Lighting & 13A SSO, see below vv




Usually if the cables are in good condition, i.e. not chewed by rats in the ceilings and
voltage test is consistent between L-N, and
insulation resistance pass megger test Uni-T megger
you may not need to replace the cables.

More often than not, for <2000 homes the sockets' backbox may need replacement if they're iron when new, are likely to be titanic rusty iron.
I replaced those rusty backboxes to the China spec 86x86mm ones like these: https://shopee.com.my/Atlectric-Internal-Bo...5267.6809104931
These will need a bag of M10 screws from the bolts and nuts store (the usual ones that come with switches do not fit), but small issue. These plastic boxes are deeper than the normal ones and will require a bit of chiseling to expand them but they're hard plastic, not the (since 1980s till now) local made soft plastic backboxes that deform just from the cement used to mount them in place.



Not required to call TNB if you're not messing with the meter. Things after the meter are homeowner responsibility.


Laz/Spee are usually general parts only, for unlisted parts the electrical supply stores can get, sometimes I even ask them to list and I'll buy it once its up.
This main switch is commonly known as main switch isolator. A fancy name for an "on-off switch" that cuts off power to Live phases + Neutral, if installed at the main incomer, your whole house can be safely ISOLATED (off grid) and safe to work on.


In residential, the 30mA is max tolerance for 13A SSO and 100mA for light circuits.
This is main RCCB/RCD. 300mA is NOT according to code. I uninstalled mine for a 30mA.


30mA, still got chance to survive (life protection).
100mA, 300mA...bye bye


RCD is a highly sensitive Income Tax agent, you cannot cheat them of taxes. If INCOME is this much then the OUTGOING taxes must match the income you earn, up to the tolerance level.

The RCD works on principal of current in = current out + some minor losses due to cable resistance. This is safe.
But when the Total current in on live phase(s) is much higher than Total current out on the neutral, we have a 2MDB situation (current CANNOT be missing that much beyond RCD tolerance), as current NOT returned on outgoing neutral is something very wrong (i.e. can mean leakage through humans), and it will trip because it is a fault condition.
High sensitivity 30mA (0.03A) better than mid sensitivity or low sensitivity RCDs (100mA aka 0.1A or 300ma or 0.3A) respectively.

In smaller places with tiny DB box for 3phase, the usual way is to have a 3 phase (one piece RCD) to protect everything.
--This is like a one-piece dress lah, once coffee spill you need to drop everything immediately (leave the meeting) and wash the whole thing.
--This is up to code but the risk is that if any (current imbalance) fault happen, it will trip of course, but whole house blackout.

For a bit more money it is also OK to do 3 pieces of single phase RCD, one ea for Red/Yellow/Blue phases.
--This is like wearing a business suit. Coffee spill on the blazer, you can just wash the blazer. The top and skirt still can continue to wear. Continue with meeting
--This is recommended by ST for "business continuity" since one phase has fault, the other two still work as normal.


This is a "total load" OCPD (overcurrent protective device) to make sure that all the combined loads in the little MCB's (think the little branches on a tree) do not overload the main tree trunk (the main trunk cable).
If the main tree trunk is overloaded, the last protection will be the TNB fuse next to the meter will blow.


Yes, WH RCD protection is just for current leakage (Income Tax agent specifically targeting your business) and
MCB gives you TreeBranch overload protection for short circuit.
Two separate functions and must go hand in hand.



Running current of the NON inverter Pana 2.5hp (2.5HP Standard Non-Inverter R32 Aircon CS-PN24VKH-1) taken as reference = 9.7A. 20A MCB will be sufficient (C20).
Running current of 1.5hp will be around 6A for modern aircons. C16 also more than enough actually.

Note: MCBs are sized to the cable size NOT the APPLIANCE. Its purpose is to trip before the (overloaded) cable gets too hot to start fires.
C curve MCBs are VERY forgiving stuff. Aircons nowadays have soft start and delay randomiser so not all 8 will come on at the exact same moment.



For ABB 6kA MCBs, is around 7.50-8.00 each. Hager MU (6kA) tend to be more expensive ~12.50 ea for some strange reason.
Lighting - Depending on how the lights are set up it is unlikely you will have 125pcs of 11W on just one circuit (i.e. 6A x 230V = 1380W). I personally prefer to use 6A for lighting circuits' MCBs since nowadays LEDs consume very little power.

13A SSO if heavy usage places like kitchen, living room, then can run dedicated circuit each. Per ST rules on radial circuit, how many final circuits needed at a minimum, and whether you need 2.5mm² / 4.0mm² will be guided by the floor area to be served:


DB box x 2 = 30 ways + 45 ways? (Should I go for plastic or metal DB box?)

Metal DB box are the ones specified US latest code. Plastic is still combustible. I'd use metal if possible.
Eaton 48 ways are also available (16x each row). EPS or GEM local made metal boxes also available.
The configuration of the box (2x16 or 1x27 for example) you buy may be limited by the physical wires length coming out of the wall (if you are not replacing the whole wiring if they're in good condition).



T2 SPD look like the pic in my post (ignore the video using RCD as SPD) https://forum.lowyat.net/index.php?showtopi...ost&p=100886222
IMO if you have frequent lightning storms in the area (some areas are quite prone) then it is good insurance as lightning surges can kill devices.



WH use 4mm² if pulling new wires as this is still the biggest or 2nd biggest power hungry device in the whole house.
AC 2.5mm² minimum
13A SSO 2.5mm² minimum (up to 20m² floor area); 4.0mm² (up to 50m² floor area). Kitchen ones if you wanna save one cable run (to use the double sockets with two heavy appliances on one LNE run) can use 4mm².
Built in oven 4.0mm² or better (can also run 6mm²) depending on the wattage of the oven. If it does NOT come with 13A plug from factory this need fixed installation OR high amp (32A) commando plug.



Many fake cables out in the market.. there are many ways to cut corners or fake certification.
MS 2112-3 + SIRIM QAS + cable size (how many mmsq) + mfg name will be embossed or lasered into the quality cables.
If im a mfg and my cables are subpar.. I'll prefer not to label them.. if anything catch fire don't find me pls..



If existing storage heater is connected via a quality 10mA RCD, as it is a highly sensitive device any fault also will trip (including imbalance due to shared neutral on WH circuit but its not due to faulty appliance) then yes I still dare to use. For preventive maintenance - may want to double check the tank condition for signs of internal corrosion just to be sure.

Pump normally if its working fine then no issue, usually pump motor failure to turn (if it jammed) will create Imax and overheat the motor itself (will be more likely to trigger MCB in this case).

This post has been edited by ceo684: May 11 2021, 02:33 AM

Sizing of the incomer & homeowner's main cables should match the TNB supply (either 10mm for 40A / 16mm for 63A) cables; or 25mm+ if you have 100A supply.
The amperage you can draw safely follows lowest common denominator i.e. the smallest cable.

Your DB components have to give the proper protection, i.e.
1. meet the same amperage rating where applicable (for MCBs/isolator); and
2. meet OR exceed (for RCD).

Moving the meter or incomer cable (parts related to TNB) better get TNB panel electrician for less hassle.

IMO, if you haven't moved in your stuff yet it is easier to replace wiring, once you have settled in you won't bother already

This post has been edited by ceo684: May 11 2021, 02:27 AM

Actually about time to consider replacing the bolts to SS type. Not very expensive at few bucks a piece.. for peace of mind because structurally alot of weight still supported by the rafters.
Wood rafter still usable if theres no termite history. Metal roof structures should be coated with "cooling aid paint" i.e. intumescent paint so in case of fire, the steel will not "buckle under heat" so easily.
Read more here: https://www.ifsecglobal.com/fire-protection...ire-protection/

SS bolts and nuts just cost around RM5-6 a pop for 1/2" size..as a price refernce. Best to replace like for like.
https://shopee.com.my/4%E5%88%86(1-2'&#...5689.4356684848

Most welcome Happy to help!

Yes switch disconnector = isolator.
The basic flow goes like this. Zero components are TNB side:

00. TNB to cutout fuse (Plan Z last resort overload protection for your lot).
0. Main cutout fuse to meter.
1. Meter tails to your DB box ("main incomer"), and starts at Main Switch Isolator (aka the ABB switch disconnector).
For smaller installations isolator is optional and this job is often loosely done by the whole house MCB.
The ABB SHD203/63 shown is 3-pole isolator that does NOT isolate the Neutral. For complete protection I recommend to use a 4-pole isolator (3P+N) i.e. SHD204/63 ABB 4P isolator that completely isolates the whole lot from the grid including the neutral. Since single phase isolator cut both 1P+N. This isolator function is to put a very safe roadblock that nothing can come in -or out- from your lot. It makes it safer for anyone working on the electricals.

2. Whole house 3-phase MCB ("tree trunk protection") so this protects your main incomer wiring from overload overheating. This will be sized according to main incomer cable size, 40A for 10mm cable, 63A for 16mm cable, 100A if 25mm cable (rare but not impossible). It is important to size against the tree trunk (cable size), otherwise it will not trip even if tree trunk on fire already..coz haven't reach the overload threshold of MCB.
--this can also be in the form of a MCCB (gardenia bread small size) but kinda waste space for same functionality, although the MCCB will be stronger withstand in case of short circuit, more for commercial/industrial use case.
--MCB work on the live wires (3P). It need not bother with neutral.
--Price wise ABB SH203-C63 3POLE 63A 6KA MCB about RM75.

3. Whole house RCD. In residential, code mandates:
High sensitivity 30mA for 13A sockets where there is higher risk (mistouch plug pins, or stuffing pens into the 13A live terminal).
Fixed apparatus lighting or big motors (dinosaur aircon) can be placed on Medium sensitivity 100mA tolerance RCD. A High sensitivity 30mA will also satisfy this requirement.

For your condo:
Low tolerance 300mA is "illegal" unless special purpose like you have a production line dodol stirring machine.
Recommended to use whole house 30mA. If certain fixed apparatus devices trip the 30mA they can be seconded to a 100mA.



1. At the minimum: Swap out the 300mA to a 30mA 4P RCD to be safe. 300mA is essentially "useless" in residential whether for code compliance or life protection. From the main MCB you have a 40A 3Phase supply.. which means the RCD can be a 40A 3P 30mA (not expensive for 40A for the condo).
Pricewise ABB RCDs tend to be more correctly priced than Hager, equivalent quality since both also made in EU (Italy/France). 4P 40A 30mA RCD ~115 (ABB) , ~175 (Hager).

2. The big blocks like whole house MCB and whole RCD are not really important to be same physical dimensions (same brand) as they are connected with pigtails (short wires, and in 1-1 independent relationship).
3. The small blocks (individual circuit MCBs) should ideally be all the same brand as they are all connected by a flat metal common busbar.
Why this is important: for the short ones you are risking intermittent contact (the busbar teeth are not that long). Loose connections cause fires.
Since (if) you're swapping the 300mA RCD out to a 30mA, might as well change all individual circuit MCBs one shot to the same brand.

More often than not whilst parking lots are drawn the same size, the length of different cars will never be the same.. kancils are short.. trucks are long.. how will a common bar connect the kancils properly?


Cables

Unfortunately no. Usually "you get what you pay for" as raw copper cannot be that cheap for some to price much lower.. making plastic heavy and copper tiny is the way to get 20-30% cost reduction. "Not my house syndrome"

Many of the elcheapo cables will fail vernier caliper/micrometer test.. if really go deep into it.

As a longtime Caramay cable user.. the first thing is.. Caramay cables emboss (not laser printing) their markings into the insulation.
On the other hand I see Eco cables are using laser printed markings.

From a certification standpoint (can't really see in the pic) if its MS2112-3 certified it should work-lah, but I doubt the statement of same factory.. the output is different.

From experience both Caramay and Mega Kabel have proven reliable

This post has been edited by ceo684: May 12 2021, 12:03 AM

Generally cables increased price by around 25-30% (since March 2021)
for 2.5mm Mega Kabel/Caramay used to be around 85, now its 120-125
for 4.0mm used to be around 136, now around 163 online

Since your work volume is quite a big sum, there are such things called double sockets that will make end user life easier (just pay the variation few bucks in parts pricing). It will not "overload the cables" at all under normal usage (whole circuit MCB protected). Singles are used for small jobs to earn the few bucks "per point"..if all installed double how to earn (since your job is a big job the contractor should be pound smart and not penny foolish)

This post has been edited by ceo684: May 12 2021, 10:39 PM

Ref. above diagram and also to the sections 3.4-3.5  ST_Guidelines_For_Electrical_Wiring_2008_Edition.pdf ( 427.2k ) Number of downloads: 41
:
13A SSO need a full set 2.5mm² LNE (3-wires) from DB into the socket.
"Looping" (connect from next door existing socket into a nearby new socket) is the radial diagram.

For lighting point, they are cheaper since the wire length is shorter and the cables are thinner at 1.5mm².
Earth is optional if not using those old type fluorescent tube with the magnetic brick choke, and is usually not fitted, but its alright to have it fitted.
Typically lights do not come with earth wire, but for the old fluorescent tube with magnetic brick choke, this choke is like a "transformer" that need to be bonded to earth, while the lamp casing is not required to be earthed. Modern LED tube does not use the old magnetic choke so no requirement under section 7.5.

Usually (in standard 1 light point 1 switch, no staircase switching) it is:
single wire L from DB box to the switch, from switch and end at light point.
single wire N starting from light point and return to DB box.



Bare channel usually refer to the "casing kosong" for tube lights. Casing kosong meaning NO starter and NO choke (since these dinosaurs are not required) - LED tubes do not need the dinosaur parts to work. A bare casing will be able to operate LED tubes perfectly, usually these casing kosong is described as for use with LED-only.



Yes. As per the diagram the only extra effort is that the box hole need to be hacked bigger, and you need the double socket with matching box. Itu sahaja.
Identical wiring effort as per single socket as there's only 3 holes to be wired.



Per my diagram.. technically 3 runs from DB box, able to individually control 3 different bulbs on a 3-gang switch (in any possible permutations of ABC on/off) are considered chargeable as 3 points.
If per your picture one light circuit to control 3 bulbs either ALL on/ALL off i.e. just add two wires to the left and right should not be charged as full price since its "looping" that short piece of wire.

Technically this will be branching out 8 lights from one light point. Something like Xmas lights, 100 little bulbs on a single run, but with the RF controller you can turn on each of those 100 little bulbs individually. However, you still need some short wiring from the central controller to the 8 lights (like spider legs).

This post has been edited by ceo684: May 13 2021, 11:14 PM

Most welcome

For the feature lights.. basically just branch out 2 more wires from where the 1 point is.
If my understanding is correct you just need the wires sticking out where the light should be unless you're going with the tube lights?
(this pic shows a light point, fan point c/w hook, and doorbell point out the wall) but essentially the core idea is a ready-to-hook-up point.



Sometimes.. if the main con not clear about what's going on, then the subcon may add in all the side dish upgrades which are not needed or totally don't make sense.
Bare channel basically means tube light casing, i.e. http://www.degindustrial.com/page/products...l/vegas-1l.aspx and are definitely not required for the 13A sockets..

This post has been edited by ceo684: May 13 2021, 11:36 PM

For T2 SPD this has specific placement i.e. after mains MCB and before mains RCD 30mA. SPD need overcurrent protection of MCB only.
It also has to be connected to all wires (L1,L2,L3 no issue if placed next to mains MCB; importantly is the N and E returns) as short as possible.

Just to heads up why we need a bit of slack in the DB box wiring (ability to reposition and reconfigure layout) coz stuffing in a 4-module SPD (three phase) will need that room to fit. If everything hangman tight this will be tricky.

For the RCCB/RCD selection is this correct? You may have swapped them around.
Lighting is something that is generally low risk as user don't touch often and its out of reach of small kids. 100mA for lighting because back then people used a lot of old flourescent with chokes that often trip high sensitivity RCD, so a medium sensitivity 100mA is allowed.

13A sockets and metal forks and curious kids are high risk and therefore it need 30mA.



Selection of either MCB or MCCB also depending on the available mounting type of the DB box itself.
MCB/MCCB usually only cut the 3P live wire. It does not isolate the neutral.
Hence, MCCB does not perform the role of isolator

Isolator (4P) cut all 3P+N so even if some idiota wire the wrong way down the road and sets the neutral as hot wire when you're working on the DB box, you can be assured the whole house is completely isolated off the grid safely.

Actually its a different market segment. It is not about saving the pennies but it has to be up to code so that it doesn't need further investigations for the near future.
I am also interested in why a 30mA whole house RCD is NOT doable in 2021.

My question is - What kind of domestic device leak so much >30mA, that a high sensitivity 30mA RCD always nuisance trip? Note: device trip as leaky device, not circuit wiring aka wrongly connecting shared neutral in to dedicated RCD (WH circuits).

If the devices are that leaky then the old kettle or old fridge is likely due for replacement anyway.
Nowadays, lighting also noone really install old magnetic choke flourescent lights - all LED drivers / LED tube.
Factory high bay sodium lights? Noone use this at home.
Old kettle element leaky, is time to replace the device.
Old fridge? I have a 1997 Mitsu still running. Never tripped 30mA.
Old water heater? I have 1997 National that needed direct LNE to 10mA. Never tripped. (Previously shared neutral problem that tripped its own 10mA).Never tripped 30mA when no 10mA/WH unit was fitted.
Old rusted toaster from decades ago?
Old Grundfos B&W TV?
Unapproved questionable devices?
Commercial 3 phase dodol mixer? Welding machine? This is not domestic 230V appliance.

My point is - I can retrofit a medium sensitivity 100mA if needed if there is a need to run dodol mixer at home;
But if everything (based on 2021) works fine on a high sensitivity 30mA RCD (single mains RCD) why are we settling for less protection AND wasting DB box space/customer money to buy 2nd RCD 100mA?

The code say for lighting/fan circuit and WH circuit (as secondary protection) maximum tolerance of up to 100mA, NOT exactly 100mA.
Hence, one top tier 30mA RCD already cover all the ST mandatory requirement.
I personally run 30mA as single mains RCD and do not experience nuisance trips.

This post has been edited by ceo684: May 30 2021, 02:15 AM

Post a picture of the DB box overall and closeup pic of the largest blocks, for better commentary.

Switches, 13A sockets, in standard white good brand like MK [or Hager if u like bigger switch] is about RM5 each, WH switches RM20/ea
These are cheap if you DIY.

For MCB parts wise roughly without seeing the DB (assuming its a usual double storey or condo, not a huge mansion bungalow) you will be looking at RM400-600 parts wise only for complete DB replacement with top tier components (ABB/Hager).

Note: Exclude labour.

Generally usable but get the electrician inspect for surprises.
Also shared neutral problems at water heater

Magic keyword:
Wireman need to
Possess PW1/2 cert for single phase,
Possess PW3/4 cert for 3ph

https://www.st.gov.my/en/web/general/details/99

Chargeman also can do but wont be cheap and u wont want to pay their fees in a residential setting

Generally there's two types of clients
One that emulates purchasing dept and goes for lowest bid. These usually end up with so many cut corner creative shortcuts I also kepala pusing
More reasonable one that dont really bother on pricing (but reasonable lah), as long as work done properly and right materials.

Yes, if originally no 10mA RCD fitted but water heater installed - chances are the neutral can be shared by champion contractor last time and it will require pulling direct new LNE from DB to be sure.

Its bonded to the metal casing.
Hence there is a need for earthing.
You do not want humans to be the path of least resistance. That's why there is an earth for light points.

Chop the cable and change the plug top?
But be aware 15A is unfused, and your MCB need to be properly sized.

If the appliance itself came with factory fitted 13A plug top then there is no reason to change the plug top type. You can replace with heavy duty bakelike MK 13A plug top.

⚠️ There is a duty of care on the mfg when the appliance is sold with 13A plug top it has to be within 13A load.

⚠️ If it doesn't come with a factory fitted plug top for some high power ovens exceeding 3000W, then it is not meant to be used on 13A sockets. However, appropriate methods of permanent installation such as isolator may be used.

This post has been edited by ceo684: Mar 23 2022, 01:44 AM