There is a leak in your wiring.

Hopefully you have had a 10mA dedicated RCCB with its dedicated wiring installed for the water heater only, as it is crucial in saving lives.

ELCB from your heater will not detect leakage OUTSIDE the WH so the RCCB is important.

There's a latest guideline from ST
https://www.st.gov.my/en/contents/files/dow...N_DOMESTIK1.pdf

I used the same unfortunately those jobs seem to be subbed out to others, where sometimes I don't feel confident when they answered something incorrectly.

Well, same issue I faced..

They insisted water heater uses 30mA and when I said ST rule since 1994 is also there already he looked at me and insisted "no such thing ever!"

If you still worry of easily trip (despite the good brands like ABB, Hager won't unless it is a life-threatening leak) then you can continue with 100mA for your lighting and fan, since human are usually not exposed to it. Keep the 30mA maximum for your plug points, and 10mA for water heater.

Bear in mind, you should in fact ensure your steel roof/steel-type awnings are grounded as well (a green wire to connect to your DB busbar directly) for safety - otherwise ((when there is a leak) anyone who climbs the roof to fix/repair something might get electrocuted to death since your lighting/fan RCCB sensitivity is only at 100mA. This also ST requirement actually.
It would be a miracle if people who install awning at his house would get an electrician to help pull a green wire connect to your earth busbar, whilst the awning are fitted with wired lamps/fans.

I think the outcome is probably same in most cases - this is a known trend in Malaysia even by many main cons who do house renovation would tell the same that most of them on "shared" licenses.

This allows some of the licensed and good ones charging at superb high price, which might be ok from safety point of view but they are usually reluctant in taking a one-off job - they are more interested in big project like 50k for whole house wiring.

30mA RCCB should be the one to go for in replacing the 100mA, in fact I agree it should be for today's standard.
What I meant was the minimum is then to follow ST guideline, as last resort.

I think government had probably not enforcing this in the guideline because factoring the implementations nationwide would be a hassle due to lack of control and complexity but as user, we don't depend on government to protect ourselves.

Here you go mate

https://www.st.gov.my/en/contents/files/dow...N_DOMESTIK1.pdf



This post has been edited by davidlow7: Aug 12 2022, 10:20 PM

Yes but I think the issue we have in Malaysia is enforcement... You can see many electrical shops also selling DB box with 300mA rccb for domestic use. Wiremen taking contracts are mostly non-licensed whilst licensed ones simply charge with no control.

My house wireman luckily is really a knowledgeable person when I asked him to get ready earth wire connected to busbar for my future awning - he said "Singapore standard is like that" - by Singapore standard it does not mean just the guideline but also the enforcement!

I don't have his contact, but only my main con's contact so you might not be getting the 1st hand price.... I am also waiting for the chance to get his