Last night we had a heavy Thunderstorm here south of Hua Hin/Sam Roi Yot. Around 1.00 AM I heard a very loud bang and the Aircon went off for some seconds even with installed ESS.

This morning then I've checked the entire Electric System in my Buildings and found several MCB's and RCBO's tripped plus a total of 11 LED Downlights were blown and needs to be replaced.

As I have Surge Protectors installed in all Consumer Boxes I'm wondering how this can happen.

Even the best surge protection isn't an absolute guarantee, particularly for a very close strike.

 

What is the kA rating of your surge protectors? Do verify that the "failed" flag isn't showing.

 

You may want to add some of the small, round, surge devices to your LED lights, they are really cheap but do ensure that they're not near anything flammable.

As @Crossy said but to be more insistent. It is extremely unlikely that you will have a lightning protection system that will negate a near or close high energy strike.

 

It is certainly possible to do the work and spend the significant price to virtually stop damage from even a direct hit. However the work is significant and the costs run into the hundreds of thousands of dollars.

 

So the costs of a few replacements lamps and electrical items is insignificant related to the cost of protecting them.

 

Lightning strikes are not common enough for most people to want to spend that kind of money.

 

if you are in a high risk area, like some Japanese golf courses, then you take precautions, they have lightning protection bunkers on the courses. Or if you are outside then you need to understand how not to be a target (regrettably one of our villagers didn’t do that a year or two ago with a deadly result) 

 

So far my minimal precautions have resulted in zero damage to anything I own for over 70 years. Luck? Maybe. The results of being sensible? Possibly. If I get any damage then the amounts of money I haven’t spent over the years are more than enough to cover the costs 

 

 

2 hours ago, Crossy said:

Even the best surge protection isn't an absolute guarantee, particularly for a very close strike.

 

What is the kA rating of your surge protectors? Do verify that the "failed" flag isn't showing.

 

You may want to add some of the small, round, surge devices to your LED lights, they are really cheap but do ensure that they're not near anything flammable.

I'm using Schneider Square D SPD with a 20 kA Rating, but the LED Light is still green. Looks to me they are still ok.

20kA is at the low end of what would be considered as "adequate" for a main suppression device, I also believe that the Schneider units only protect L-E rather than L and N to E (I may be wrong here mind).

 

Of course, they are far better than nothing.

 

I would consider adding an 80-100kA 2-pole unit next to your incoming supply (assuming you are single-phase) give it a nice straight, meaty, earth to its own rod if your main rod isn't reasonably accessible.

 

Also, if you have remote buildings, I would add similar 2-pole units at the building incoming locations.

 

You don't have to spend a fortune, there are many suitable units from China in the 500-1000Baht region which won't break the bank.

 

We were also losing LED fixtures more often than I liked, so each one now has a little 6kA beastie in the fitting. They are cheap but do ensure that they can't set anything on fire if they fail!!!!

 

I got a bag of these chaps from NPE ages ago https://www.bourns.com/docs/product-datasheets/mov20d.pdf

 

 

 

3 minutes ago, Crossy said:

give it a nice straight, meaty, earth to its own rod if your main rod isn't reasonably accessible

 

On that note, its would be a good idea for the OP to check all existing surge devices have the essential solid ground connection.

1 hour ago, Crossy said:

20kA is at the low end of what would be considered as "adequate" for a main suppression device, I also believe that the Schneider units only protect L-E rather than L and N to E (I may be wrong here mind).

 

Of course, they are far better than nothing.

 

I would consider adding an 80-100kA 2-pole unit next to your incoming supply (assuming you are single-phase) give it a nice straight, meaty, earth to its own rod if your main rod isn't reasonably accessible.

 

Also, if you have remote buildings, I would add similar 2-pole units at the building incoming locations.

 

You don't have to spend a fortune, there are many suitable units from China in the 500-1000Baht region which won't break the bank.

 

We were also losing LED fixtures more often than I liked, so each one now has a little 6kA beastie in the fitting. They are cheap but do ensure that they can't set anything on fire if they fail!!!!

 

I got a bag of these chaps from NPE ages ago https://www.bourns.com/docs/product-datasheets/mov20d.pdf

 

 

 

Thanks, will talk to my Electrician, but have 3 phase Power Supply for all four Buildings. All of them having their own CU.

And don’t forget to replace them periodically. Each hit uses up some of the energy absorption life in the MOV. I’m on the US Gulf coast and we see very similar situation. Every ten years or after a couple strikes within 50 meters . 
 

if i remember correctly, when that green led goes out, there is zero protection left. 

18 hours ago, UWEB said:

Thanks, will talk to my Electrician, but have 3 phase Power Supply for all four Buildings. All of them having their own CU.

 

You need to get 4-pole arrestors then 🙂