The purpose of 3phase is to able run more high current equipments concurrent and even load distribution. What is the point to have 3 phases and your internal not properly distributed? If you only have total of 10mcbs don't waste your money. Unless all your mcb are to power water heater/ac

1) Upgrade of the fuse from single to three phase, you will have to be through tnb or ask electric contractor to help.
2) you have to change the distribution board mcb to 3 phase incoming and the bus bar to 3 phase.
3) no, you do not need to rewire the whole house.

Forgot, to say elcb have to be three phase for incoming. Specifications must comply to local authority.

This post has been edited by Noobl3t: May 6 2014, 04:59 PM

And the purpose of all these without increase number of mcb and power points? unless your house already have 20 - 30 mcbs if not serve no purpose for changing 3phase.

Hi hi,

Just a question on 3 phase. Can a house have 2 3 phase meter? I have an issue with load due to the high electrical usage and was told that 1 3 phase meter is not enough. Just wondering what can I do about it? Adding more DB boxes as opposed to having 2 3 phase meters?

Thanks

I answered based in his question. It's is dependent to his load usage. U can have 30 mcb, but u can still run it on single phase, dependent to load, e.g all lights.

If house try to arrange, big load mcb evenly on the phases

This post has been edited by Noobl3t: May 6 2014, 05:14 PM

Mind sharing the total cost incurred including breakdown for benefit of other members? TQVM

Nope, if the 3 phase wiring are done properly, you should not have much problem with it.
Only you have to worry if there's only 1 single phase run all the air conds, sure it will be high load on that particular phase
Usually you will have such problem when the wireman wants to make fast money

And served no purpose just replacing incoming from single to 3phass without knowing the load and evenly distribution of the incoming.except giving more deposite for tnb to keep and installation fees.

You running hotels? Big bungalow one meter enough. Say one phase you use 40amps you use all 3 phases is 120amps that is 27+kwatt. Not enough? You can max it to 60amps per phase.

Additional meter may only allow if it is commercial rate, I ask before when the contractor came change my analog meter, because 1-300kwh are subsidized and if you have more meter you are enjoying from 1-600kwh. Tnb and gov not stupid.

Maybe he is going to add multiple ac to his house? I don't know.

He asked whether he can change to 3 phase without rewiring, I answered accordingly. The answer is no, u don't have to, just be aware your incoming mcb, elcb and bus bar which require to be changed.

Total RM800 only, including constructor fee RM300 and TnB Application + Deposit Topup.
The rest will be your own internal cabling. This is is depend on your house electrical design already.

As I understand, our 3-phase voltage is 415v and single-phase voltage is 240v. Will there be any issue using single phase 240v appliances under 415v 3-phase? I have an electric motor rated at 380v, can I use it under 415v?

I know the deposit is higher and the meter is more expensive but it is only 1 time payment.

I think for household 1 phase go up to 63Amp

3 Phase wiring, does not mean you have to use 415v, Each phase is still 230. Unless you use all the 3 phase in the same equipment you equipment need to be build to support 3 phase and voltage of 400v.

In tnb supply, 240v is come from 415v.

You can't use 380v rate motor on 415v supply. Risk of burn the stator coil.

Now TNB is 230 / 400 It was made public many years back. Therefore our current will be higher. If not mistaken it allow variance of -6% - +10% The change is to inline with the international std.

This post has been edited by weikee: Jun 26 2014, 11:57 PM

hi anyone can recommend me contractor that does 3-phase tnb applications? much appreciated.

Hm let's say.

If I plan to install another 2 aircons in the house at a later time which will make it a total of 3 in the house. I would have to change to 3 phase?

But as far as I can see, a single bungalow has no problem running all 3 aircons on a single phase.

If the main fuse are 60A or higher rating, for sure single phase also enough.
But once your house caught fire, insurance won't pay you.