The conventional design for a building lightning protection system is a rolling sphere approach with Franklin rods. The lightning rods at the highest points of the structure connection via 25x3mm2 copper tape straight down the structure to an 16mm dia min earth copper rod to an earth impedance of below 50 Ohm.
Sometimes your electrical supplier can advise you as these are standard JKR building design.

The minimum earth conductor is 10mm2 for a 40 Amp main incoming and 16mm2 for 63Amp mains. For residential design.

You can refer to the attached guidelines or to Malaysian Building By-Law 1984 for confirmation as for me this all was a long time ago.

Hopefully I've uploaded the right attachement but note the Bahasa Malaysia version is the latest and my copy is an old code but should still be applicable.

Best wishes.

This post has been edited by Richard: Apr 6 2019, 04:48 PM


Attached File(s)
 guidelines_for_electrical_wiring_in_residential_buildings_.pdf ( 427.2k ) Number of downloads: 63

Yes, at the highest point and usually the TV and Radio antenna s are directly grounded. You will notice the tape around any government high structures or poles

Lightning protection is via copper tape is 25mnX3mm not 10mm2. The larger size to cater for lightning strike

DB home earthing can be a minimum 10mm2 pvc green wire
The sizing is calculated for the short circuit current
It's an estimate actually

Yes many housing development do not bother as there isn't too many people aware of this code and how to check the DB earth's impedance.

Maybe it's all old school.

Nice to see brother Westom still around. Hahaha

This post has been edited by Richard: Apr 6 2019, 04:42 PM

Conventional wisdom is to install an SPD (per DB rated kA or higher) before the DB to dissipate to mass of earth the lightning surge current. However I'm no expert so get a second opinion if you can.

The home DB's earth pit impedance must be as low as possible to maintain shortest path to earth mass. For landed properties only.

I would suspect your parents building earth pits are too high impedance thus the lightning surge randomly hit so many equipment

I would suggest you get a certified electrical contractor to check the structure electrical earthing pit (preferably 10 Ohm or better) system.

Edit* Anyway here's an easy way to check whether your home has good earthing.

Use your multimeter to measure the Voltage between Phase/Earth, if you get the same(or about 5V diff) voltage as between Phase/Neutral then you have good earthing. Fluctuates according to current weather/ground conditions.

Otherwise have your earthing checked by a certified electrician
If only you continually experience damaged equipment due to lightning strikes.
My house earthing is bad (I've checked) but no lightning damaged so I don't bother.

This post has been edited by Richard: Apr 7 2019, 06:47 AM

Yes

Ask to witness his earth testing method. He must use an earth tester to test your earth rod with a result of 10 Ohm or below

Let him setup his earth tester with a clamp to your earth rod. The remainder voltage/current spikes will be a few metres away.

Witness the 10 Ohm reading on his tester. Done.
.
Easiest way I know to get that reading is to locate your rod next to drain so it's wet most of the time. Anyway that is where I put in my earth rod and chamber. Just sharing.

Edit* Refer 8.2.4 the earth resistance testing method in the ST guidelines.

Attached JKR specs for lightning protection system


This post has been edited by Richard: Apr 9 2019, 06:39 AM


Attached File(s)
 guidelines_for_electrical_wiring_in_residential_buildings_.pdf ( 427.2k ) Number of downloads: 83
 JKR_LPS_Chap17.pdf ( 885.55k ) Number of downloads: 97

Earth impedance value

Transformer Neutral (star) pt and body - 1 Ohm or below

Residential electrical DB earthing pit - 10 Ohm or below

Residential Lightning protection system pit - between 5 to 50 Ohm or below
depending on soil conditions and consultant design.

Problem was some areas almost impossible to get the earth reading due to budget constraints. Needed to explain to the client and design engineer.

This post has been edited by Richard: Apr 9 2019, 07:34 AM


Attached File(s)
 4346628a_en_EarthGround_tutorial_e__1_.pdf ( 6.88mb ) Number of downloads: 79