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Refrigerator ground wire to solar controller

rbflapjack

Active member
My Renogy solar controller went blank and while troubleshooting (with great help from Steve from Alliance) I found that Alliance connected the negative wire from the fridge to the panel-negative terminal of the solar controller. Everything was working fine until the controller went out but I'm wondering if this contributed to the controller failure. I'm guessing that the panel negative is grounded so where but I haven't found it yet.

1. When I get the new controller, should I wire it as before with the refrigerator ground wire going into the controller or could this be doing damage?

2. If I change the wiring, do I just leave the panel negative wire grounded wherever it may be and then ground the refrigerator wire and ground the negative side of the panel voltage on the controller?

3. Otherwise, to wire it correctly, I would need to find where the panel voltage wire is grounded and does anyone have any ideas where that might be so I can remove it and wire it to the controller? I assume then I would just ground the refrigerator correct?

Sorry for the convoluted post but this thing has been giving me fits for days now but again thanks to Steve for his patience.
 

rbflapjack

Active member
got a picture with some call outs on which wire is which?
I don't but will try tomorrow but not sure what it will show. All I can see is the black 8awg wire that is connected to the PV side of the solar controller. I naturally assumed this went to the negative side of the panel but a continuity test showed that this to be incorrect. When I disconnected this wire from the controller, the fridge stopped working. Steve at Alliance mentioned that he has seen a few issues where the assembly line crossed wires and wired the black wire from the fridge to the controller which is what happened in my case. I haven't found the end of the panel black wire but will keep looking. Since the controller has been working for more than a year, I'm guessing this wire is grounded somewhere.
 

Oregon_Camper

Forum Admin
Staff member
Assuming these 2 connections were crossed? They would share a NEG busbar connection (inside the unit), so I guess it would work as long as the "LOAD-" was connected to ground.

1750993200624.png
 

rbflapjack

Active member
Assuming these 2 connections were crossed? They would share a NEG busbar connection (inside the unit), so I guess it would work as long as the "LOAD-" was connected to ground.

View attachment 3658
Nothing is crossed at the controller itself. All the wires going into the controller look like they are correct on the outside. The red PV wire into the positive PV post and so on. The issue is that the black wire that is labeled PV negative and connected to the PV negative post on the controller isnt actually the panel PV negative wire but is the negative side of the refrigerator. At the factory, when they ran the wires from the panel and the refrigerator, they got them crossed and labeled the refrigerator ground wire as PV negative and then connected it to the PV- post on the controller. That's why I'm not sure a picture will do any good because it will show all the wires connected correctly at the controller. The actual negative wire from the panel is grounded somewhere but I haven't found it yet.
 

rbflapjack

Active member
Assuming these 2 connections were crossed? They would share a NEG busbar connection (inside the unit), so I guess it would work as long as the "LOAD-" was connected to ground.

View attachment 3658
But reading your post again does help me quite a bit. If there is a negative bus bar inside the controller unit, does that connect the PV negative, battery negative, and load negative all together? That would make sense why the miswiring worked. The battery negative is connected to the negative side of the battery which is also connected to ground so if all three negative posts are on one bus bar then they are all grounded together.
 

Oregon_Camper

Forum Admin
Staff member
If there is a negative bus bar inside the controller unit, does that connect the PV negative, battery negative, and load negative all together?
Yes...the would be connected inside the controller. Now that you know which wire is the frig's NEG cable cable...move it away from Renogy controller to a proper ground terminal, that directly connect to ground. Then use the other cable for the controller ground.
 

rbflapjack

Active member
Yes...the would be connected inside the controller. Now that you know which wire is the frig's NEG cable cable...move it away from Renogy controller to a proper ground terminal, that directly connect to ground. Then use the other cable for the controller ground.
Thanks, now I just have to find where they grounded the PV black wire.
 

rbflapjack

Active member
Thanks, now I just have to find where they grounded the PV black wire.
Problem solved! Indeed I found that the factory had wired it incorrectly. When they pulled the ground wire from the refrigerator and the ground wire from the panel they got them swapped in the basement since they are both black 8 gauge wires. They ended up grounding the negative wire from the panel and connecting the ground wire of the refrigerator into the charge controller. I was able to trace it down and swap them back and wire it correctly. I did have to replace the charge controller and replaced it with a victron which hopefully will last longer than the renogy.
 
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