Just a question.   
your DB box is already correct    with   the    EPS switch fuse . 

what make you want to change  to   mcb  ?    ( it is not wrong to change. 

ok  there is no hurry for you to change this , just wait  till  one day you have electrician in your house , you and ask him change...

If your existing is the top photo, then the live goes in and out from it. The neutral from TNB will go straight to the RCCB.
If you change to the 2 pole version in the bottom picture, you should not leave the second slot empty (The slot on the right in your picture, without your red lines)
Take the neutral from the RCCB and poke into the second slot. And then from this dual pole take 2 wires and go to the RCCB.

Argh, sorry, logically the RCCB should be on the left, so the busbar can feed the MCBs

Edit to add this image from the internet

Get a electrician to help you if you are not sure.
Electric can kill you.

It is preferable to ensure that the RCD/MCB/isolator is from same brand. This way it will fit well when you install the busbar.
Also liability issue, if you fit proton engine into a honda MPV and using ECU from toyota, if the car blows up, I don't think insurance/mfg product liability will cover.

Also, for own house, preferably get the whole system from ABB/Hager/Schneider. These are reputable brands with easily 10-18 countries' certification.

The CE logo, to be honest is just suka suka self declaration [CE marking does not provide any specific information to the consumer. It is not a quality assurance declaration, it does not show evidence of third-party testing, and it should not be confused with any independent certification mark of the type issued by international or European notified test bodies.]
Seconded. When talking about main switch replacement you're dealing with live TNB feed of 230V at thousands of amps.
Just 0.05A is all that's needed to kill a person.

If working BEHIND the main switch isolator, that one is much safer since L and N are cut off from TNB safely. But to touch those live wires (since there is no isolator installed currently) it is a very risky thing, call an electrician.

haha, because recently read some articles about switch fuse and MCB, noticed that it is common practice to use 2P MCB as main switch.
thanks for your diagram. Appreciate it.
After watching some youtube videos I gained better illustration on this diagram.
It's true. Thanks for your warm advice.
Yes Sir, noted that. 

Hi all,

I'd like to ask regarding 63A 4P RCCB.
Below is a rough picture showing how the (3P+N) from the switch fuse connect to RCCB, as seen from my shop 3phase DB.


I was surprised to find out that the outgoing cable from 63A switch fuse connect to the lower part of RCCB. 

Usually it should be this way right ?  -->

Hope sifu could enlighten me.. 

It depends on the MCB spec.

When a MCB are marked “Line” and “Load,” the power supply conductors must be connected to the marked “Line.” These MCB cannot be reverse-fed. If “Line” and “Load” are not marked on MCB, the power supply conductors may be connected to either end. These devices are suitable for reverse-feed applications.


Those that say reversible line and load connections, or power supply connection=arbitrary then will work both ways.

Arbitrary doesnt mean random, but within reason, so if the line L from top, then line N also should be from top. So its not a license to have it LineL LoadN on top and LoadL LineN on bottom     

oh ! got such thing, now only know 
In the above bolded statement you mentioned about MCB, is RCCB also got such type whereby supply conductors may be connected to either end?
Sorry if I asked stupid question 

Usually RCD is direction specific and L/N specific. They will have a diagram 1 goes to 2, 3 goes to 4, that tells the line/load side, usually RCD is top fed.

So there is planning needed to ensure that the UUU and nnn sides all work in the right directions, right ordering sequence AND last but not least working with the physical limitation of the TNB line cables which in some cases are cut so super short that it won't even reach the end of the DB box, mine is fed from center (see the big red main switch). This causes the MCB to be top fed (but its ok because this series all arbitrary supply)

From your picture I see that one RCCB is fed from top, while another one is fed from bottom. Are these RCCBs reversible type?

See the diagram, in this case yes both ways also can for the RCD because 1/2 and 2/1 from the diagram.



As for the MCB,
S201 range is always top feed (1 Line goes to 2 Load).
This is an older batch pic curi from internet.


This is my actual pic of the MCB, sorry for potato camera.

haha, because recently read some articles about switch fuse and MCB, noticed that it is common practice to use 2P MCB as main switch.


thanks for your diagram. Appreciate it.
After watching some youtube videos I gained better illustration on this diagram.
It's true. Thanks for your warm advice.

yes true   sometimes   we have a choice  .
As you have already a switch fuse  installed  ,  i said just keep it.

Let s look at the  practical side.
there are   cases  that MCB  dont trip     due to various reasons . MCB can malfunction too.
how often do  you test your MCB ?  

The choice is still yours ..
my house  DB has a switch fuse 
I cannot find a good reason  to change it out to  a MCB .  can you  ?
i am thinking  about the risk and safety .

I really have no idea, sir. I am not good in electricity thing. I just noticed many new DB using 2P MCB as main switch hence asked this question.. If you tell me switch fuse is still a good thing, I will just let it stay there until it blows (don't know when haha).
By the way, would you spare some time to comment on my shop's 3phase DB posted above? Thank you Sir.

is your  concern  about the RCB device installation .
usually  RCD is top feed. 
what model  RCD  you have there ..?

Yes sir, I am particularly concerned about the reversely-fed RCCB and MCBs.
The RCCB model is CDL7463YC. Brand "Delixi".

Yesterday night I read one article, which says "if the RCD does not specify LINE and LOAD on the terminals, mean it can be reverse feed. If it does specify, then must follow accordingly". I am not sure this statement true or not.

lookin at the  circuit diagram  on the delixi  rcd ...its  top feed .  so no worries .  :thumbsup:

Are you facing  constant tripping  or very often trip ?

Yeah, circuit says top feed, but in actual it was bottom fed instead.
Could you see the Outgoing (from switch fuse) actually connect to the bottom of that RCD.

The previous Maxguard RCD did not trip when I pressed "T" . Hence the replacement. Asked an electrician to come and he had only this brand for 63A 4P 100mA RCD.  If 300mA, he has Maxguard. I chose 100mA.

i check the circuit diagram of the delixi  again  .  seems   you can  connect  top or bottom  .  no problem . 

the maxguard is  faulty  . 
possible can be  hit the lightning surge or the trip mechanism   mechanical  is jam .

Relieved to hear that.
I press T every month. Just early this month found out it won't trip.
Could you shed some light how to interpret the diagram,  particularly to check whether it can connect top or bottom?

Yesterday i studied many diagrams, only the ABB diagram labels 1/2 at top, 2/1 at bottom. Most other brands label 1 at top, 2 at bottom.

its best to check the manufacturer  installation guide .
when u buy  a RCD device  they put the guide  in the box. 

in this case they dont specify .  so top or bottom is OK.

the diagram is a guide  but  not  tell what is right regarding installation.

Unfortunately there is no guide/manual inside the box . What a cap ayam...