Erm, what is the point we discuss RCCB on this matter? Its really trip after the neutral cable disconnect, and I use it for year, never trip even thunderstorm, the only disadvantages is expensive.

I'm not proffesional on eletrical, but the facts is it trip after the faulty neutral cable disconnect, and whole house short circuit with few appliances, bulbs, adapter burned. Wireman take hours to troubleshoot, issue solve after he connect back the neutral cable.

Base on I check on chatgpt, the answer also meet what the PW4 wireman said :

ChatGPT
No, you should not disconnect the neutral wire while leaving the live and earth wires connected, especially with the current on. This is dangerous for several reasons:

Electrical Shock Hazard: Disconnecting the neutral while the live wire is still connected can create a dangerous situation where the exposed wires or connected devices may still carry live electricity. This increases the risk of electrical shock.

Potential Damage to Equipment: If the fan or any other electrical device is designed to use both the live and neutral wires, disconnecting the neutral can cause improper operation or even damage the equipment.

Fire Risk: Without a proper return path (neutral), the electrical system may behave unpredictably, potentially causing overheating, short circuits, or fires.
I'm not going to argue anything, just want to know the truth and prevent it happen again in future. Anyone with relevant knowledge or experience can share info with me please, Appreciate.

the main purpose  of rccb  is to protect  human .  Not  appliance . 
rccb do not have over current protection .  you have MCB  for this.

The Malaysian  Tenaga recommendation  is 100mA  for  main DB , 30mA  for sockets ,  10mA for water heater.
new house  developer will put 100mA .
yes can use 30mA  but the risk is  more trips  when the wiring get old and degrade.  this depend  also if the  wiring is  first grade cable or cheap one. 

""I had checked with other PW4 wireman, if there is looping 3 cable on neutral, it mean more than 1 MCB sharing the neutral, simply disconnect neutral but didn't disconnect the live cable will cause short circuit and burn. Wireman should also check and disconnect the live cable.""
this explain above  i find no logic.  .  if remove  1 neutral wire  that part  circuit  will not function/ cos the wire  loop is not close complete  and current cannot flow. means that  bulb not work . 
its  shuld not  trip rccb. or blow  any
example if  1 wire for your  bulb  accident get loose/ or broke    that light dont work , and  rccb  will not trip .  right.

my guess  is he  not  connect/ tight  1 connection  cause sparking  , cause trip  rccb . 
my guess .