Smart Solar 150/100 Burnt negetive terminal

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bigbrovar asked Feb 12, '22

Smart Solar 150/100 Burnt negetive terminal

Hi all,

I recently noticed that the negative terminal (On the PV side) of my Smart MPPT Solar charge controller 150v/100A burned out (most likely because of bad wire connection) I noticed the burn out started from the wiring (The wires were partially burnt and corroded).

I noticed this when I was moving between houses, I did not notice any drop in harvest or productivity (I would easily notice a drop in productivity since I have actively monitor my solar production on a daily and I have realtime logs extracted every 10sec and stored.

The system is 24v with 3000w panels. The system is grid interactive and a such the grid comes up at night while solar works during the day. On an average, the system peaks at about 70 to 80A / 24v during charge cycles and that has not changed.

My concern though is that the charge efficiency of the controller has been compromised due to the burnt out terminal. I have no doubt that it has introduced resistance to the charging process which I believe would only get worse.

I have since ordered for a replacement and the plan is to have this relegated for secondary use.

My question is this. Can this unit be repaired? Is the terminal replaceable? This is a very expensive device and it would be a shame to condemn it totally because of a burnt out terminal.

I purchased the device from an authorized victron deal in my country so I am hoping that they might be able to fix it back as new.

I have attached the picture of the terminal

MPPT Controllers terminals

img-20220212-101357-166.jpg (134.2 KiB)

img-20220212-101353-916.jpg (151.7 KiB)

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Alexandra answered · Feb 12, 2022 at 05:01 PM

@bigbrovar

Yes. Basically you would need to clean it. By far not the worst I have seen. Housing not too compromised. My only concern would be the part you cannot see (solder to the circuit board). Unfortunately it is a destructive process to open the 150s. But to be honest it was not hot enough to damage the plastic so it may be ok?

You can try clean the terminal with some electrical contact/switch cleaner and maybe those little stiff nylon brushes you can buy for contact cleaning.

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Answer 1 · 2022-02-14T06:15:48Z

bigbrovar answered · Feb 14, 2022 at 06:15 AM

Thanks for the response @Alexandra I guess my concern is that the burnt out negative terminal would introduce some resistance to the MPPT process (Since it is on the PV Side) handling over 27A @ 90v. I am a total noob at this (so excuse if this is just my ignorance talking)

I could use sand paper to help file the terminal and use electronic cleaner as suggested.

Is there a way to check if performance was impacted / would be impacted down the road?

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kevgermany ♦♦ commented · Feb 14, 2022 at 07:17 AM

If performance was affected, you would see it in the data.

Another option for cleaning is a hard pencil eraser, not the plastic ones. But will be difficult to get in with that. If you want to use sandpaper,ddisposable nail Giles work and can be cut to go in the slot.

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Alexandra ♦ commented · Feb 14, 2022 at 11:20 AM

As long as the corrosion/ burns are gone and there is good contact -the terminal can be tightened correctly then it should be fine.

When you do connect it again and it is working at full capacity just keep an eye on the Terminal temperature. If nothing is unusual then it should be fine.

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