Thank you very much for the prompt advice! I shall engage an electrician soon.

My house was on single phase with 5 ac and 2 fridge. 5 years no issue

My house currently got 3 aircon (total 3.5hp), 3 water heater and 1 refrigerator. Plan to add another 1 unit (1hp). Attached my current house meter and db board (single phase electricity). Can my house support concurrent use of 4 airxon on the same times ( total 4.5 hp). The new aircon i plan to install now dont have aircon power point, maybe will loop from the power point socket inside the room (second floor room, db board in first floor, so quite expensive if get the wiring direct from db board). Any sifu can advise here?

This post has been edited by cyberkoh88: Dec 17 2016, 08:47 PM


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I have the same arrangement.. Its actually an aircon point and I added a few more 13A power sockets..

What's your monthly kWH usage ? 300 above or ..

Concurrent of 4 ac of yours is ok, but you have to aware of the situation if by any time switch on two of the water heater you will risk tripping the main fuse/burned the main fused (if older type of fused). Also make sure all the water heater and ac run independent circuit any sharing will risk burning the wires (worse your house)

Btw, your elcb limited to 40 amps, so is not wise to even switch on 4 ac & 2 water heater.

This post has been edited by weikee: Dec 18 2016, 11:41 AM

Just ask electrician to come over to inspect my house, he recommend me to change this 2 items (attached picture). Quote me RM400 for it,expensive?


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Electrician told me change to bigger fuse, can get it free from tnb?

The outside fuse can buy outside about 10-15 bucks for 63amps.

Changing fused allow you to have fuse to take higher load, but doesn't mean your original wiring can support it. Is better to confirm your wiring can support. From meter to house db box.

This post has been edited by weikee: Dec 18 2016, 07:23 PM

wah then the electrician charge me very high on this...just change outside meter fuse and some slot (2-3 slot in my db box as shown in my attachment). even told me very complicated and might take half day to change it...isit true?

Outside is simple, db box do need some skills.

ic, so you think RM400 should be reasonable price?

I won't be able give you actual answer, really depending the work done, material used and his workmanship.

All the time you use lay man terms..

You don't know better to keep quiet then to keep showing how ignorant you are..

Say something technical please..

Its a bit expensive..

- He wanted to replace the old cutout fuse (next to the Tenaga KWH meter) and Neutral link just because its old. I would too ( Those are rm30 (60A HRC fuse & fuse holder, rm5 for the Neutral link)
(15min job)

- Assuming he wanted to replace the rm30, 40A RCD (Maxguard) to match the load of the 60A DP Isolator (maxguard), (another 10min job)
Both components comply to the IEC regulation but thermal overload trip do not match each other..

Maxguard is a known electrical brand, its competitive and it has SIRIM/ST approval.. It has a presence in our local Malaysian market..

Those are just unscrew, component replacement and tighten back connections..

You can get another quotation if you want.. (A more reasonable rate would be around rm200)..

I'm not a contractor.. I'm an end user.. I work with competent electrical wireman/contractors..

I wish you to use the prevailing market rates and compare them to the actual service rates that are being carried out..

I wish you refer the the accepted quality approval bodies and the relevant codes for material rather than make general statements on sub par quality wire..

You mention sub par quality.. base on what standards? material/process/quality ? what is it?

You speak like a fool..

thanks bro for your update. anyway yesterday night do testing, open 3 heater and open 3 aircon (total 3.5HP) on the same time. after 10-15 minutes, cutout fuse (next to Tenage Meter) blow. my whole house no electricity. no choice, ask that electrician to come to do troubleshooting. just found out that my cutout fuse only 30A, no wonder blow. So ask him to change the cutout fuse to 100A. On the same time, requested him to change the 40A RCD (maxguard) to 100A and the 60A DP Isolator (maxguard) to 100A as well. And also ask him to change one of the MCB (20A) to 40A (because one of my room aircon power use water heater point to do looping, worry if open aircon/water heater on the same time, will overload, so as precaution ask him to change to 40A). All together quote me RM400, no choice, need to take it coz already ask him to settle my cutout fuse blow.

Electrical have rule to follow. Not what you want 100A this and that.

Max single phase is 60A. So everything must be content in 63A. Fuse or isolator. More than that, advise you to get 3phase.

Your single room heater and aircon share the same point is not recommend. Even you change the MB to 40A, your wire spec exceed the actual current running. Heater 3.6kw and aircon 1.5HP 1.2kw = 4.8kw. Your 2.5mm wire is running hot.

As a precaution, separate into 2 point with 2pcs MB is the proper way.

thanks bro for your advise. will consult again with the electrician on this matter. This electrician are the one that do all my house wiring renovation last time. He might know whether the wire he's using can sustain or not.

I think you better consult another electrician..

No competent will install a 100A HRC fuse in a residence. ST (Suruhanjaya Tenaga) whom regulates Tenaga Nasional and all electrical energy producers (EPP's) guidelines only recommend a 40/60A fuse for residential..

The function of a HRC (high rupture cartridge) fuse is to protect the wirings against maximum demand..

If your maximum demand is exceeded as what you have proofed then you are only recommended to max 60A single phase.. More than that 60A maximum demand you will need to pull in another phase and balance up the load ..

You run the risk of overloading your wiring and your protection devices..

Please remove that 100A and put in a 60A HRC..

The 100A cannot protect maximum demand and will start to burn cables if you so exceed it again.. You are seriously talking fire hazard now..

Go here and find the section for residential wiring guidelines .. http://www.st.gov.my/