Can grounding *invite* surges?

What is being damaged?  devices on the DC side or the AC side?

Do you use SPD's on the DC and AC; ones like Midnite's?  Or delta's, or both?  I believe John Wiles of SW Tech recommends both to be used together.

Do you have roof top air terminals (lightning rods) along with its own very well grounded rods and or plates?


We made it through 5 years of use before we were struck, probably multiple strikes during the same storm. We added the Midnite SPD's and the roof top air terminal system after that. That system is separate and uses multiple grounding rods and buried copper ground plates. The rods and plates are placed in areas that have rainfall water directed to them in an attempt to maintain the soil moisture to be high enough to promote the best "earthing". Since then we've had further strikes but only had to have the Midnite SPD's replaced under the warranty and repair a fault in the array to chage controller wiring. That was/is a mystery. but no other damage.  One further change we made was to set up the DC input wiring to the CC in a manner that makes it easy to disconnect and separate the wire from the CC by 10 feet. We do that when storms roll through during our lightning season of July - August.

The AC electrical system has been grounded from day one.

Sure.  

Warning:  My solution will most probably not pass an NEC inspection. Our cabin is remote and sort of hidden.  A word picture will have to do.

Our panels are in series for a rated Voc of 108.3 volts and Isc of 8.3 amps.  The conduit from the PV used to come up out of the erath at the SE corner of the cabin.   I installed a treated wood post twelve feet from that SE corner. I dug up the conduit and reconfigured it to rise on the downhill, facing PV array, side of the post. 

I installed a weather resistant Midnite box fitted with a DIN rail MNEPV breaker on the post. The wire coming from the PV is 2 AWG. I used a connector made to transition from 2 AWG the breaker connector. The positive DC line is connected to that breaker. There is also a terminal block for the negative and ground wires to downsize. This box is the location of one of our Midnite SPD's. Another MN-SPD is installed down at the PV array pole. Both of these locations also have delta lightning arrestors. Belt and suspenders approach. 

The wires then connect through fittings and conduit to an outlet box, weather proof type on the other side of the post. That box is fitted with a NEMA L6-50 twist lock outlet/receptacle. (female connector). Both sides of the post have warning labels I had made up on rain and sun proof sign stock. They warn against inserting or removing the NEMA plug without first pulling the breaker to off.  It is not foolproof, I know, but the warnings are very visible.  I know these are not DC rated, but the contact surfaces are robust and they are not to be plugged in or unplugged when powered. 

I then have an outdoor quality  10-3 cord with the matching L6-50 male plug on one end. The other end of this cord connects to The Kid  charge controller, via another MNEPV breaker installed just before the CC. The cord can be unplugged, coiled up and stored inside a box on the cabin wall.  There is a third MN-SPD installed at the CC position. Also an AC version of the MN-SPD is connected at the AC service panel. 

This works for us. We don't let others use the place when we are not there, except for one family member. 

The SPD green wires / electrical system grounds are connected to a series of 3 copper clad rods and 1 buried copper plate. All connected with a single continuous length of bare copper. Earthing points are separated by something like 12 to 15 feet. 

Our air terminal lightning protection system is also earthed to 4 copper rods and 2 buried copper plates, but separate and on the other side of the cabin. 

If running ungrounded, I'd put a GFCI on each circuit.    These prevent most cases of electrocution.

Also consider installing a perimeter ground to divert differences in ground potential around your house.  

Do you have a grounded well pump?

than ks Dave..  just 2 weeks ago , days before this onslaught,  our neighbourhood Helicopter base erected a new comm tower...  we watched it go up and left for grits etc, and came back 3 days later to....No Tower???  Bino's out , no tower, the next day it went back up and we overheard on the ICOM that  '' it looks like it was only the radio equipment that got nailed''   Yup 2days before it got blasted, now I watch the show at night  waiting to witness the ;fireworks, We are happy to have a higher sacrificial lamb up there on the ridge !!

Those chopper lineman are amazing.  We look out into 2 river canyons out of Yosemite and the high voltage for the park is about 10 miles away.  When there is lightning I can see it dance off the guy wires. We don't get alot of lightning but we can get it at anytime of year. There is always someone here to shut it down if it gets close.  We still pray though.....