Solar Panels And Lightning Protection

[linnupesa]

About 8 months ago I installed two 130W PV panels on the railings. All worked fine until recently when I returned to find the house bank discharged to almost zero volt. The charge controller had gone bad too but I found nothing smoked. I replaced it with a good unit and then found the wind generator diode was also shorted, discharging all power into the wind generator armature which was running hot by now. The wind generator had been tied off to prevent turning but was not fully disconnected from the electronics. All in all, the depth sounder, SSB, wind instruments and autopilot also were affected to various degrees, even though all the breakers had been left open.

Puzzled, I have now separately grounded the case of the charge controller. I'd believed the negative of the 12V dc bus was already an adequate ground, but now question that assumption. The boat has been in lightning-prone waters for 20-odd years unharmed, but now with 8 month of the panels on.. hmm, this may not be all just the "luck of the draw".

I've wondered if the large surface areas of the panels perhaps act as an especially good charge attraction for capacitive coupling to a near-by charge build-up, not even necessarily a direct zap. Just per chance, the radiator of the mast-head 5/8th wave VHF also went missing at the same time. It may have been just that the osprey decided to do some preening with his beak or perhaps it vibrated loose. There was just a hole left where the steel whip should have been. The base and co-ax line still seem to work fine. Coincidence too?

Alternately, going the other way, the wind generator may have gotten the diode blown and the same surge also affected the charge controller and other equipment. The radar and it's dome however, sitting right next to the also defective antenna tuner was and still is working fine though.

Any engineering thoughts and comments on this? Would it be best to disconnect the back stay antenna from the electronic antenna tuner while in port or not in use? Ground the aluminum solar panel frames themselves to the steel railings, which are (?) hopefully at boat ground? Hang a grounding fish or rod overboard while away from the installation? ( I've actually got two zincs connected to the engine hanging overboard port and starboard )

It's quite an annoying if not expensive problem and it seems to happen quite frequently even to the best of people. On a friend's boat it took out a fancy autopilot/GPS system and it would be nice to know if spark gaps or similar things might help in this situation. The electronic trans-zorbs and similar devices are supposedly the way to suppress RF transients. Perhaps ferrite chokes on the solar connections? How have your installations fared in FL? Does someone have direct experience or data on any such fixes?

Any advice or hints will be greatly appreciated.

Ivo KI6S

PS: Does anyone still have B&G Hecta/Hornet depth sounder/wind instrumentation parts or units from the mid-80's? I've got some life back into them but still no good readouts. I suspect ROM or RAM may have been corrupted but any defunct boards etc. would be welcome at a reasonable cost.

[redbopeep]

And I thought our electrical issues were bad! So sorry that I cannot help, only give you a "good luck" in the future with all and hope some good soul comes along shortly to assist with salient insights.

[MMNETSEA]

Linupesa.

Your non functioning electronic and electric equipment appear to have been hit by a "Proximity" lightning strike. In the lightning belts around the world this type of non direct hit is common. Doubt that your solar panels had anything to do with attracting the strike.

If you like I can put you in touch with friends who suffered this type - they also had B & G instruments.

[JeanneP]

It sounds as if you had a hit on your VHF antenna. We saw lightning hit ours, and it vaporized. And we lost all our electronics. We had solar panels, but that was not the problem. Here's the log of it: Watermelon log, lightning strike

Here's a link to a discussion of lightning on this board: Lightning

[magwas]

I would think that standing rigging and antennae are more attractive to lightning than solar panel, due to an effect of which I do not know the English name. It is "apex effect" in mirror translation.

[linnupesa]

Thank you all for the replies. I'll reply collectively in one mail:

Yes, I'd like to share the B&G problems more specifically... perhaps there are some manufacturer specific issues that need to be addressed. Especially as the mfr's do not like to share such info publicly or pooh-pooh the cures. ( Like with BP's oil pussyfooting or Apple's "You do not hold the phone right" hello??? )

I like the 'ape effect' (tsk!) Yes, no direct hits are needed, the magnetic field alone from proximity hits or even cloud to cloud strikes will still cause an EMF ( or EMP) pulse enough to destroy.

I'll now peruse the lightning link on the board but still hope there are a few souls out there with experience in 'hardening' equipment. Coming from a calibration lab environment I distinctly remember when this was a big 'topique du jour' during the cold war days and it involved a lot of thick shielding, ferrite chokes, faraday cages and by-pass capacitors. Neither easy nor cheap but I was hoping the little dogies of technology had moseyed along a bit since then.