B, C, D types are for the inrush current.. Domestic uses type B

Ampere rating are for current overload protection of the cable. Size the amps according to the cabl's current carrying capacity..

Scroll to the btm of the page, the link at the btm.. Read it.
Suruhanjaya Tenaga - Guidelines for Electrical Wiring in Residential Building 2008

Is this a new installation and is it a new mcb?
If yes then its probably this circuit is overloaded causing a thermal trip.. Get a clamp ammeter and cheack the load and compare it to the mcb's rating.. If overloaded then remove part of the load to another circuit (If it's more that one load on the circuit)

If no (meaning it was working well previously) then listen carefully to this particular mcb.. If you hear small crackling sounds before tripping then replace the mcb. The mcb has pitted contacts, that means the contact area has reduced to the point where it itself causes the thermal overload.. The device is faulty..

You only replace wiring if the insulation is damaged and you test with an insulation tester (Meggar).. Hire an electrician for this.. He has the equipment and competency to use it.. You cannot use a multimeter..

This picture shows a Three phase Distribution board (DB)..

It's protection device ia a 4 pole Residual Current device (the one with the yellow trip button)

The RCD is for 3 phases that's 100mA trip per phase..

Whether yours (0.1A) more sensitive depends if you have 3 Phase supply ..

meaning is your RCCB 2P or 4P?

If 2P then i think it is not more sensitive..

Firstly, use the correct terms for the components, it helps avoid confusion..

A fuse cannot kick back.. It is a fusible link.. It blows (meaning gets hot, melts thus disconnect) when over rated current flows through..
A miniature circuit breaker (mcb) trips (meaning there's a bimetal contact which trips a spring) when over rated current flows ..
You replace a fuse.. You reset an mcb (only replace if faulty)..


Yes, it is possible.. This is a forum and I'm just giving my opinion. You need an actual competent person to repair it.. (An electrician)

However the fuse or mcb function is to protect the wire.. It blows/trips before the wire gets hot.. A 1.5mm wire is rated at 23Amps..

A 32A fuse/mcb cannot protect a 1.5mm wire.. The wire will melt and burn anything combustible close to it..
It might burn down your house.. Pls understand your risk..

Hire an electrician if you don't know what I'm talking about.. It will save you more..

ok..

Standard domestic wiring regulation requires you use 2.5mm2 or higher size wire for sockets..

When new the metal within the wire is pure .. An older wire oxidizes and its insulation degrades.. It cannot carry rated current and heats up when over current..

Regulation states you must completely rewire after 30 years.. I rewired my house after 20 years.. It's my insurance..

Good luck..

This post has been edited by Richard: May 10 2016, 03:42 AM

Yes.. Switch off all your miniature circuit breakers (mcb)..

Standard wiring mcb's all type B's except motor (if nuisance tripping then use type C or D for higher inrush(start) current)
-------------------------------------------------------------------------------------
6A & 10A are lighting mcb's
16A & 20A are socket/aircon/water heater mcb's
32A are cooker/large freezer/3HP & above motor mcb's

- Switch on only one mcb
- Visually check which one has power and record on the mcb
- Switch off
- Repeat next mcb..

Seriously..? I myself am certified with ST but i get an electrician to do the work.. For me it's a matter of cost and speed.. I can talk the talk but crawl the walk if you get what I mean..

For you I think it will be an additional safety issue.. Wiring a whole house with 20-40 points is not an amateur DIY..
One point is ok.. Not whole house.. you're crazy to think you can do it..

You use a water heater for hot water..

You use a 10mA RCD to protect your life from electrocution from the water heater..

Why would you value a 10mA RCD higher than life?

Edit * Watch this youtube video.. It is good .. https://www.youtube.com/watch?v=A5HuPol99sU

I also find it pretty funny ..

This post has been edited by Richard: May 8 2017, 09:58 PM

I might have actually ... when you typed " I'm protecting the RCCB because it's much more expensive." ..

My mistake..

Your setup is a standard arrangement i.e. The RCCB (or RCD) doing the protection of life, while the MCB protection for the property (cable, RCD & load)..

It's good..

I only experience seeing type C in the market..

Physically the difference is nominal (I.e. in name only), as it deals with the breaking capacity of the breaker.. thus the physical characteristics of the spring.. you would need a department like SIRIM to be able to tell the difference..

You and me, we take and accept what is available..

Correction..

On a 20A Type C MCB, Once there is an overload current meaning more than 20A the breaker will trip .. There's a coil within which pulls in a metal piece (an electromagnet) which trips out the breaker..

Type B, C and D only refers to the inrush current .. produced by inductive lighting and motors.. The 5x is a transient (momentary or short time only) current during the start to enable starting torque(of a motor) or to jump a spark (of lights)..

Once the motor is running or the lamp is lit, the current goes back to rated normal..

A continuous flow of overload current (beyond 20A) will heat up a secondary part of the breaker (a bimetal strip)..

Your friend is misinformed .. A MCB protects against an overload (both magnetic and thermal type), a RCD protects against leakage current (below the rated) but will kill a person..

You need both devices in your DB, one to protect property, the other to protect life.. It is a mandatory (MUST HAVE) requirement..

For the secondary RCD at the water heater I believe it is only recommended not yet enforced by our Suruhanjaya Tenaga..

If you read the news then you know that people have died due to faulty electric water heaters .. 50mA AC Voltage over 5 secs will kill a fully grown 60kG human male..

You can google, read it up or ask any medically trained person.. The symptom is similar to a heart attack with burns at the contact areas..

Edit*

If the device keeps tripping then there is a leakage current, dirty equipment in a high humidity environment is the usual cause...

The dust settles on the live or Neutral wire and when wet will leak to a conductive cover tripping out the RCD..

You need to clean the electrical devices.. Wet dust can conduct electricity..

Edit**

Correction For the secondary 10mA trip RCD at the water heater.. It is a mandatory requirement by Suruhanjaya Tenaga..

This post has been edited by Richard: May 20 2017, 08:43 AM

No. An Aircon compressor motor starts/stops multiple times acting on thermostat sensor

The starting amps will be 6x or higher and will burn out the mcb or connectors contacts. There will be arc damages initially slowly continuosly damaging the contacts and burn.

Any 4 Ampere Aircon compressor motor must have a dedicated circuit protected by a 20A mcb.

Only a single 1hp Aircon to one circuit. No more.