Lightning strikes again? Morningstar TS 60

mcgivor

Yesterday there was a violent storm which passed through, major lightning, I was not at home so shutting down wasn't an option, but could see the storm move in from where I was 4Km to the south, was on a tractor so no chance of racing home. When I got home the smell of magic smoke filled the room where the controller, Morningstar TS 60, is located, can't say 100% if lightning was the cause but too coincidental to be anything else. The component(s) that vaporized appear th be the diode(s) nearest the solar input positive terminal, SPD didn't help and appears fine?, everything else in the system still functional, the controller was indicating over voltage shutdown, red/green Led's alternating, remote meter blank but still functional with replacement unit,  had a spare on hand, so 30 minutes to get up and running. Last time the inverter got surged and falied, ironically a year ago, May 2017.

Estragon

Struck by lightning twice in a year? Ugh! Would a lightning rod help?

westbranch

 Where is the one you have positioned in the wiring ? Do you have more than 1 SPD?

Photowhit

Estragon said:

Struck by lightning twice in a year? Ugh! Would a lightning rod help?

It might hurt! My understanding is most damage from lightning strikes are near misses that come in from the grounding of the system. Likely a direct hit would do some damage outside of the power center...

mike95490

That's a lot of smoke for a diode. Or it was a very large diode.  I'd consider it all toast.  Expect other electronics to be weakened and about to fail.  

westbranch

3 minimum showing in this document   http://www.midnitesolar.com/pdfs/classic_simple_flow_diagram.pdf

Estragon

Just as a matter of interest, are the big zig-zaggy things how the CC transfers heat to the external heat sink fins?

If so, maybe a lower resistance path to ground? Having gone miles, I'm sure lightning does what it wants, but maybe that's a tasty target. It would also avoid a SPD on the DC wiring that way?

mcgivor

SPD wise, DC, one at incoming solar disconnect, downstream side, AC, main live bus. 
Lighting rod? Do have a mast with an air terminal, was hit 4 days after installing, took out the inverter no SPD at that time.
The zigzag thing is an aluminum bar with a stainless steel spring, under which is a plastic piece with fingers that pass through the PCB appling pressure to the mosfets against the heat sink , the 3 screws thread into the heat sink.

Bad luck perhaps, the mast is intended to offer a path to ground other than a structure, dose it contribute to the damage caused, who knows, my understanding is that if lightning is going to strike in the area the point of contact is generally concluded at the last micro second so the mast offers a path of least resistance.

 

Estragon

Bad luck perhaps ...

Since you and your family are still here to tell the tale, I guess it depends how you define bad luck

Sometimes bad stuff happens to good people. It just is.

Dave Angelini

Reasoning with lightning can be as reasoning with hurricanes (cyclones) 

mcgivor

Out of curiosity I made contact with tech support including images, asking what they thought the cause of failure might be, without furnishing any details, emphasis on no warranty claim despite being within warranty. The response was. The damage to D3 is consistent  with a high voltage transient, was lightning present in the area? Naturally I answered honestly that it was likely and that I was just interested in their opinion.

Dave Angelini

Looks like it to me.... Only crazy people would give warranty for that! 
I once visited a boat that was hit and in the day all the lighting was incandescent.
Every light bulb exploded and there was glass everywhere. You can imagine what the inside of electronics looked like.
They lost 3 garmin gps units. they were over 1,500 us dollars then.

oil pan 4

Since you are running low volts maybe you could try installing an electric fence lightning arrestor on your + and - solar panel wires going to ground?

myocardia

oil pan 4 said:

Since you are running low volts maybe you could try installing an electric fence lightning arrestor on your + and - solar panel wires going to ground?

The SPD he mentioned in the OP is a surge protector device, which is what Midnight calls their lightning arresters: https://www.solar-electric.com/midnite-solar-mnspd-300-dc-surge-protector.html

oil pan 4

I saw that and it doesn't appeared to have helped much.
The electric fence lightning protectors are just a good old fashioned spark gap and they only cost a few dollars.

mike95490

By the time a " good old fashioned spark gap " triggers, the electronics are way past dead.  The midnight SPD's come in several voltage protection ranges, so you can maintain as small as possible "unprotected" voltage range.

oil pan 4

Is one of those fancy protection methods a spark gap? 
If not then wouldn't we be trying the same thing and expecting a different result? 
I believe that is the definition of insanity.

mcgivor

SPD's do not use a spark gap, there are various types which employ different semiconductors varistors, thyristors, diodes etcetera to divert unwanted harmful transients to ground.
https://www.nemasurge.org/how-spd-s-work/? 

oil pan 4

I'm well aware of varistors, I put them on all my welders and air compressors.