Lightning/Surge Protection Check: Midnite Solar SPDs and Gas Tube Coax Arrestors

[Dhowman]

With a history of one direct hit and one nearby strike, I'm kind of keen to do what I can to protect as much of my new solar system as possible from surges, esp my LFP bank. The direct hit was to my work truck on a hillside in NV that vaporized my CB antenna, fried my truck, exited at a wheel rim and tunneled 10 feet to a nearby camper through a jackstand, which essentially became welded to the camper and ground underneath. The nearby strike was to a sailboat in a marina that was docked next to mine. All of his electrics were toast (despite having a diffuser on his mast head). Mine (without one), surprisingly, escaped damage. Fortunately, neither occurred when anyone was around.

So, I did some research into what I could add to my system and came up with these three things:

1. COAX from GPS antenna on truck camper roof will have inline Gas Tube Coax Arrestor.
2. Ditto for both COAX wires coming down from dual Yagis mounted on a 25 foot extendable fiberglass mast mounted to the back of my truck camper.
3. DC circuit protection via Midnite Solar MNSPD115 surge protector(s) (AC system won't need one).

From what little I've been able to glean about how the SPDs work, it appears I can install them one of two ways (see pic below):

• Option 1: One SPD between at each PV input just before my DSSRs and one directly at the DC power jack for my LTE Router (TOTAL=4), or
• Option 2: A single SPD at my 24V bus bar.

Granted, Option 2 should clamp any HV surge before it hits my battery but Option 1 would do it further away and could, conceivably, isolate downstream DSSRs, Breakers and Shunts too.

QUESTIONS:
Am I understanding correctly how these things work and the protection they provide?

1. Would Option #1 provide better protection for my LFP bank?
2. Any better options or specific recommendations on where best to locate these devices in my rig?
3. Plan to ground all these devices to truck and thinking, too, of grounding truck to earth via a copper spike I can drive into the ground when I'm stationary/camping. Make sense or totally unnecessary?

 

[nosys70]

you cannot stop a lighting, you can only offer a better/shorter path to the ground that is not passing through your equipement.
Diffusers of all kinds are just to minimize the needle effect you get on thin parts that stand in the air (like poles and antennas) but if the the lightning is close, even a diffuser will not change anything.
to offer a better path, usually you try to catch it as soon as possible on the metallic parts that are exposed.
A solid copper bar, shortest as possible, well grounded will be enough.
if you have wires coming down to some equipement, you will fuse them just after the ground point.
i think you can easily build yourself a device like copper tubes between 2 copper plates with the ground wire starting form that.
inside the copper tube you will run a wire that is very close to the wall of the copper tube without touching.
at the output of the copper tube you will install very long fuse wire so the wire will vaporize over a long distance..
ideally if you wires are going down close to the ground, you can shield them in the copper tube until you are close to the ground, and exit from the copper tube from there.
for vehicle or boat, it is more complex since you have no easy ground.

 

[svetz]

My planning is that if lightening hits you, your toast regardless of what you do, so plan for nearby strikes. There's also a thread on Surge Protection you might enjoy.

 

[svetz]

Mike Holt is the go-to guy for grounding... He doesn't like multiple grounding rods. Anyone have a link to where he talks about lightning?

 

[Dzl]

I'm also interested in this topic, I'd be curious to hear anyone's perspective on lightening arresters / SPDs, specific to vehicle based systems (no connection to earth-ground)