diy solar

diy solar

Swapped out suitcase panel, copied wiring = solar overvoltage error?

+1
What is the spec of the SCC max PV input Voltage?

Based on the stciker of the old dual-panel,
Each panel should have
Voc of 10.60V (21.20 Voc divided by 2).
Vmp of 8.85V (17.70V divided by 2).
Imp of 11.30A.

Youe new 100W panel has
Voc of 21.20V.
Vmp of 17.7V.
Imp of 5.70A.

So when you connect one of the old panel in series with the new panel.
The system parameters are:
Voc of 10.60V + 21.20V = 31.80V
Vmp of 8.85V + 17.70V = 26.55V
Imp for series connected panels will be equal to the lowest Imp rating of the panel = 5.70A
So the system panel power will be = 26.55V * 5.70A = 151W.
The panel specifications are correct, with a OC voltage of 21v. You have wired is series thus giving an over voltage fault indication, The PWM charge controller you have is specified for a maximum input voltage of 26 volts.


Reconnect the panels in parallel. Make sure you have a voltmeter of some type to ensure you get the polarity correct. Connect the battery first to the controller, then the panels.

Mike

Sorry 'resident asshat' typing as you posted.


So if the voltage is in fact different on the two panels I now have (half of the old set + the new one) (which seems likely), can I still wire them together in parallel?

And if so, would I need to do anything different than following the basic instructions I find online (using y-splitters)?

My "I'll just get a replacement and make sure I wire it the same" project has now officially turned into "a learning experience" ?
 
To your point, it would be hard to wire them in parallel if they were originally in series. A 2 into 1 connector would be required. Unless you have spare parts sitting around, it's unlikely it was wired in parallel originally.
I don't mean to be dense here, but I posted a pic of the old system's wiring and my wiring on the new combo, and they are exactly the same.

How could it have been 'invisibly' wired in parallel before in such a way that it looks the same as what I did (series), yet somehow functions in parallel?
 
So if the voltage is in fact different on the two panels I now have (half of the old set + the new one) (which seems likely), can I still wire them together in parallel?

And if so, would I need to do anything different than following the basic instructions I find online (using y-splitters)?

My "I'll just get a replacement and make sure I wire it the same" project has now officially turned into "a learning experience" ?
I could look in the panel boxes of my 100 watt suitcase that is 2 50w wired parallel to see how they did it.
These suitcases do Not need Y splitters.

Also do you have a multimeter with you as that would end your confusion.
 
Last edited:
I don't mean to be dense here, but I posted a pic of the old system's wiring and my wiring on the new combo, and they are exactly the same.

How could it have been 'invisibly' wired in parallel before in such a way that it looks the same as what I did (series), yet somehow functions in parallel?

That's what I'm saying. You didn't change the wiring. The new panel isn't really the same as the old panel.

Edit for clarification: The sticker that was posted for the old "panel". Is that for each panel, or for both panels together? There is something out of kilter here.
 
Having looked at the photo in the Renogy add it does seem that the panels are wired in series. This is from the add,
renogy panels.jpg
The early post suggesting the panels were actually 'half' panels may be correct.

With the normal panels of 32 cells they are arranged in groups of 16 with bypass diode, connected in series inside the junction box to give a nominal 18 volts or so under load. I suspect the two 'halves' have been rewired by Renogy in parallel giving a 9 volt output.

A picture on the connections inside each junction box would be useful.

Mike
 
Last edited:
Another thing to support my hypothesis....
Take off the box cover on the old panel and post a photo of the wiring........thanks........
OK, here are my new and old panel's wiring. There are def different.

Can you tell me what this means? I don't have any idea what I'm looking at.

Can these be wired together, even in parallel?
 

Attachments

  • 20210303_112712.jpg
    20210303_112712.jpg
    49.5 KB · Views: 15
  • 20210303_112650.jpg
    20210303_112650.jpg
    35.8 KB · Views: 16
This post has gone over the edge.
THE 2 PANELS ORIGINALLY WERE WIRED IN PARALLEL as it is impossible to be in Series with that low max voltage PWM scc.

The replacement panel is almost identical to the old panel.

I could look in the panel boxes of my 100 watt suitcase that is 2 50w wired parallel to see how they did it.
These suitcases do Not need Y splitters.
You changed the wiring.
You should have taken pics of the inside wiring in the boxes.

Also do you have a multimeter with you as that would end your confusion.
I don't have a multimeter with me and I'm currently in the Anza Borrego desert so there isn't a place to pick one up cheaply anywhere nearby.

I'll either pick another one up when I'm back in town, or I have a friend visiting in a couple of weeks who can bring me my tools from home.
 
Having looked at the photo in the Renogy add it does seem that the panels are wired in series. This is from the add,
View attachment 39388
The early post suggesting the panels were actually 'half' panels may be correct.

With the normal panels of 32 cells they are arranged in groups of 16 with bypass diode, connected in series inside the junction box to give a nominal 18 volts or so under load. I suspect the two 'halves' have been rewired by Renogy in parallel giving a 9 volt output. This could be done easily inside the junction box.

A picture on the connections inside each junction box would be useful,

Mike
+1, the old panels are wired in series as shown in the OP pictures in post #1, you can see positive lead of one panel connected to the negative lead of the other panel.
Once OP get the meter then OP can easily check the Voltage of each panel.
 
Having looked at the photo in the Renogy add it does seem that the panels are wired in series. This is from the add,
View attachment 39388
The early post suggesting the panels were actually 'half' panels may be correct.

With the normal panels of 32 cells they are arranged in groups of 16 with bypass diode, connected in series inside the junction box to give a nominal 18 volts or so under load. I suspect the two 'halves' have been rewired by Renogy in parallel giving a 9 volt output. This could be done easily inside the junction box.

A picture on the connections inside each junction box would be useful,

Mike
Junction boxes are def different. I posted these in response to someone else, too. I'm not sure how notifications get sent so sorry for the double post.

Do I have two solar panels here that will never work together, regardless of wiring?
 

Attachments

  • 20210303_112712.jpg
    20210303_112712.jpg
    49.5 KB · Views: 2
  • 20210303_112650.jpg
    20210303_112650.jpg
    35.8 KB · Views: 2
I am not guessing.
Its a simple problem.
All these suitcases are wired in parallel to work with a ~ 26Voc Max PWM scc.
2 in 21Voc panels in series is 42V which trips the overvoltage error.
Please show us the parallel wiring on the old setup.
20210302_174037-jpg.39291
 
From the front they look exactly the same
Ok I have to look at what my 100watt suitcase outputs off the 2 50w panels but it is raining right now.
I was going to change the PWM to a MPPT so I can charge a LFP battery.
 
You could just use the new panel on its own for now.

The new panel is defiantly two 16 cell groups in series, the old panel has, I suspect, the cell groups in parallel giving a '6 volt' panel with the connections within the panel.

The labels on the panels are defiantly misleading.

Mike
 
You could just use the new panel on its own for now.

The new panel is defiantly two 16 cell groups in series, the old panel has, I suspect, the cell groups in parallel giving a '6 volt' panel with the connections within the panel.

The labels on the panels are defiantly misleading.

Mike
Thanks.

I will def work on re-wiring to just use the new one. That seems simple enough ??
 
Thanks.

I will def work on re-wiring to just use the new one. That seems simple enough ??
The question now is if you can buy 100w replacement panels for that suitcase.
Good luck with Renogy customer service.
 
The question now is if you can buy 100w replacement panels for that suitcase.
Good luck with Renogy customer service.
Yeahhhh I already submitted a warranty claim because the cause of the panel breaking was, functionally, both of the leg stands breaking. I sent an email follow up at ten days, but still have heard nothing.

Their "famous" customer service is why I was trying to fix it myself...and on this forum. If these can't be wired together, it seems like just tossing the old stuff and starting from scratch may be the better path. Which would be a $600+ bummer but...learning experience.
 
Yeahhhh I already submitted a warranty claim because the cause of the panel breaking was, functionally, both of the leg stands breaking. I sent an email follow up at ten days, but still have heard nothing.

Their "famous" customer service is why I was trying to fix it myself...and on this forum. If these can't be wired together, it seems like just tossing the old stuff and starting from scratch may be the better path. Which would be a $600+ bummer but...learning experience.
Ok so the damaged panel is functional but has broken legs.
If under warranty they should send you a new suitcase.
 
Ok so the damaged panel is functional but has broken legs.
If under warranty they should send you a new suitcase.
No, the legs broke and it fell sideways on top of a rock and the other panel is f*cked
 

Attachments

  • 20210218_171454.jpg
    20210218_171454.jpg
    163.5 KB · Views: 7
Back
Top