV input Watts drop when plugged.

Please help!!

 

[sunshine_eggo]

Please provide PV panel specifications

Please clarify:
2 x 5 in series means 5 panels in series, two sets of 5 in parallel, i.e., 5S2P?
3 x 3 in series means 3S3P?
You have these two arrays in parallel with each other into the same MPPT?

 

[Samsonite801]

I have constructed a 48v off-grid system:

- 48v Sigineer 3000w offgrid inverter/SCC/MPPT/
- 8 12v/150ah LiOP batteries (2 x 4 in series)
- 6 string Eco-Worthy combiner box
- 10- 100w/12v panels (2 x 5 in series)
- 9- 210w/12v panels (3 x 3 in series)

The system works great except that I can't get any PV input from the 210w panels. I've tested each panel individually. tested the wires and connections. i've tried different connection boxes. It seems that only the 100w panels are producing (average 750w). The max potential of the system is 2,880w.

I have an extra 4 string Eco-Worthy combiner box and a Victron 150/30 MPPT and I attempted to hooked the 210w panels to the Victron and leave the 100w panels on the Sigineer and connect the PV Outputs from each to the batteries using 2 bus bars.

What I uncovered was almost max Volts but 0 Amps (ergo 0 Watts). In troubleshooting, it said that the MPPT was not connected to or reading the batteries, but it was showing the same voltage as my stand alone battery meter so it must be connected. It also said the Volts with no Amps means "Open Circuit", but how can that be?!?!

The Victron is grounded. The 3 3 x 210w panels are hooked up correctly. I also tried hooking different wires to different sets of panels, hooking different panels together, swapping from 3 strings of 3 to 1 string to 2 strings. I also tried 2 panels hooked in parallel and the voltage dropped in half but still no Watts.

No fuses are blown otherwise the 2 5 x100w wouldnt be working.

Side note: last week when I 1st set up the system and had only 2 5 x100w and 2 3 x 210w I did register 1,600w PV input during ideal conditions which I believe was the result of the 2 100w strings and 1 of the 2 210w strings working at almost max. Also, at times, the new string of 3 x 210w seems to actually make the PV input Watts drop when plugged.

Please help!!

Are all the panels wired along the same polarity? You have to check each panel with everything disconnected to make sure which wire is positive and which is negative, because I've seen where panels had the wrong male/female MC4 ends on them.

Aside from simple checking Voc with a voltmeter, a quick and dirty test on a panel or on an array (to check Isc performance under load), is to put some temporary pigtails on and short the + and - together while having an amp-clamp meter on the wire and volts will drop to zero, where it will pull full amps. Please note that it can or will arc (with higher voltages) when you disconnect the short, so be careful with high voltages, and pull the wires far apart abruptly upon disconnect (so it can't maintain an ongoing arc).

I would check each panel individually, then all together in sections, and then check as a whole to help isolate where the problem is at in the circuit.

 

[Zwy]

I have constructed a 48v off-grid system:

- 48v Sigineer 3000w offgrid inverter/SCC/MPPT/
- 8 12v/150ah LiOP batteries (2 x 4 in series)
- 6 string Eco-Worthy combiner box
- 10- 100w/12v panels (2 x 5 in series)
- 9- 210w/12v panels (3 x 3 in series)

The system works great except that I can't get any PV input from the 210w panels. I've tested each panel individually. tested the wires and connections. i've tried different connection boxes. It seems that only the 100w panels are producing (average 750w). The max potential of the system is 2,880w.

I have an extra 4 string Eco-Worthy combiner box and a Victron 150/30 MPPT and I attempted to hooked the 210w panels to the Victron and leave the 100w panels on the Sigineer and connect the PV Outputs from each to the batteries using 2 bus bars.

What I uncovered was almost max Volts but 0 Amps (ergo 0 Watts). In troubleshooting, it said that the MPPT was not connected to or reading the batteries, but it was showing the same voltage as my stand alone battery meter so it must be connected. It also said the Volts with no Amps means "Open Circuit", but how can that be?!?!

The Victron is grounded. The 3 3 x 210w panels are hooked up correctly. I also tried hooking different wires to different sets of panels, hooking different panels together, swapping from 3 strings of 3 to 1 string to 2 strings. I also tried 2 panels hooked in parallel and the voltage dropped in half but still no Watts.

No fuses are blown otherwise the 2 5 x100w wouldnt be working.

Side note: last week when I 1st set up the system and had only 2 5 x100w and 2 3 x 210w I did register 1,600w PV input during ideal conditions which I believe was the result of the 2 100w strings and 1 of the 2 210w strings working at almost max. Also, at times, the new string of 3 x 210w seems to actually make the PV input Watts drop when plugged.

Please help!!

Always check the polarity of each panel when installing.

The ? at the factory doesn't always get it labeled correctly.

 

[BulldawgSolar]

Please provide PV panel specifications

Please clarify:
2 x 5 in series means 5 panels in series, two sets of 5 in parallel, i.e., 5S2P?
3 x 3 in series means 3S3P?
You have these two arrays in parallel with each other into the same MPPT?

I have 2 strings of 5 100W, 12v panels in series and 3 strings of 3 210w, 12v panels in series.

I have tried hooking all 5 strings to the same MPPT and the 2 5 x 100w in one and the 3 x 210w in a separate MPPT

 

[BulldawgSolar]

Please provide PV panel specifications

Please clarify:
2 x 5 in series means 5 panels in series, two sets of 5 in parallel, i.e., 5S2P?
3 x 3 in series means 3S3P?
You have these two arrays in parallel with each other into the same MPPT?

To clarify, all 5 strings of panels in series are hooked directly to the combined box, not to each other in parallel and then to the box. Did that make sense?

 

[BulldawgSolar]

Always check the polarity of each panel when installing.

The ? at the factory doesn't always get it labeled correctly.

Wow! So even though the panels all have the the right side wire (when viewed from the back) labeled as (+) and had a male connector it may not actually be the POSITIVE lead?!?

 

[BulldawgSolar]

Please provide PV panel specifications

Please clarify:
2 x 5 in series means 5 panels in series, two sets of 5 in parallel, i.e., 5S2P?
3 x 3 in series means 3S3P?
You have these two arrays in parallel with each other into the same MPPT?

Please provide PV panel specifications

Please clarify:
2 x 5 in series means 5 panels in series, two sets of 5 in parallel, i.e., 5S2P?
3 x 3 in series means 3S3P?
You have these two arrays in parallel with each other into the same MPPT?

Is this enough info?

 

[sunshine_eggo]

5S2P 100W = 94.5Vmp

3S3P 210W = 50.31Vmp

The 3S3P 210W array voltage is too low to charge your 48V battery.

Those two arrays must not be paralleled to the same controller. Their Vmp is way off. The 210W panels will force the 100W panels to operate at about 66V, which is suboptimal. The 210W panels will likely produce nothing, and they will limit the 100W panels to no more than about 800W in perfect conditions.

You need to reconfigure the 210W panels as 4S2P (yes, discard the 9th panel) and connect them to a separate charge controller.

 

[OzSolar]

5S2P 100W = 94.5Vmp

3S3P 210W = 50.31Vmp

The 3S3P 210W array voltage is too low to charge your 48V battery.

Those two arrays must not be paralleled to the same controller. Their Vmp is way off. The 210W panels will force the 100W panels to operate at about 66V, which is suboptimal. The 210W panels will likely produce nothing, and they will limit the 100W panels to no more than about 800W in perfect conditions.

You need to reconfigure the 210W panels as 4S2P (yes, discard the 9th panel) and connect them to a separate charge controller.

Nice work!

 

[BulldawgSolar]

5S2P 100W = 94.5Vmp

3S3P 210W = 50.31Vmp

The 3S3P 210W array voltage is too low to charge your 48V battery.

Those two arrays must not be paralleled to the same controller. Their Vmp is way off. The 210W panels will force the 100W panels to operate at about 66V, which is suboptimal. The 210W panels will likely produce nothing, and they will limit the 100W panels to no more than about 800W in perfect conditions.

You need to reconfigure the 210W panels as 4S2P (yes, discard the 9th panel) and connect them to a separate charge controller.

Thank you so much! All of you!

I think this is starting to sink.

If I'm right, you are suggesting the 2 x 5S2P 100W panels resulting in 94.5v/10.6a connected to the Victron SSC/MPPT 150/35

AND

the 2 X 4S2P 210W panels resulting in 67.98v/24.96a connected to the Sigineer 48v 3KW SSC/MPPT/INVERTER.

Both would be well within the operating Max/Min Volts & Amps of each, right?

Lastly, I hope... to achieve the 2P part of 5S2P and 4S2P, do I use Y-connectors to combine the 2(+) and 2(-) of each string and use just 1 set of the 6-String Combiner Box for the 4S2P(210) and the same for the 5S2P(100) connecting to 1 set of the 4-String Combiner Box?

Or does the Combiner Boxes make each connection a parallel connection when plugged directly into the boxes? Silly, I know.

Nice work!

 

[Zwy]

Wow! So even though the panels all have the the right side wire (when viewed from the back) labeled as (+) and had a male connector it may not actually be the POSITIVE lead?!?

Yes, always check polarity.

 

[curiouscarbon]

Wow! So even though the panels all have the the right side wire (when viewed from the back) labeled as (+) and had a male connector it may not actually be the POSITIVE lead?!?

yes, it is surprising to me too. i used to assume the person or people assembling a device for sale would check and confirm correct connection polarity, as it is a very basic safety check for harm reduction.

however, more than one solar panel i have used has had incorrectly labeled polarity and or incorrect polarity connector. conventions conventions and mistakes...

one reliable way is to just put the darn thing in the sun or even under a lamp, and safely check with a multimeter.

ridiculous! this is the way to have confidence.

 

[sunshine_eggo]

Thank you so much! All of you!

I think this is starting to sink.

If I'm right, you are suggesting the 2 x 5S2P 100W panels resulting in 94.5v/10.6a connected to the Victron SSC/MPPT 150/35

AND

the 2 X 4S2P 210W panels resulting in 67.98v/24.96a connected to the Sigineer 48v 3KW SSC/MPPT/INVERTER.

Both would be well within the operating Max/Min Volts & Amps of each, right?

Yes.

Lastly, I hope... to achieve the 2P part of 5S2P and 4S2P, do I use Y-connectors to combine the 2(+) and 2(-) of each string and use just 1 set of the 6-String Combiner Box for the 4S2P(210) and the same for the 5S2P(100) connecting to 1 set of the 4-String Combiner Box?

Or does the Combiner Boxes make each connection a parallel connection when plugged directly into the boxes? Silly, I know.

Depends on your combiner box. Combiner boxes generally take the input strings and parallel them into 1 or more outputs. I have a 6-1 combiner box. 6 inputs, 1 output. It parallels six strings of panels to one MPPT. Some combiner boxes have multiple outputs.

With 2P, you technically don't need fuses or breakers on each string (only required with 3P or higher). You could opt to use parallel branch connectors and then go straight to the MPPT. No fuses or breakers. If you want one, there are MC4 fuses. You can put a single one at any point in the string.

It hasn't been mentioned, but I think it may have occurred at some point in your testing depending on your combiner box. Never share arrays between MPPTs. They'll fight over the array, and your performance will stink.

 

[BulldawgSolar]

Yes.



Depends on your combiner box. Combiner boxes generally take the input strings and parallel them into 1 or more outputs. I have a 6-1 combiner box. 6 inputs, 1 output. It parallels six strings of panels to one MPPT. Some combiner boxes have multiple outputs.

With 2P, you technically don't need fuses or breakers on each string (only required with 3P or higher). You could opt to use parallel branch connectors and then go straight to the MPPT. No fuses or breakers. If you want one, there are MC4 fuses. You can put a single one at any point in the string.

It hasn't been mentioned, but I think it may have occurred at some point in your testing depending on your combiner box. Never share arrays between MPPTs. They'll fight over the array, and your performance will stink.

Excellent! I'll check all of the fuses and use a 4-String Combiner Box and Victron MPPT for the 5S2P 100W and the 6-String Combiner Box and Sigineer for the 4S2P 210W.

Hopefully I get some clear skies today and real report back.

 

[BulldawgSolar]

Excellent! I'll check all of the fuses and use a 4-String Combiner Box and Victron MPPT for the 5S2P 100W and the 6-String Combiner Box and Sigineer for the 4S2P 210W.

Hopefully I get some clear skies today and real report back.

Yes.



Depends on your combiner box. Combiner boxes generally take the input strings and parallel them into 1 or more outputs. I have a 6-1 combiner box. 6 inputs, 1 output. It parallels six strings of panels to one MPPT. Some combiner boxes have multiple outputs.

With 2P, you technically don't need fuses or breakers on each string (only required with 3P or higher). You could opt to use parallel branch connectors and then go straight to the MPPT. No fuses or breakers. If you want one, there are MC4 fuses. You can put a single one at any point in the string.

It hasn't been mentioned, but I think it may have occurred at some point in your testing depending on your combiner box. Never share arrays between MPPTs. They'll fight over the array, and your performance will stink.

It worked!!! Changed up the 9 210w 3S3P to 8 210w 4S2P going to a separate MPPT and it "seems" to be working well!

My 2 x 4-12V/150ah LiOP battery banks quickly charged up to 58v, I turned on the AC and lights 1.5 hrs ago and my batteries have stayed above 51v!!

I had a high temperature auto stop on the Sigineer but fixed that with a fan.

When the clouds stayed away, I'm getting 1,450-1,500w from the 8 210w panels and 850-920w from the 10- 100w panels!!

The max draw has been 2.2kw and the panels alone were powering the AC needed while charging the batteries!


I am SO PUMPED!

I really can't thank this forum enough!!

I AM FULLY OFF-GRID WITH AIR CONDITIONING!!!!!??????

 

[BulldawgSolar]

Next question!! Lol! Thoughts on Over-Paneling? Is it a good idea?

If so, I have an extra 100W, 12v panel and an extra 200w, 12v panel. What would be the best way to do it?

It appears that my basic AC output need is 2.2kw and my current panels are providing 2.3kw in good, not perfect, conditions. With a 48v, 3kw inverter, would it be advisable to buy 4 x 100w/18.9v VMP/5.3a IMP) panels for a 3rd string making 5S3P(500w x 3)

OR

3 more 210W(16.77v VOC/12.48a IMP) panels making a 3rd string for 4S3P (+830w x 3)

 

[sunshine_eggo]

If you're getting 70-80% of rated in decent solar conditions, that's pretty much a win.

Glad to hear it's sorted!

When you have to mix panels on the same MPPT:

Parallel Vmp-Voc range should be very similar - within 10%
Series Imp-Isc values should be as close as possible. All panels in series will operate at the LOWEST rated current.

 

[BulldawgSolar]

Actually, I should have asked if Over-Panelling by adding a 3 string of 100W to make 5S3P is advisable. Adding the 210W panels would be too close to max amperage for that controller

 

[sunshine_eggo]

Victron is very clear in their overpaneling criteria:

1) Never exceed Voc input limit.
2) Never exceed PV input current limit.

#1 needs a little head room for cold weather voltage increases, but you can run the amps right up to the limit.

This process is generally true for most MPPT even if it's not published. If MPPT place hard limits on the input, respect them.