I do a lot of new wiring for my properties. Usually I just hire electrician or civil contractors to do wiring without much thought whether the wires they used are suitable or not in term of ampacity (the maximum current the conductor can carry continously).
Until one day, one electrician told me the wires that I used for my fan and lamps are too thin to carry the current. It could pose fire risks. This is eyes opener.
Few days after I got the advise, one of new wiring was overloaded. The wires inside were burnt.
So I did my own studies as a guidelines to me, so when I hire an electrician I would know whether the wires and the way they connect to the electric power is able to support or no the possible current usage.
Guidelines on Wires Size
This is a guidelines only better check with your trusted or certified electrician.
If the same wire use for fan, lamps, fridge etc, you must add all the amperes and from the derive the required wire cross sectional area.
Of course usually, electrician will put extra buffer for the wire size.
|Usage||Expected Power (Watts)||Expected Current (Ampere)||Expected Wire Size - Cross sectional area (mm2)||Advisable Connection Type|
|Ceiling Fan||75||0.3125||0.5||Direct / Plug|
|Aircond (1 HP)||750||3.125||1.5||Direct|
|Fridge (450L)||46||0.1917||0.5||Direct / Plug|
|Lamps||75||0.3125||0.5||Direct / Plug|
This is my own definition not electrician definition. There are two types of connection:-
- Use plug to existing plug point
- Tap direct into existing wires in plug point.
The maximum current is 13 ampere as the fuse can only handle up to that ampere.
Direct Loop to Existing Plug Point
This is better at maximum if not mistaken it is loop directly to existing cable of 2.5mm2 or supported maximum current of around 22 ampere.
What to Avoid For Wiring
For water heater, don’t use plug better use direct loop to existing wires. Especially water heater produces vapor that might cause short circuit and easily makes the wiring wear and tear faster.
What is Watt, Ampere & Volts?
Watt is power unit with formula as below:
Watt (W)= Amperage (A) x Voltage (V)
Analogy with water garden hose:-
Water come out from garden hose (watts) = Water volume (Amperage) x Water pressure (voltage)
Recommendation on Wire Size
Ligthing & Ceiling Fan: 1.5mm2 Aircond 1.5HP and below: 2.5mm2 Adding new plug / power point: 2.5mm2
Recommended Wiring Contractor
Below is my recommended wiring contractor for Shah Alam or Kota Damansara area.
Azworld Tech (Azrin) – 0 17-376 0530
- Appointment on time
- Expert and reasonable charging
|Wire Size - Cross sectional area (mm2)||Maximum Current (A)||Maximum Powers (Watts)|
|2.5||22||Can't find the information|
|4.0||30||Can't find the information|