Most welcome. Am operating mains RCD at 30mA (0.03A) whole house sorry for blur pic.

a. Current models got datasheet, basically either ABB/Hager current model [not listed as discontinued] will be fine.

b.Yes, Electricity Regulations 1994, MS 1979:2007 and MS1979:2015 for protection of 13A sockets, and since this is the tightest regulation, it only makes sense to have a 30mA fitted for whole hse. Complete protection.

Would you drive at high speed without a seatbelt on?

c. To add on, not just mains 30mA [whole house] but you should get a 10mA RCD per each water heater fitted too.
I'll be more afraid of what happens in page 30 of
https://www.st.gov.my/en/contents/publicati...r%20Systems.pdf
rather than nuisance trip.

FWIW everywhere in AU, SG all use 30mA. I also use 30mA. Life protection more important. Good [top-tier] modern RCD hardly nuisance trip.

See attachment pg 21
Those who know will spec out personal homes to be as tight tolerance as possible, despite high cost [sensitive RCDs cost more], for lives of loved ones are priceless - can't sleep at night if we did a half-assed con job;
those who cincai undercut job of coz spec as loose/cheap as possible to avoid rework calls [since less sensitive RCDs are cheap and trip way lesser]

An RCCB does not trip on overcurrent. You should be running
Incoming power -> 16 A MCB -> This 25 A, 10 mA RCCB -> Water heater,
so that the MCB trips if more than 16 A flows, and the RCCB trips if there is a leakage approaching 10 mA.

Only an RCBO is like a combination of MCB + RCCB, and will trip if overcurrent or leakage current.

Can't comment on the brand, sorry.

Can't find anything related to the brand hence "no comment". The trademark is super generic nothing shows up on a bing/google search for "safety SRA2 RCCB"  :confused:

Follow stormer.lyn post above is correct.
Personally, if own house I'd spec in only ABB/Hager because "you get what you pay for" also applies to components - you get VI type RCD; anything cheaper tend to be VD type RCD.

So should I change to RCBO
--mostly boils down to space question only "DB box can fit the 10mA RCD [2module width] or not; since can fit should be no problem
--RCBO = RCD+MCB [like washer/dryer two in one - vs a washer+a standalone dryer]

Any brand with 16A RCCD or RCBO with 0.01mA for WH and 63A/0.03mA.
--ABB/Hager   

Can provide model no. for the VI type RCCD. Appreciate

based on ur pics ur on single phase.

mains 63A/0.03A [30mA]
-- ABB RCCB/ELCB FH202 AC-63/0.03 (30mA) | 2 POLE (2P)
-- Hager CD263B = 63A 2P 30mA; or CDA263U

WH 10mA RCD [need to pair with 16A MCB]
-- ABB RCCB/ELCB F202 AC-25/0.01 (10mA) IEC | 2 POLE (2P)
-- HAGER CC225B 2 Pole ELCB / RCCB 25A 10mA

Incoming power -> New(Safety) 25 A, 10 mA RCCB -> Water heater, Is this OK?

Cannot standalone RCCB.
RCCB must pair with a 16A MCB.

Excellent. Hope the electrician willing to change a better/reputable  brand of RCCD.

Why do you still want to go for this "safety" brand? Is it not obvious to you that it is cap ayam? If you feel that you and your family's life is not worth so much to get Hager/ABB, then at least get Maxguard which is cheap and known to be "decent".

If on the other hand if your electrician insist on using this brand, then just change to another electrician. Or go and buy yourself and get a better electrician to install.

My comments may seem harsh, but you made the effort to come to a forum to ask questions and people gave you good answers but it is mind-boggling that you still choose to be ignorant.

not all electrical shops carries them cause hager rccb10ma not cheap.
where are you staying?

Shopee got many electrical stores selling online (CPE, KJE, Edaran)

My god, really have to spoonfeed ur electrician.