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Anyone disconnect PV array during lightning storms?

kolek

kolek

Inventor of the Electron
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Just wondering if anyone out there bothers to disconnect their PV array or any of their other equipment during lightning storms.
(In the case of disconnecting the PV, I'm aware you'd want to reducing PV current down to the lowest possible level to prevent arcing during disconnect)
 
Assuming you're grounded correctly it shouldn't have too big of an effect either way. Your disconnect should not disconnect the grounding. The direct grounded path ought to be the path of least resistance. There's probably some inductive shit that can happen, but IDK if an open circuit is gonna change anything there.

Doesn't hurt to have surge protectors where you are able to put them. It's code to have


Current code 2020 & 2023 is to have a surge protector at either service entrance(s) or each panel. It's possible to have both.
 
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robby said:
No but weeks after my installation a bolt hit the power line not far from my house and sent my Inverter into a fault.
The next day I bought a Surge suppressor and have never had the issue again.
I bought the cheaper $90 version to this one.
Surge Protection

I also have the Surge protectors for the PV that @Citlalatonac linked.
Click to expand...
Also, if I've listened to Mike Holt correctly your inverter is it's own service same as grid connection in 2023 code (and arguably 2020) and would therefore need it's own level 1 SPD if going that route.

Parinoia dictates both type 1 & 2 SPDs and everything individual item plugged into their own surge protector strip or UPS.
 
I put Midnite SPDs near the arrays and inside. I did used to disconnect them when I installed my first array but since then just leave them connected. For disconnecting if you have a proper DC disconnect such as an IMO it isn't necessary to reduce the current before disconnecting.
 
kolek said:
Just wondering if anyone out there bothers to disconnect their PV array or any of their other equipment during lightning storms.
(In the case of disconnecting the PV, I'm aware you'd want to reducing PV current down to the lowest possible level to prevent arcing during disconnect)
Click to expand...
I'm pretty sure that anything higher than what a SPD can handle is gonna bridge the gap in your disconnect unless you're physically disconnecting all the wiring going to your array :unsure:
 
This is a quote by AntronX below is a thread the quote is from he makes very valid points in this thread.

This should help explain the way surge protection is supposed to work.

AntronX:
Bob B said:
You didn't answer my question .... where would you be shunting the voltage spike?
Click to expand...
To a common low impedance ground point so that differential current across the lines entering your building would not develop. You don't actually need to shunt it to earth ground, you need to shunt it to a common point of a ground system akin to a Faraday cage. This is why being inside metal car keeps you safe from lighting even if the car is not grounded. But that is also not completely correct way of protecting your equipment from lightning surges. All your lines entering the building have to enter at one physical point or be routed to one common ground point before fanning out to you equipment. This is called single point grounding. This eliminates a possibility of differential current developing across lines due to ground system impedance that will always be there.

diysolarforum.com

Lets Play Sherlock Holmes - The lightning incident.....

Any time we had wiring of any kind exiting or entering a building, we always put lightning protection at both ends. Most of the time a lightning strike would take out the protection and still get our equipment. Well there is a reason I'm all over this method being discussed and it is ALL based...
diysolarforum.com diysolarforum.com
 
Well one thing to keep in mind (since I'm the one that made that thread) is the lightning/surges came back repeatedly till I started turning off the pv breaker. My theory is since those wires didn't actually go anywhere after being disconnected the ground path was much more "interesting" to the surges path so it didn't go down those wires since they didn't go to anything anymore. Again just how I figured it would work and it stopped doing it after turning them off.

Also I found out later that the surges were coming from the water pipes not the pv wires. I moved the pv wires to a different entrance point away from the water lines and it stopped even with the breakers on. But I still felt warm and fuzzy cutting them off when the sparks are flying around outside.
 
Crowz said:
Well one thing to keep in mind (since I'm the one that made that thread) is the lightning/surges came back repeatedly till I started turning off the pv breaker. My theory is since those wires didn't actually go anywhere after being disconnected the ground path was much more "interesting" to the surges path so it didn't go down those wires since they didn't go to anything anymore. Again just how I figured it would work and it stopped doing it after turning them off.

Also I found out later that the surges were coming from the water pipes not the pv wires. I moved the pv wires to a different entrance point away from the water lines and it stopped even with the breakers on. But I still felt warm and fuzzy cutting them off when the sparks are flying around outside.
Click to expand...
never minder
 
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I have a pretty good industrial strength whole home surge suppressor on the AC input from the utility.
But haven't invested in the Midnite Solar SPDs on the PV lines yet. If anyone can recommend a cheaper decent solution I'd love to hear it.
 
rhino said:
I put Midnite SPDs near the arrays and inside. I did used to disconnect them when I installed my first array but since then just leave them connected. For disconnecting if you have a proper DC disconnect such as an IMO it isn't necessary to reduce the current before disconnecting.
Click to expand...
>I put Midnite SPDs near the arrays and inside
So you have 2 Midnite SPD's on each PV line? In my case that would cost 8 x $125 = $1000.

>if you have a proper DC disconnect such as an IMO
The only DC (PV) disconnect I have is the one built into the Deye inverter, which likely is a piece of junk. I deliberately have not installed DC disconnects because of their reputation as fire hazards. Figure not having them (aside from what's built into the inverter) is one less component that could fail or cause a problem.
 
robby said:
No but weeks after my installation a bolt hit the power line not far from my house and sent my Inverter into a fault.
The next day I bought a Surge suppressor and have never had the issue again.
I bought the cheaper $90 version to this one.
Surge Protection

I also have the Surge protectors for the PV that @Citlalatonac linked.
Click to expand...
I have seen more issues from the utility side than any solar array. The ground/neutral that least out to the utility lines is either a path in or out from your home. If it hits anything on your home it goes down the ground rods out the neutral to the pole. The same is true if it hits the pole and comes down the neutral to your ground. Surge arrestors to keep the difference of potential reasonable it a fantastic idea. It is going to go somewhere why not direct it all to the ground.
 
kolek said:
>I put Midnite SPDs near the arrays and inside
So you have 2 Midnite SPD's on each PV line? In my case that would cost 8 x $125 = $1000.

>if you have a proper DC disconnect such as an IMO
The only DC (PV) disconnect I have is the one built into the Deye inverter, which likely is a piece of junk. I deliberately have not installed DC disconnects because of their reputation as fire hazards. Figure not having them (aside from what's built into the inverter) is one less component that could fail or cause a problem.
Click to expand...
The one in your inverter is designed to disconnect under load just as the IMO it's got similar design characteristics and specifications it should not be that dissimilar
 
Unrelated question, do you put these Midnite Solar SPD's on both the positive and negative PV lines or just 1 is sufficient?
 
Bananaman321 said:
The one in your inverter is designed to disconnect under load just as the IMO it's got similar design characteristics and specifications it should not be that dissimilar
Click to expand...
In theory, right, but I really am not happy with the quality level of the parts I can touch and see on the Deye inverter. For example the PV input terminals/connectors are loose plastic junk that probably cost Deye about 10 cents a piece. The plastic levers which are supposed to clamp the wires are so floppy and loose they are likely fire hazards. Just my opinion. I know some people like Deye, I just don't happen to be a fan.
 
BarracudaBob said:
I have seen more issues from the utility side than any solar array.
Click to expand...
Glad I at least have that side covered. My concern there is the size of the wires going from the whole home surge suppressor to ground and neutral seem a little to thin to dissipate a large surge.
 
kolek said:
In theory, right, but I really am not happy with the quality level of the parts I can touch and see on the Deye inverter. For example the PV input terminals/connectors are floppy loose plastic junk. The plastic levers which are supposed to clamp the wires are so floppy and loose they are likely fire hazards. Just my opinion. I know some people like Deye, I just don't happen to be a fan.
Click to expand...
It may be of lesser quality and probably won't last as long but it's still a spring loaded throwover with some device to extinguish the ark

That being said the ship performed a task at hand I would just avoid using it more than necessary

I have a PV disconnect on my inverters that disconnects all 3 inputs at once and then I have 3 IMO disconnects one at each of 3 arrays and one of which parallels a 4th array.
 
I agree that that small ground wire isn't going to do it. #6 is minimum I would trust.
1721536508822.png

That energy is looking for a path to ground. The faster it gets there the less you will have to worry about it. 2 DC wire on PV line, 2 240V coming in to home. Cable, TV, Phone, and anything else should have surge/MOV arrestors to channel that energy to ground. Difference in potential is the killer.

Here is a picture where it blew the cable TV coax off the house. Ground worked and no equipment inside the house was damaged.
1721536785388.png
 
AWG 14
BarracudaBob said:
I agree that that small ground wire isn't going to do it. #6 is minimum I would trust.
Click to expand...
The ground and neutral lines coming off the Schneider Electric Square D HEPD80 are probably AWG 14. The unit claims to have 80kA per phase of suppression.

Is there a suppressor that comes with AWG 6 or larger wires to ground/neutral?

Having said that, the entire grounding system in this old Japanese house is AWG 14 wires so it's not fixable short of modernizing and rewiring the whole house.
 
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kolek said:
AWG 14

The ground and neutral lines coming the Schneider Electric Square D HEPD80 are probably AWG 14. The unit claims to have 80kA per phase of suppression.

Is there a suppressor that comes with AWG 6 or larger wires to ground/neutral?

Having said that, the entire grounding system in this old Japanese house is AWG 14 wires so it's not fixable short of modernizing and rewiring the whole house.
Click to expand...
I am used to industrial units for radio towers. we used big ABB Joslyn Surgitron. For residential you may have to use multiple devices to make up for the small wire size.
 
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