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lightning/surge arrestor installation

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defed

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i found some lightning arrestors, that i forgot i had, in my original box of equipment from a few years ago. i don't know why i never put them on, but figured i probably should. the plan was to put the DC one in the PV disconnect box and the AC one on the breaker feeding the transfer switch. i figure that this would isolate the charge controller and inverter.

the AC one has 3 wires, 1 for each leg and one for neutral. if i only have 120v do you just connect one of the wires? seems logical, but maybe i'm not understanding someting. there are not very good instructions, but i think it said to connect to the load side...is that correct?

thanks
 
The object is to protect your equipment from outside surges.
They should be placed between the equipment that you want to protect and the point where the wires enter the building.
And yes, just use the one wire and neutral for 120v.
 
KITROBASKIN said:
Can you tell us make and model of your lightning arrestors?
Click to expand...

delta LA302DC and delta LA302R. i also have a delta CA302R surge protector. can't seem to find much info, i've seen mixed reviews if they are even good quality. i got them quite awhile back.
 
timselectric said:
The object is to protect your equipment from outside surges.
They should be placed between the equipment that you want to protect and the point where the wires enter the building.
And yes, just use the one wire and neutral for 120v.
Click to expand...

that's why i was going to put the DC one on the PV disconnect before it enters the charge controller (but does it matter which side of the disconnect it goes on). i suppose the AC one could be better suited at the main service, but not sure i want to mess around w/ that so i figured the next best place to protect the inverter would be the breaker between the inverter and transfer switch.
 
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defed said:
that's why i was going to put the DC one on the PV disconnect before it enters the charge controller (but does it matter which side of the disconnect it goes on). i suppose the AC one could be better suited at the main service, but not sure i want to mess around w/ that so i figured the next best place to protect the inverter would be the breaker between the inverter and transfer switch.
Click to expand...
That all sounds fine. It doesn't matter which side of the breaker. Whichever is easier for you.
 
Delta Can type arrestors may help the wires in the walls from bursting into flames but rarely will they protect equipment.
 
peakbagger said:
Delta Can type arrestors may help the wires in the walls from bursting into flames but rarely will they protect equipment.
Click to expand...

i got them probably 12 yrs ago, when searching the internet wasn't quite as good as it is now. I wondered how good quality they were. since i had been going all that time w/o anything, i figure it won't hurt to get them installed.

what would you recommend to use?

just found a video where they test some. granted, it's midnite's video. they put a 22,000v surge into them. theirs clamped it down to 900v while the gray one (presumably delta) was still 7000v.
 
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are the midnite solar units the preferred ones? or is there another/better option?

i forgot i have the outback version installed on my inverter already. that seems to be designed more along the lines of the midnite as opposed to the deltas.
 
I think the midnight solar's are resonably priced and have a good rep. I had a name brand whole house unit on my house that looked beefy but when I swapped it out I opened the case, the components were not very large. Good luck to anyone ever trying to collect the various guarantees on the various brands, there are so many "outs" to avoid paying that I expect few ever collect.
 
peakbagger said:
I think the midnight solar's are resonably priced and have a good rep. I had a name brand whole house unit on my house that looked beefy but when I swapped it out I opened the case, the components were not very large. Good luck to anyone ever trying to collect the various guarantees on the various brands, there are so many "outs" to avoid paying that I expect few ever collect.
Click to expand...
Look into EMP shields (not for the emp part) but for the lightning part. I talked to a rep before purchasing mine and he said they have never denied a claim. They say the have a $25,000 insurance policy. If it gets hit with lightning (one time is all it can take) they will replace for $50. A lady had the display on a microwave go out (anything plugged in is protected if you have one on your electrical panel) so they bought her a new microwave. I got mine for $50 off (offgridbrian is the code) and then they were also 10% off at the time. BEEFY. These guys sell to the DoD.
 
I have 18 MNS SPD’s. Two lightning strikes within 300’ blew one tree apart. PV circuit must have had some induced EMF causing trip of my SA12K for two minutes. All is good weeks later. All blue LED’s on.
 
SniperX said:
Look into EMP shields (not for the emp part) but for the lightning part. I talked to a rep before purchasing mine and he said they have never denied a claim. They say the have a $25,000 insurance policy. If it gets hit with lightning (one time is all it can take) they will replace for $50. A lady had the display on a microwave go out (anything plugged in is protected if you have one on your electrical panel) so they bought her a new microwave. I got mine for $50 off (offgridbrian is the code) and then they were also 10% off at the time. BEEFY. These guys sell to the DoD.
Click to expand...

they are pricey, but if it works i guess it's worth it. i will have to do a little more reading on them. the code you gave still works and there is another 10% off (though they do cheat a little and take the 10% off the price after deducting the $50 rather than before, but it's better than a sharp stick in the eye).

i think most are hooked up the same, but he shows it being put into a 220v 20A breaker. so any breaker placed anywhere in the panel will be adequate for protection? i presume this is an empty breaker because only certain breakers allow for more than 1 wire per terminal. i do have 2 open slots on 1 side, so i could install one in there.
 
RV10flyer said:
I have 18 MNS SPD’s. Two lightning strikes within 300’ blew one tree apart. PV circuit must have had some induced EMF causing trip of my SA12K for two minutes. All is good weeks later. All blue LED’s on.
Click to expand...

i may need up to 3, so the emp shield may be too pricey for that...seems the midnite's have a good reputation, i will have to do more reading.
 
Does Will have any info/reviews on surge suppressors? I don't see anything on his youtube.
 
RV10flyer said:
I have 18 MNS SPD’s. Two lightning strikes within 300’ blew one tree apart. PV circuit must have had some induced EMF causing trip of my SA12K for two minutes. All is good weeks later. All blue LED’s on.
Click to expand...
Absolutely.
Not cheap, but well worth it.
Look at the videos comparing MidNite Solar to others.
 
I really like the Midnite Solar. Simple to install, look great and have a nice visual indicator.
I'm going to add a few more when I put the next array and new AIO up in the next month. I'll also look into the "EMP" protectors.
(I take no credit for the wiring in the panel on the right side)
18 @RV10flyer. Wow! ?? ??
 

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defed said:
delta LA302DC and delta LA302R. i also have a delta CA302R surge protector. can't seem to find much info, i've seen mixed reviews if they are even good quality. i got them quite awhile back.
Click to expand...

ROTFLMAO!

defed said:
Does Will have any info/reviews on surge suppressors? I don't see anything on his youtube.
Click to expand...

I got yer reviews right here !

diysolarforum.com

Delta LA 602 Lightning Arrestor "Hey! Is this thing on??"

I've been using Delta Lightning Arrestors on my system since they were spec'd by Real Goods as part of the package I bought from them. I now have a surge capacitor on the AC input as well, which is supposed to slow rising edge of voltage so it doesn't get as high before the Silicon Oxide...
diysolarforum.com diysolarforum.com

diysolarforum.com

Testing Metal-Oxide Varistors (MOV)

Surge arrestors are used on AC and DC side of PV inverters for protection, to clamp high voltage transients. One inverter I have (actually several) are in the SMA family SUNNY BOY 5000-US / 6000-US / 7000-US / 8000-US. These come with a kit of MOV to protect the DC side: The MOVs are about...
diysolarforum.com diysolarforum.com

I just offer dry text and measurements.

Midnight's videos are more entertaining.

I think the Delta "arrestors" *might* flash over and clamp extreme events.
I definitely recommend using MOV, whether in addition or instead of.

I provided links to some DigiKey MOV similar to what SMA puts on the PV side.
Those could work on AC side, but I like the idea of PTC fuse to open-circuit if MOV shorts, which Midnight uses.
I bought some, mean to install one of these days ...
 
Surge suppressors work better with some wire resistance in incoming path from AC mains, so better protection is achieved with surge suppressor close to inverter AC input, at least for inverter.

On three wire split phase surge suppressors there is just three MOV's between each of the three wires. If you only have 120vac then place the L1 and L2 surge suppressor wires to the 120vac source. It will double the clamping current for a voltage spike.

Make sure they are connected to common ground and be aware of too much ground path wiring resistance.
 
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