Armoured Cable Technical Specifications
This blog creates an overview of the various sizes of armoured cable available and the technical specifications related to them.
- 1.5mm armoured cable is perfect for small, low power outdoor lighting circuits and to connect to small generators
- 2.5mm armoured cable is ideal for powering electric gates or high powered floodlights over a longer distance
- 4mm armoured cable would be great for powering a small shed or outhouse
The table below shows some of the information needed when deciding what cable is needed for a specific job.
Firstly the cable size in CSA this is how electrical cable is measured. In the second and third column we have the Reference method this is how the cable will be installed, for example, whether that be in a length of conduit in a wall or in free air, attached to cable tray etc. You should notice there is a vast difference in the current carrying capacity of the cable depending on which method is used.
Lastly we have volt drop the unit for this is MV/A/M, This is used in the equation below to work out the voltage drop over the entire run.
| Core Cross-sectional Area (mm²) | 1. REFERENCE METHOD C (CLIPPED DIRECT) Amps |
2. REFERENCE METHOD E (IN FREE AIR OR ON A PERFORATED CABLE TRAY, HORIZONTAL OR VERTICAL) Amps |
3. REFERENCE METHOD D (DIRECT IN GROUND OR IN DUCTING IN GROUND, IN OR AROUND IN BUILDINGS) Amps |
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| Two Core Cable Single Phase AC or DC | Three or 1 Four Core Cable Three-Phase AC | Two Core Cable Single-Phase AC or DC | Three or 1 Four Core Cable Three-Phase AC | Two Core Cable Single-Phase AC or DC | Three or 1 Four Core Cable Three-Phase AC | |
| 1.5 | 27 | 23 | 29 | 25 | 25 | 21 |
| 2.5 | 36 | 31 | 39 | 33 | 33 | 28 |
| 4 | 49 | 42 | 52 | 44 | 43 | 36 |
| 6 | 62 | 53 | 66 | 56 | 53 | 44 |
| 10 | 85 | 73 | 90 | 78 | 71 | 58 |
| 16 | 110 | 94 | 115 | 99 | 91 | 75 |
| 25 | 146 | 124 | 152 | 131 | 116 | 96 |
Cable Volt Drop Calculation for Armoured Cable
Vd = mV/A/m x I x Ib ÷ 1000
- mV/A/m = the voltage drop per metre per amp
- I = the length of the circuit conductor in metres
- Ib = the design current
The permissible voltage drop for low voltage 240V installations is 3% for lighting and 5% for other uses.
Further information and technical specifications for armoured cable
We have a dedicated page for each size of armoured cable please click the link to the size you need.
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