[RE-wrenches] [BULK] Diode Failure

[Jeff Irish]

We experienced a similar lightning event two years ago that destroyed over a dozen modules.  The system was a top of pole ground mount with four rows of four poles each, sixteen in total, arranged in a square.  The lightning strike occurred 150 feet off the southwest corner of the array, where it hit a utility pole.   All the damaged modules were in the front or south most row, and concentrated toward the southwest.  The module J-boxes were melted and deformed, with burned or exploded diodes.  That was the only sign of damage to the system.  The utility lost at least one pole top transformer, and the customer some appliances in his nearby farmhouse.  Fortunately the inverters were in a barn several hundred feet away.  Being a top of pole mount, the system was extensively grounded, with the steel poles at least 4 feet into the ground and lines of bare # 6 copper connecting them and multiple ground rods.

Jeff Irish
Hudson Solar
Rhinebeck, NY

From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Corey Shalanski
Sent: Tuesday, August 05, 2014 10:03 AM
To: RE-wrenches at lists.re-wrenches.org
Subject: [BULK] [RE-wrenches] Diode Failure

Wrenches,

We recently were contacted by a customer who reported a lightning strike close to his house. His online monitoring revealed that 30 of 35 microinverters simultaneously stopped producing power. On initial visit to the jobsite we measured Voc on many modules - either 12V or 24V instead of rated 36V. On a second visit we discovered that bypass diodes - either 1 or 2 corresponding to observed voltage loss - had failed on each of the faulty modules.

My question is: Can anyone support the theory that a nearby lightning flash can cause mass bypass diode failure?

--
Corey Shalanski
Joule Energy
New Orleans, LA
[Image removed by sender.]ᐧ
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140805/45dafd90/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ~WRD000.jpg
Type: image/jpeg
Size: 823 bytes
Desc: ~WRD000.jpg
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140805/45dafd90/attachment-0005.jpg>