see my observations as per the previous post above, it should be a RCD, pending confirmation from electrical engineers

This post has been edited by lowyat101: Sep 14 2023, 01:05 PM

ok found this online, maybe it explains why the manufacturer is still putting the wording ELCB on it while it's actually an RCD

A good indicator that an instant water heater is using a Mechanical RCD instead of an Electronic RCD is that Mechanical RCDs come with a lever, while Electronic RCDs are button activated, as mentioned by @lowyat101 and @Zot.

Some Panasonic models have an RCD button that when pressed, a lever will pop out. Those are considered Mechanical RCD too, not Electronic RCD.

I think only a few brands are using Mechanical RCDs, including
i. All PANASONIC models, eg. their newest model U-Series ( Lazada / Shopee )
ii. Some JOVEN models, the ones with RCD lever not RCD button, eg. the one shared by @lowyat101, SC33 Series ( Lazada / Shopee )
iii. Some CENTON models, the ones with RCD lever not RCD button, eg. Vintage Series ( Lazada / Shopee )





@lowyat101 are u referring to this section of the ST guideline? If yes, it is referring to RCD requirement OUTSIDE and not part of the instant water heater, while the picture shared by @goolie is the internal RCD inside the water heater. Requirement for the external RCD for water heater connection is 10mA as stated in the ST guideline, while internal RCD inside the water heater only requires 15mA.



Not quite right. If I am correct, majority of the SIRIM certified instant water heaters in Malaysia are using 15mA internal RCD, including PANASONIC, ALPHA, CENTON, and many more. I think only JOVEN is using 10mA internal RCD. U can actually open up the instant water heater cover and check on the RCD spec.

This post has been edited by Selene Yeo: Dec 14 2024, 10:14 PM

I see, didn't check through the ST guide in details so not aware of the 15mA requirement

But logically, if upstream protection is more sensitive than downstream then it looks like the downstream one will never get to work, unless they are of different mechanism. Maybe someone familiar with this can share some info for our knowledge

Hard to tell from picture. Perhaps it is not wired properly

Originally the ELCB is voltage triggered device. Once current flow in earth circuitry, it will produce the voltage to trigger trip mechanism in ELCB. Later current triggered ELCB was developed. So, there are two types of ELCB, voltage and current triggered ELCB. The current one is renamed as RCCB or RCD.

However I doubt it is an RCD here.

However Pana says they only have ELB not RCD.
https://eng-au.faq.panasonic.com/app/answer...what-is-rcd-%3F

Ultimately I don't trust anything in bathroom wet area, all the humidity etc for my "safety belt".
I will still strongly recommend having a proper RCD (VI type) fitted at DB box

10mA RCD, VI type
[ABB]
https://shopee.com.my/ABB-RCCB-ELCB-F202-AC...113.10546714691

[or the Hager equivalent]
https://shopee.com.my/HAGER-CC225B-25A-2-PO...9918.9413541871?

Schneider one not sure whether it is the VI or VD type. Because the shopee mall one never write the P/N, unable to tell.
VI= Voltage independent Residual current tripping technology

and if no space in DB box, the next best is to have 10mA RCBO fitted.

https://shopee.com.my/-EZ9D16625-Schneider-...4397.8516252845

Because whatever inside the WH clearly did not protect said instances from happening
1. https://www.nst.com.my/news/nation/2020/08/...e-electrocution

2. https://www.channelnewsasia.com/singapore/e...d-wires-2551426

in this case cables are badly burnt
so when you have a voltage-dependent RCD it may fail to operate
however, having any 10mA RCD fitted at DB box is still much better than no 10mA RCD at all.

This post has been edited by ceo684: Sep 14 2023, 02:28 PM

The house RCD has higher current trigger level to prevent false trigger due to accumulated leakage current in appliances. TNB guidelines shows 2 RCDs:
1) 100mA trip current for wires to lighting and dedicated power outlets such as for air-cond, water heater, etc.
2) 30mA tripp current for power outlets such as 13A sockets for universal use.

As for the water heater, another 10mA RCD is recommended to be install for each water heater..

For me either ELCB or RCD, both can be unsafe. Most importantly is to regularly check if they function properly. The ELCB depends on house grounding. Over years the house grounding can fail due to corrosion perhaps. There RCD can also fail to trip due to malfunctioned.

In water heater electrocution, I read that 100% is due to using conductive hose with conductive shower head, which is basically metal. Nowadays all comes with rubber/silicone hose. Many say ELCB not safe but for me, it is still okay. WH body is plastic. Metal part inside the WH which is the heater itself is grounded. If there is shorted, the ELCB is triggered. The RCD operates in different way to prevent shock which is also no problem. However, normal RCD cannot detect faulty unit. Say the WH runs at 3kW, but when the current goes to 5kW it will not trip RCD because the supply and return currents are still balance . Once the current goes over the MCB, then the MCB in DB box will trip. So, still safe to some extend.

Like I said the most important thing to ensure that those safety device performed normally with regular testing.

Fixed. That is based on Msia's ER 1994 regulations which is outdated AF


which the MS1979 COP references as well


meanwhile in SG 2023..
 Circular_RD_E01_2023_ELISE.pdf ( 247.6k ) Number of downloads: 8


This post has been edited by ceo684: Sep 14 2023, 04:15 PM