Hello my 30 year old house is getting another air conditioning 1 HP.
Below are the followings specs of the AC and wiring.

Is it safe to use such thin wiring for AC with the distance of the wiring span about 8 m to the backdoor for the compressor and back into the room?
I'm not an Electrician. Wiring is done by Air Conditioning Installation Technicians.

The thickness of the cable is 2.5mm² they provided to me.





Updates:
Installed the Air Conditioning unit Already on 05-June.

06-June. It started to rain, and lightning comes, just realized the RCD will keep tripping and became more sensitive when lightning strikes.

Then a new discovery when I go Label each Circuit Breaker in the Electrical Box.
Found out that my new A/C is linked to another older A/C upstairs and other wiring outlets
So Basically no A/C in both rooms tonight. And turned off most of the unnecessary Electrical Appliances and try to Google Up another Electrician Tomorrow.

---------------------------------------------
Updates:
After reading Surahanjaya Tenaga Guide from 2008
http://ocw.ump.edu.my/pluginfile.php/11228...al%20Wiring.pdf

Realized that Air Conditions should have a 4 mm² wiring connected to 20A MCB
And my house RCD supposingly was a single 30/100 mA RCD by MaxGuard, but the technician swapped out to 300 mA MaxGuard



This post has been edited by iSean: Aug 6 2020, 01:35 AM


Attached thumbnail(s)

Self wiring?
Can use 2-3 cables for each if you worry.

2.5mm can. Using it at my office. Smaller AC can use 1.5mm but don't risk it.

I'm not a technician , I have no knowledge on the thickness on wiring 😂

From the look of the ST star label this is NOT an inverter aircon?
Means every time motor kick in is full current inrush coz no inverter = no soft start
Your wiring should be OK at 2.5mm2 COPPER diameter (not plastic diameter). However, it doesn't take a genius to recon the paper from mega kabel (a good brand) and wrapping it on cheapo china cables

Excerpt from ST

Detecting Sub-Standard Cables (DIY)
• Check labels and markings for size, type, manufacturer
name/logo and product standard
• Verify physical measurements against manufacturers’ data
• Estimate the cross-sectional area of conductor by physical
measurement i.e. area x number of wires
• Conduct a conductor d.c. resistance measurement to the
Standards

https://www.st.gov.my/ms/contents/presentat...NCES%202015.pdf

For your reference

http://www.ucable.com.my/substandardcables.html

http://www.ucable.com.my/thehowtocableguide.html

For engineering student reference (highly technical)

https://www.skmm.gov.my/skmmgovmy/files/att...ts/FTS_LFCW.pdf

This post has been edited by ceo684: Jun 4 2019, 11:23 PM

5Amps running with a conventional inductive compressor motor..

Using an undersized cable.. Trying to save money?

Any actual recommendation on Wire Diameter Thickness?
I'm not a certified Electrician with a Wiring Certificate. I didn't do the wiring job for my parents 30 year old house.
I suspect Air Conditioning Technicians also all unqualified to do electrical work cheap out on cables... They keep claiming cukup...
Now my RCD tripping like no tomorrow when rain / lightning comes today.

Anyone knows a Good Electrician ah?
I just found out my 30 year old housing wiring is fucked up.

When I realized on Circuit Breaker is connected to 2 x 1 hp A/C. (Old and New) + 2 Other Wall Outlets....

This post has been edited by iSean: Jun 6 2019, 11:17 PM

Sadly I have no idea how to differentiate now, since everything concealed behind plastic housing.
I'm not technical enough to do these.

Need to see trash can still have any bare wires they thrown out
To do the Resistance Test.
Just use Ohms Meter to test resistivity of the wire only?

This post has been edited by iSean: Jun 6 2019, 11:23 PM

Bro,
If possible get a licensed electrician to check your wiring.

The tripping of the RCD indicates an electric current leak from your wiring. It takes a time for the eletrician to try trouble shoot with an cable insulation tester then finally a RCD trip tester to repair/replace the bad circuit. Ask for a quote for the job if you feel that the eletrician might be overcharging you.

Not a wire resistance test which is only for circuit board repairs (with resistors/capacitors)

For a residential home you need wire insulation testing. You might try with mudah.my as they most likely be certified.

This post has been edited by Richard: Jun 7 2019, 01:16 AM

Well I'm just uni student hahaha. Well will try to let my parents know what to do. If they neglect my advice find any non trained technicians also no choice. 😂

But will check on Mudah see if it cheap or not

Just my opinion not qualified tech. Ur switch at db is sharing with other cannot hold load or the current switch is too low. Remember aircond installer mostly not a qualified elec tech

2.5mm is not thin leh. That is what they use to run cables inside your wall. That can take 3HP at least (up to 4800W max)...

FYI - 1HP = 750W

Thanks for feedback. Most likely need to get another Electrical Box and another fuse. My parents not willing to hire a certified electrician 😂

u r overloading ur mcb, u r connected ur old and new aircond on the same mcb, wire ur new aircond to a new mcb (usually developers provide additional mcb on ur main switch board. Check ur amp rating n use the correct mcb rating

This post has been edited by kohchuup: Jun 8 2019, 10:14 AM

Are they willing to risk the possibility and cost of losing a house or someone's life instead?

This post has been edited by halcyon27: Jun 8 2019, 10:36 AM

Overloading doesnt trip the RCD. Most likely you need to check each circuit with insulation tester. 2.5mm more than enough for 1HP Air Cond. Ask the electrician to check your earth rod too. This is called impedance test.

Well true also. Electricity is a silent killer 😂 I think I need to get more surge protector. For my electronics also.

Also I think my ask my neighbour who does housing wiring work to check I guess? Since he is back. I'm not sure he is qualified to do testing tho.

This post has been edited by iSean: Jun 8 2019, 12:04 PM

Source for certified electrician from kaodim app lah. Get some quotes first.

Remember you are paying for quality not for some unqualified joker (trust me, my 2nd hand house got idiot screw the socket screw on the PVC insulation - and not on the copper of the wire) when I open the socket up for old-age replacement. There are many ways to cut corners, one of them is to use fake or substandard cables.

There's an app for that?
Yeah will check pricing tho.

So Far my house electricity seems stable. I think the A/C burnt my washing machine.
I press the start button, the washing machine trip the whole house now...

Just to share,

An undersized cable will be a heater and adds a lot to your electricity bill..

On starting an induction motor draws 6 times the running amps and will damage switch contacts if not properly installed.

Thus do not only look at a motors running amps when sizing a cable or starting contact switches. It will wear out and adds to your electricity bill if done wrong.

Which one matters more? The cable running to the indoor unit or the cable running from indoor to outdoor?

Asking because my electrician pulled 2.5mm2 Caramay cable for use by the indoor but when the aircon installer came, they used a not well-known brand (though SIRIM approved) 2.5mm2 wire.

I compared and noticed the one the aircon installer used is thinner than the Caramay cable. Asked if they have other better cable but they said no.

Distance is around 2m from the indoor unit to the outdoor unit and it's a 2.5HP inverter aircon.

Not sure if i should be worried. Your thoughts?

This post has been edited by Cyberbullies: Aug 11 2019, 04:34 PM

The compressor motor does the heavier load currents amperes thus use the thicker size cable compare to the indoor fan unit.

Meaning to save money run the power cabling direct to the compressor then smaller control wires interconnect the controller board and compressor motor.

Same cabling structure as the car starter to understand i.e. direct battery to solenoid and starter motor.

This post has been edited by Richard: Aug 11 2019, 05:45 PM