hi

my house have 2 electric box (1st and 2nd floor)
during the rainny day with lightning (no matter small or big) there are huge change that my 2nd floor electric box trip however no issue on 1st floor electric box

even if you notice small lightning flash, it will trip my breaker as well
there is 1 time where we encounter lightning storm, my 2nd floor breaker can trip more than 5 times in just 30min
note: there is no lightning strike to my house and no issue if we just have rain with no lightning. it only happen when there is a lighning surge

anyone know why?
could it be my earth rod is not properly install causing my 2nd floor ground not good?

as far as i know my 2nd floor electric box ground connect to my 1st floor and use same earth rod
1st floor breaker never trip even during lightning storm


sorry that i am familiar with electric stuff

Have you asked an electrician?

Also are your neighbours having similar issues?

The most common cause is due to short/leakage to Earth and the resistance is high enough not to cause tripping (below RCD sensitivity) during normal everyday use, but easily trip during slight lightning surges.

Get an electrician to trace and fix the short/leakage. It could be from appliance, loose wiring/fitting, damaged cable etc. Beware and avoid lazy 'solution' such as disconnecting earth wire or RCD with lower sensitivity (higher tripping current).

So to troubleshoot need to turn off all appliances and turn on one by one when it happens & see which is the culprit? My case is terbalik, ground floor trip but first os ok.

No. If the leakage is from Live wire To Earth, the leakage is too low or it will already trip even during normal day. If the leakage is from Neutral or appliance (that don't have 2P switch/breaker), turning off MCB won't help as the Neutral wiring still connected to the busbar and only small proportion of the current will flow through the leakage.

It is actually easy to confirm if you have short/leakage to ground but I'm totally against anyone without sufficient experience and knowledge to DIY and open the DB themself.

So it's either live or neutral leakages that causes this tripping during thunderstorm? Can a knowledgeable electrician easily trace this?

There is no leakage per se, if there is a leakage said RCD alr tripped.

Sometimes its due to RCD from the 90s
a) aging >30 years tolerance all lari and/or
b) no "anti nuisance trip" filter technology

Replacing a 90s' RCD to a current model ABB solved nuisance trips for me.


ABB or Hager 30mA RCDs are the best you can get (easily) in MY market.

This post has been edited by ceo684: Sep 28 2023, 01:52 PM

Already changed to a Hager and it temporary stop the problem for a few months but lately the problem start again.

That's the most common cause. Even the most common RCCB (except the bottom bin crap) nowadays has anti-nuisance tripping. Knowledgeable electrician should be able find the shorting on the wiring side with ease (but maybe tedious) but they will need earth leakage clamp meter to confirm there is no leakage/short that only happen when the appliance is operational (such as compressor in fridge or aircon). But those appliance issue usually get identified over time unless you have high earth resistance. Earth leakage clamp meter is still useful to check the standing leakage current under the RCCB, which is recommended not to exceed 30% of the RCCB rating.

If the earth loop impedance is high, neutral short to earth may not even cause sufficient current to trip the RCCB. As the current is inversely proportional to the resistance, maybe not even 0.1% of the current from Neutral will flow to earth. On such cases, socket tester can't even trip the RCCB if the short happen downstream of the same RCCB as the socket tester.

This post has been edited by jio: Sep 28 2023, 07:42 PM