Hi sir, I change the RCCB to ABB 30mA half year ago, but recently my RCCB keep trip, even I off the MCB, RCCB still unable to switch on, need to wait for 10 minutes only able to switch on the RCCB.

Sometimes it trip within 30 minutes, sometimes can last for half a day. I had try to off all small mcb, only on main MCB and RCCB, still trip after hours. May I know roughly what is the issue please? I have no idea to ask technician to check for which issue.

Please advise, appreciate.

This post has been edited by FyChai: Aug 13 2024, 01:25 AM

Neutral leak to earth
Mcb only control live.

Do you mean its my neutral (black) wire issue?

yes. remove all the neutral, check one by one which one got low ohm to earth

Delay trip. sometimes can be caused by those fluorescent lightings.

Possible grounding broken, maybe check grounding cable as well.

Checked 1 neutral cable is low ohm to earth, wireman ask me to pull new cable since it fault. May I know do I just pull new neutral cable or pull live cable with it also?

check why low ohm first. could be something simple like the light socket busted.

ya if have the opportunity to lay new cable, do sekaligus live neutral earth.

Can I check myself and how to check please? The neutral with low ohm link light and fans, Wireman said need extra charge for the checking on light and fans and it cost a lot. Now we had disconnect the neutral, DB didnt trip again.

the low ohmed neutral wire is removed, right?

check whole house, which socket or light does not work.

for socket, remove all plugged in devices, including extention socket

for light, remove if possible.


then use a multimeter to measure the ohm of the neutral to earth again.

Yes the Neutral removed, 10 lights and 1 fan doesn't work now. Its ceiling light and downlight, how to remove please? Just unplug the light bulb？

low ohm means what value ? should be below 1 ohm ,

possible the light,or fan or wire leakage .
disconnect the neutral of all lights and fan . neutral point just before the light .
connect back the neutral at the DB .
observe if trip

do inspection of the wires , connectors , see its secured good/ not broken / expose and not touchin light body .
check also the fan wire contacts secured and not touch fan body

you looking for any damage wire cover

takes time to DIY
isolate 1 by 1 of the circuit .


This post has been edited by Momo33: Aug 15 2024, 11:24 AM

ok great
i think its the fan because light bulbs dont have ground.

some crazy electrician install downlight using the earth wire as a hook. it is also possible the ground wire strand touched neutral.

My house using 3 phase, saw wireman use the isolator checked 0.5 ohm at 500v.

May I know the name of isolator and roughly price? The wireman charge RM400 for checking, thinking to DIY or let him do it if the isolator expensive.

This post has been edited by FyChai: Aug 15 2024, 01:19 PM

Wireman charge RM400 for checking, May I know is it reasonable price or go buy isolator DIY? Its just 1 neutral connect those light and fans. At the end if wire issue need to pay another thousands for pulling new wire. Swt..

the tester is a insulation tester or megger . shopee have but not sure quality

since you know its the wire loop for lights and fan can try DIY . to find where the fault is.

so faults can be in the wiring , connections , fan and lights

disconnect the fan inputs . L N E
and all those easy lights
check if rccb trip.

if you disconnect all devices and still trip ..then wiring have issue.
ensure all wiring not touch any case , and not damage .

its time consuming but if you have the time just DIY as above first.
I am assuming you have a multimeter cos need to check resistance of wire if need . disconnect the L N E at DB box .


wiring seldom fail cos the lights circuit dont carry heavy current to melt it.




This post has been edited by Momo33: Aug 15 2024, 02:28 PM

Go get yourself a multimeter. You can try diy first
If fail only get the pro.
It's simple enough.

If don't have multimeter just connect back the neutral wire to the screw block

If found the rosak device then won't trip

Ok, i try to disconnect light and fans wire one by one and connect back the neutral to test it. Btw, what is the multimeter you mentions please? Maybe i can buy from electrical shop for DIY

You can get uni-t digital meter
Or sunwah analog meter.
The analog meter will be easier to use for your case.
The digital meter is more versatile

https://shopee.com.my/PRO%F0%9F%8F%A0UNI-T-...93-0f5e4fd36720



specs.
Range UT123
Certifications RoHS
Category ratings CAT III 600V
DC voltage (V) 600V ±(0.5%+2)

AC voltage (V) 600V ±(1%+3)

DC Current (A) 10A

AC Current (A) 10A

Resistance (Ω) 20MΩ ±(0.8%+2)

40MΩ

Temperature -40~300°C ±(1%+5)

-40~572°F ±(2%+6)

Capacitance (F) 4000μF