It is better for the heater to run the wiring separately. I not sure will this cause by the fridge.

You can try to run the fridge separately by another wall socket. For a yrs and see what happen.

You never heard people have such problem with MCB only for heater.

Glad you got the warranty for your HVAC system

installed RCBO by schneider electric after finding out about it during archidex previously

Just to share from ST's (Suruhanjaya Tenaga) recommendations, here are a few installation details to take note of:

1. Cable/Power Supply for water heater should only come directly from the house's Distribution Board (DB). This power supply source cannot be shared, 1 supply direct to only 1 heater, and not tapped from the Aircond's socket or any other wall socket points.

2. To account for voltage drop, the cable length from DB to heater should not exceed 50m.

3. There should be at least 2 Residual Current Detector installed for protection, 1 nos 100mA for the mains (from TNB) into your DB, 1 more nos 10mA for the outgoing supply from your DB to the water heater. For the 100mA RCD, this is shared for your entire house. For the 10mA RCD, it should be 1 per heater, as per item no.1.

4. The cable/conductor size should be a minimum of 4mm2 for most instant water heaters in Msia (<5.0kW). This means that if you are using a PVC 3core cable (those grey cable with 3 in 1), it should be of the '56/0.30' size.

5. The Protective Earth should be a single run (green cable) as much as possible, and direct to your DB's Earth. That means you should minimise any 'sambung' cables, or to share the Earth with other power socket points in your house.

6. Lastly, there should be a certain IP rating to the socket used inside your toilet to connect the power supply to your water heater.

Hope this helps. The water heater is actually a very dangerous appliance which many people are not aware of. If installed simply, it is actually a time-bomb. Do pass these tips on to whoever who may need it, whether it is a new installation or an existing installation which may need correcting. Many houseowners are told by their electrical contractors or wiremen that so and so installation is correct or suitable but it might not really be the case.

This post has been edited by Jane's: Aug 8 2019, 02:52 PM

can share about this?

more details on this schneider electric website
https://www.se.com/my/en/work/products/product-launch/rcbo/

thanks! will give this a look

Any idea where can I buy this box?

Where are you located?
Shopee got 10ma RCD


M using ABB 10ma 25A RCD for the 10mA leakage protection coupled with B16 MCB for the overload protection at 16A.
The RCD is not meant for overload protection - for that you need a MCB. In other words you cannot have the RCD as standalone.
This setup consumes 3 slots in the DIN rail.

RCBOs combine this into one package (leakage protection + overload protection) into one slot single unit but it costs more.



At full load max heat (3300W heater) it consumes 13.77A, just under the 16A capacity of the MCB (86%).
Cable is 2.5mm stiff wire installed by developer + 50cm short length of flexible 3 core Fajar Cable installed by me.

Do note that you might need to use a bigger MCB if you have a >3.3kW heater (nowadays seems like quite a lot of 3.6 / 4.8kW models)

This post has been edited by ceo684: Feb 13 2020, 02:14 AM

Actually I'm looking for the box instead and I'm located at PJ

U can try Camar Letrik (road behind 3 2 square leading to sea park)

I want to install water heater at my home but haven't install the external ELCB device as shown as above posts. Can I know where to get the external ELCB device and how much for it? How do you guys install it or ask the electrician come to your home to install?

Nowadays noone use ELCB (dinosaur liao).
Standard is using MCB+RCCB 10mA coz more economical but this usually takes up 3 slots total in DB
Atas solution is using RCBO (= MCB+RCCB in one slot), more compact, price also more atas

No requirement to place it immediately outside bathroom. Even Sharp manual also puts in DB box SharpWH Manual
This will make whole circuit protected rather than just the few feet inside bathroom.

You will need to connect the RCCB with both wires Live & Neutral of the WH circuit.
Also the L of WH need to be connected in-line with either 16A or 20A MCB depends on your wire size and WH wattage.


Should get a good brand 10mA 2-pole RCCB - ABB Hager Schneider - all which are available on pee pee.
ABB https://shopee.com.my/ABB-F202-25A-2P-10mA-...0848.2293410974
Hager https://shopee.com.my/HAGER-CC225B-25A-2-PO...0848.1118792384
Schneider https://www.lazada.com.my/products/schneide...1275352820.html
also loose cable (4mm min red/yellow/blue + black) of 1m length each to make the pigtails

Installed mine myself. https://forum.lowyat.net/topic/2954371/+308#
Beware of Live electricity. Isolate everything before starting job. Check test pen make sure its working (when live). Check with test pen after isolate to ensure no electricity.

Beware of overly cheap RCBOs in the market. Got fake products.
https://www.ecpowersystems.com/resources/ci...rcuit-breakers/

This post has been edited by ceo684: Feb 14 2020, 04:41 PM

Any recommendations on what kind of water heater to get? In particular, instant heaters