Replacing bypass diodes, Q-Cell G5 320 watt panels.

[CrazyWabbit]

My house got hit by lightning, I don’t see evidence of panels taking a direct hit. Seven out of fifty six panels were down the next day. Tech replaced IQ7+ inverters and that didn’t fix the system so he replaced the panels with G6’s. I kept the equipment and have dug out the silicone sealant and replaced the diodes with the same part number. Panels now work and pass OC voltage test and short circuit test. What sealant should I use?

https://www.hbfuller.com/en/north-america/products-and-technologies/brands/tonsan

I found HB Fuller 1533 sealant and can source it for about 100 bucks a tube in the US. What do y’all recommend? Does it have to be low acidic…
Repaced with new diode;


Bad diode, still encapsulated:

3/4 of the diodes unsoldered them selfs from the base. That made the work a little easier. Each panel has three diodes.

Edit: I ordered RTV11-1P

RTV11-1P MG Chemicals | Tapes, Adhesives, Materials | DigiKey

Order MG Chemicals RTV11-1P (473-1272-ND) at DigiKey. Check stock and pricing, view product specifications, and order online.

www.digikey.com

 

[svetz]

My house got hit by lightning, I don’t see evidence of panels taking a direct hit. Seven out of fifty six panels were down the next day.

Yikes!

I kept the equipment [panels] and have dug out the silicone sealant and replaced the diodes with the same part number. Panels now work and pass OC voltage test and short circuit test.

Clever!!! Nice of the diodes to go first like OC protection.

I found HB Fuller 1533 sealant and can source it for about 100 bucks a tube in the US.

Sounds expensive. Any conformal coating would work I'd think (e.g., coat the board and then any sealant over it).
Haven't tried it but perhaps someone else has tried something like https://www.amazon.com/Clear-Electronic-Grade-Silicone/dp/B07MKBBQTC?

Linking @BiduleOhm as I know he's done a lot with electronics.

 

[BiduleOhm]

What you're looking for is called potting compound and can go from rock hard epoxy resin to soft re-enterable gel

 

[CrazyWabbit]

The RTV11-1P worked wonderfully. Looks same as stock now. Came with two 1lb containers, used one. 1 pound/tin had coverage to do 14 panels I think.

Edit: The asi-388 is non slump, in other words it will not flow or self level. The rtv11-1p would work well for repairing things like ego bms boards, repair would be same as stock.

 

[yellowjeep2850]

Hey , so where can you get the diodes , and did you repair the panels i would like to have some spares just in case I have qcell 480 bfg's myself ...
I bet it was a chore digging out all the sealant for sure

 

[DThames]

Silicon sealer from the hardware store should work. The main goal is to keep out water and that is what it is made for. I am not talking caulk.

 

[Substrate]

I did that to my beloved Sanyo panel. Lets just say that I attached a battery directly to it, with polarity reversed. But don't tell anyone.

Diodes were special match-n-batch from the factory, but I just resolved to buy a 5-pack of the so-called solar-bypass diodes, and matched and batched them for forward voltage drop and picked the best 2 closest to each other.

Since it was already ugly from digging them out, I used double the original spec amperage rating bypass diodes, rather than the same rating that came with the panel. A little more surface area dissipation.

Used RTV, but what the heck, made sure it was the high-temp type.

 

[BiduleOhm]

Just a small FYI: it is not recommended to use acetic based silicone, which RTV typically is, as it's acidic and may cause damages in the long term.

 

[Shawn Hayes]

My house got hit by lightning, I don’t see evidence of panels taking a direct hit. Seven out of fifty six panels were down the next day. Tech replaced IQ7+ inverters and that didn’t fix the system so he replaced the panels with G6’s. I kept the equipment and have dug out the silicone sealant and replaced the diodes with the same part number. Panels now work and pass OC voltage test and short circuit test. What sealant should I use?

https://www.hbfuller.com/en/north-america/products-and-technologies/brands/tonsan

I found HB Fuller 1533 sealant and can source it for about 100 bucks a tube in the US. What do y’all recommend? Does it have to be low acidic…
Repaced with new diode;
View attachment 77125

Bad diode, still encapsulated:
View attachment 77126
3/4 of the diodes unsoldered them selfs from the base. That made the work a little easier. Each panel has three diodes.

Edit: I ordered RTV11-1P

RTV11-1P MG Chemicals | Tapes, Adhesives, Materials | DigiKey

Order MG Chemicals RTV11-1P (473-1272-ND) at DigiKey. Check stock and pricing, view product specifications, and order online.

www.digikey.com

Where did you find your replacement diodes?
Looking to have spares just in case....
I have the G-5 330W panels.

Also, any advice or instructional information on how you replaced the diode, the process, and reconnecting wires/cable etc..
Just trying to get ahead/prepared in case repairs are needed in the future.
Thanks.