Solar controller blowing

[Fontie]

I am currently on my third Solar controller which has just stopped working. Company that fitted lithium B2B and the controller has been very good but now this third one has gone need to look for a reason why they are going, the controller is wired solar panel to controller and out to the 2 lithium's. Could the solar panel be faulty in some way and be causing the controller to die. I havent yet told the company that fitted that its gone again.

 

[Lenny HB]

What controller is it?

 

[Fontie]

Two of these NDS 320W Sun Control 2 Dual Regulator MPPT and the one that's just gone as well NDS 350W Sun Control 2 Dual Regulator MPPT. Its a Auto-Sleeper 80w panel that came with the van. All three cant all be duff controllers.

 

[Richard n Ann]

Send it the you tuber Big Clive for it's dissection and our viewing pleasure

 

[Raul]

Killer no 1 for a controller is over voltage in, second, reverse polarity or short.

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[PhilandMena]

Killer no 1 for a controller is over voltage in, second, reverse polarity or short.

I thought most if not all controllers had protection against these types of faults.

 

[DBK]

Those controllers have a maximum input voltage of just 29.5 volts so hopefully if you have more than one panel they are wired in parallel. It would be worth checking the input voltage on a sunny day.

 

[Phill D]

The nds mppt has an internal spade fuse is it just that has fused?

 

[Fontie]

I have one 80w panel. The only common dominator is all 3 have gone when its been hot so the panel would have been hot

 

[Fontie]

Last one that went the company took it apart looked like a fet had gone with some staining on the circuit board where a group of capacitors are. I'd rather the company that fitted it takes the back of to check the fuse. I suspect its died the same way as the last one, but the cause

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[Raul]

I thought most if not all controllers had protection against these types of faults.

No controller has over voltage protection, that’s max vdc in, or voc voltage open circuit. Same goes for grid inverters, in the cold morning if the string is at limit, it can burn the dc side.

 

[tonyidle]

No controller has over voltage protection, that’s max vdc in, or voc voltage open circuit. Same goes for grid inverters, in the cold morning if the string is at limit, it can burn the dc side.

The Schaudt MPPT one does. I connected it to the wrong panel and it said "Voltage high".

 

[DBK]

The Schaudt MPPT one does. I connected it to the wrong panel and it said "Voltage high".

A warning is different to protection.

 

[Fontie]

So are we saying my panel could have put to much voltage into the controller and blown it.

 

[Raul]

What’s the spec of your panel? Can’t see a 80w having a voc higher than 30v.

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[Raul]

The Schaudt MPPT one does. I connected it to the wrong panel and it said "Voltage high".

I doubt it. You were lucky. If you look in the spec, it has a max vdc in. Even victron does not have that. A 150vdc controller can tolerate 152voc. If the voc is considerably higher in a cold morning it will burn out.

 

[Fontie]

What’s the spec of your panel? Can’t see a 80w having a voc higher than 30v.

Its a bog standard Auto-Sleeper 80w panel that they fit

 

[Pausim]

You also had a B2B fitted. When your solar controllers blow are you stationary or is the engine running? When I first installed my B2B wrongly in my previous motorhome (didn’t disable the split charge relay) I got some very strange voltages and a puff of smoke from an inverter when I shut the engine down. There was a strange surge which I never understood but think it must have been an interaction between 2 separate electronic devices that should have been separated.

 

[Fontie]

The first solar controller blew after driving back home after having everything fitted, the second lasted 5 months and this third one 6 days . With the second controller we drove to Cornwall and back home 400 odd miles and another trip to Devon 250 odd miles with it working well being off grid for a week in Cornwall and 2 weeks in Devon. There's no common theme I can put my finger on, yep it happens when.....

 

[tonyidle]

A warning is different to protection.

True but no damage ensued. A message is better than spitting blue lights.

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