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Stan Flowers avatar image

Accidentally reversed polarity of pv input

Mppt 150/100 appears to be blown due to reversed pv input polarity. Is it possible to repair the damaged unit from this type of fault?

MPPT - Solar Charge Controller
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@Stan Flowers I have seen reverse polarity made on an mppt from the pv side with the battery connected correctly. It had been like that for several hours. All that happened was the unit heated up. Once the mistake was corrected it was fine and functions as if nothing happened. This is how the manual describes what happens.

If the battery was reversed and pv connected there is a fuse internally that blows at minimum.

Both of these secenarios void warranty.

Opening the unit does damage components if not done carefully as they are bonded inside. But can be done if a person has the patience and skill for it.

Have you tried a firmware update? Or tried accessing the info off the unit? If it is not communicating then it may not be worth fixing.


2 Answers
EricK1974 avatar image

Sadly same happened to me, one string was reversed and although it should be reversed polarity protected was blown. The MPTT which is integrated in the easysolar 1600 unit this happende on has 3 PV inputs, the other inputs seem to be working. Is it correct to assume the 3 inputs are separated and separately fused internally? As I have no monitor (BMV7xx) I cannot see the the levels but I do see the bulk led on with the other PV inputs correctly connected. Is there an easy way to be sure it still works?


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HI @EricK1974 you can check if your battery is charging using a multimeter or a DC clamp meter

Stefanie avatar image

AFAIK all Victron MPPT's are protected against the reverse polarity on the input.
Maybe you can describe a bit more precise what happened and what makes you believe that it doesn't work anymore.

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Hi Stefanie,

I was getting zero output to battery, float light on permanently , PV not visible on CCGX, checked all cabling to CCGX OK. It is possible that the pv array was connected to the input incorrectly and so I returned it to service centre who tested it saying it was blown due to reverse polarity and not reparable. On the test report form it was stated reversed polarity fault - outside of warranty terms.

I see and must admit that I'm probably out of ideas in your case then.
In the product description and manual for the 150/100 it clearly says PV reverse polarity protection. The output to the battery of course is not protected against reverse polarity.

Maybe someone from the Victron official stuff is going to chime in here and can explain further.