Residential 3 Phase Wiring Help

Thread Starter

Sp@ceR

Joined Mar 11, 2018
50
I live at Malaysia where our main supply is running at 220-240V 50Hz. Bought a new house that comes with 3 phase wiring where my previous home is single phase. Below is part of the distribution board:
CHINT.jpg
I don't quite how the rating works in this case because I'm replacing some components (3 pole switch to MCCB, RCCB and RCBO to ABB brand):
1. 415V at the 3 pole switch refers to phase-to-phase voltage(R-Y, Y-B, R-B) so phase-to-neutral voltage will be somewhere around 230V(415/sqrt3) right?
2. 63A refers to the maximum carrying current for each phase or the total current for three phases shall not exceed 63A?
3. The RCD will not trip if current rating is exceeded because it will only detect current and earth leakage. In this case what does the current rating 63A means?

Ps: Our national electrical wiring guide states that main switch should be lesser than RCD. For example: 60A for main switch, RCD 63A. I wonder if I use a 75A MCCB as main so I will burn my 63A RCD? The RCD shown above is for lighting.

The overall wiring following national wiring guide:
3 phase.png

4. A 2 pole RCBO(for water heater) and 1P+N are they the same? With a 2 pole there's no neutral marking on wither terminal.

I have attached wiring guide. Don't be surprised it's 2008 Edition. Literally the same thing since then till now.


Any help is appreciated.
 

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Thread Starter

Sp@ceR

Joined Mar 11, 2018
50
Hope others will chime in

Exactly I was wondering if RCCB does not offer overload protection then does the rating referring to. Contact rating perhaps?
 

Dodgydave

Joined Jun 22, 2012
9,910
63A on any phase will cause it to trip, the Blue Bar connects the 3 breakers together.

The RCD is a 100mA Earth sensor trip time less than 100milli Sec,, the Orange T button is for testing, the 63A is the Maximum current on Each Phase.
 

MaxHeadRoom

Joined Jul 18, 2013
22,308
Now the question for current rating continues...

I thought that had been answered?
63A rating for each phase.
3 phase you do not see 63a simultaneously on all three phases at once!
If it doesn not recognize (trip) on O.C. then you also need a suitable 3ph breaker. or fusing.
Max.
 

Thread Starter

Sp@ceR

Joined Mar 11, 2018
50
Here's something I come across yesterday, an old stock Eaton MCB. In Malaysia, our MCB is typically DIN rail mount with 2 screws, running the same as UK electrical system. The Eaton breaker has only one screw. My guess the top is busbar connection and screw for load. However I couldn't figure out what type of rail mounting it uses. Any idea guys?
 

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Thread Starter

Sp@ceR

Joined Mar 11, 2018
50
The mounting rail is not sold separately? I guess this is used in US electrical systems. A friend told me this was used in local airport long time ago, which is really weird.
 

Thread Starter

Sp@ceR

Joined Mar 11, 2018
50
I encountered an incident just now. I was rewiring the LED light loops for my room, I accidentally touched the neutral wire and the RCD tripped. Yes, the one shown in the first post (NL1-63). I did not feel any shock but was surprised. After the power restored I tried to grab that neutral wire which was suspended somewhere on the ceiling. It accidentally touched the metallic structure of ceiling and again tripped the RCD.

Could it be a case of 3 phase unbalanced and current flowing through the neutral wire?

Ps: I have tested neutral with a test pen before and no current detected. Maybe a very small amount of current went undetected? Presumably less than 10mA? Last month I had the same case which I thought was caused by live current leakage.
 

Thread Starter

Sp@ceR

Joined Mar 11, 2018
50
The minor amount of potential would not likely show on your test pen, particularly if it is of the neon variety.
Max.
I thought that as well. Non contact voltage tester should be more accurate?

I think of switching off the circuit's relative MCB but RCD will still trip as it will still detect current leakage through ground right?
 
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