WH will require minimum 4 sq mm cable with RCCB 10ma protection - this is Suruhanjaya Tenaga rule!

Your water heater if on at full blast (max temperature) will melt the cable and the 13A socket plug.

If you insist to use back the same wire you must minimally install the 10ma RCCB and make sure your RCCB is 16A at maximum otherwise your cable will melt and catch fire - the cons is you should not on your WH at max temperature because your breaker will trip to protect your wire from overheating.

Still 13A socket point should not be used here, go buy the one specialized for WH. This is a matter of life and death though have fun arguing with some half-past-six electricians that will suggest with you to go with 100mA RCCB or even 300mA to prevent tripping - 30mA may be the best advice they could give HOWEVER 10mA is A MUST by ST rule!

Do not forget - Insurance might choose not to compensate if they find that the accidents/fire was caused by wiring setup that did not follow the right specification!

Good to hear that!

1 month ago 300 Mat Rempits illegally gathered in huge group and raced in Penang but just less than 2% died - supposed rempiting is 98% safe. 😂

Yes, just make sure the professional is a real professional with licensed and advise according to guideline.

Life is cheap anyway and you are not alone actually, as I can see many houses are not setup according to specs and regulation.

The othet suggestion I have which are cheaper and do not require major rework would be changing the socket to the WH type 15A at least, and before the switch just install a dedicated RCCB 10ma before your 20A switch which should give you a good protection already.

Yeap - if you can invest in this product is even better - to replace the 15A plug.



This post has been edited by davidlow7: Aug 24 2022, 12:02 AM

You are welcome.

It doesn't matter... but I would recommend the 1st place just before the switch (outside your bathroom with the on-off switch together) - it would work to track the current movement along the circuits already. I don't recommend putting it in the wet area (inside bathroom especially) so I would not recommend option 2 which many would usually put beside it. It is not an IP65 66 or whatever IP rated device.

True.
I spec everything for my house and just ask them to name the price - things that I do not agree I will source my own part. For example the SPD RM500 ABB, he charged me rm1000+ for same thing. Not sure if his supplier gave him the correct price though.

Usually I am still okay if price is just the issue so at least we can directly go into negotiating - but what annoys me the most is the issue with their knowledge .. saying no such thing of 10ma for water heater and saying RCBO does not exist in Malaysia.


You can but if can please ensure it is protected from water splash - buy a transparent cover probably that covers it well. Make a habit to test it monthly for safety purpose.

If your setup is 2.5mm and using on good brand like MEGA or Caramay is okay - but anyway if not, and become too much of a hassle to change then you must make sure your setup along the circuit must be correct and right sized - 16A/20A MCB max.... - 2.5mm wire must follow the 2.5mm way of setup then would be good.

This post has been edited by davidlow7: Aug 25 2022, 10:35 AM

The water heater built-in ELCB does not to protect human, it is only for the equipment. This had been highlighted numerously by our sifu @ceo684 which is correct so you are left with only the main RCCB to protect you in case of any leakage outside the water heater ..and usually the main RCCB at 100mA would not be able to protect you from death... at 30mA you would stand a chance to survive but not one without severe pain and injuriy to your body.

This is also shared by Showertec
This post has been edited by davidlow7: Aug 25 2022, 11:16 AM

There should be an earth wire that is connected directly to your DB Earth Busbar - so there will be 2 options depending on your setup.

Setup 1:
if you are using a 20A switch without another 3pin(round)socket --> then this earth wire will connect to your WH unit directly.

Setup 2:
If you are using a 20A switch + the 3pin (round) socket then this earth wire from DB will connect to your the socket in "E", while the L+N will come from your 20A switch.

This post has been edited by davidlow7: Aug 25 2022, 11:40 AM

I can understand the point you are trying to make. especially for a more advanced user like yourself, but in reality things are always never going to be straight forward that's why I would advised against sending a message that the ELCB in each WH unit are safe and designed to protect human like exactly in RCCB.

Ability to understand the technicality of everything would help yourself in making an informed decision, but when it goes to the MASS then it is about making sure it becomes practical for people to understand in the most simplest manner possible.

You would never know what are inside certain manufacturers' units and the timeline that bought also came with it, and also the customization by users that would happen over time, such as the use of stainless steel rain shower to replace the hose set. Some people would be using very old units that might have different components in it - the truth is no one can confirms unless a test on each model would be examined - which is of course not possible.

What we know is - For sure following the setup for a dedicated RCCB 10ma would eliminate the uncertainties around.

This post has been edited by davidlow7: Aug 25 2022, 12:12 PM

This just popped into my mind this afternoon thinking about those homestay people are going to rent for holiday! Especially in places like Cameron Highland where WH is a must!

For a 3300w power-rated oven, 1.5 sq mm cable is questionable by a mile!

Secondly, I will not use a 2.5 sq mm wire for a power-hungry appliances like oven, I would go for 4mm as you are going to run your oven for a long duration. You are probably testing its limit - a water heater at around 1A to 2A higher usually runs at a much shorter duration is already advisable to go with 4 sq mm wire. Regardless of the wire size, you need to invest in a better quality wire so it can lasts you long - having SIRIM should be the bare minimum

This post has been edited by davidlow7: Aug 26 2022, 09:51 AM

Using non-sirim product is against the law - you can try raise a complaint to ST if you want but make sure you do your homework and have the necessary documents/information - and also if you think it is worth to go through the "process". It is completely up to you... that's why there is always a phrase of "prevention is better than cure".

Using a non Sirim cable you would expect the cable quality is at least 30% bad (just cincai plucking from the air, but who knows may even be worst). There are videos in YouTube which show you in true practical test - just search it.


Sad to say this is the Malaysia "norm".

Judging by my own experience going to 10 electrical shops giving me bullshit theory (RCBO no such thing, 30mA water heater, 100ma for socket etc) - I would say that this is so normal when wireman decide to also follow the "norm", partly also driven by customers who only wanted cheap.

As long as it is a 10ma maximum sensitivity that is a good one.

Suggest to create a new thread for a new topic, but you might want to do a search if there is already an existing thread about the topic which you can leverage on.