Absolutely DO NOT do this. The MCB serves to protect everything downstream, and that includes the 2.5 mm² wires from overheating and catching fire. Changing the MCB from 20 A to 32 A means the usage of all the sockets may cause more than the rated amperes to flow in the wires, causing a fire.

Your best option is to pull new wires as you allude for the sockets that have high power appliances.

Your alternate is to only use a single appliance at a time from the group of sockets that are looped together. You may use more than one appliance together, but the total power used must be less than, say, 4000 W among all the looped sockets. (Edit: Suruhanjaya Tenaga's latest rating for 2.5 mm² wires are 18 A to 28 A depending on installation methods (which determines the maximum temperature the wires will reach), so you may have to install a 16 A MCB in the future for a total of about 3,600 W maximum power draw from the appliances)

In practical terms: (just example power consumption, please check your actual appliances)
1. The fridge is always powered, say 300 W. You use the microwave (1500 W). You are still okay with this circuit.
2. The fridge is always powered (300 W), you bake a chicken in the oven (2500 W), and then you soften butter in the microwave (1500 W). You are NOT okay now.

In number 2, the wires would have caught fire if you changed the MCB from 20 A to 32 A.

This post has been edited by stormer.lyn: Aug 26 2022, 09:12 AM

You relocated to SG? Story us some more.... when? Did you go for work, or for some other reason and then now working there? I guess this is good news, we make our own future, so best of fortune in yours!

I actually do commercial work now, since I left the O&G support company a couple of years back. But at the moment taking jobs from customers who are recommended by previous customers. This way, at least the outcome that I only want to do proper specced work is already advised to the future customer. We also want quality customers, right?

PS - I also have no PW# cert at all .... but have 2 pieces of paper that kinda say I qualified in E&E or something like that before. Oh, and I have an air cond installation and servicing cert achieved a few months back.... but still only doing friends and family air conds for now. Not ready to do commercially yet