What Size Armoured Cable Do I Need For Outdoor Lights In House

What Size Armoured Cable Do I Need For Outdoor Lights In House?

When it comes to installing outdoor lights in your house, choosing the right size armoured cable is crucial for ensuring safety, reliability, and longevity. Selecting the appropriate cable size depends on several factors, including the power consumption of the lights, the distance from the power source, and the presence of underground obstacles. In this guide, we will explore the essential aspects to consider when determining the correct armoured cable size for your outdoor lighting needs.

Factors Influencing Cable Size Selection

The following factors play a significant role in determining the size of armoured cable required for outdoor lights:

Power Consumption: The wattage of the lights you intend to use will determine the current draw. Higher wattage lights require a larger cable size to handle the increased current.
Distance from Power Source: As the distance from the power source increases, the voltage drop along the cable becomes more pronounced. A larger cable size helps minimize voltage drop, ensuring adequate power supply to the lights.
Presence of Underground Obstacles: If you plan to bury the cable underground, obstacles such as rocks, roots, or other utilities may require a larger cable size to withstand potential damage.

Calculating Cable Size

To determine the appropriate armoured cable size, you can use the following formula:

Cable Size (mm²) = (Power (watts) x Distance (meters)) / (Voltage (volts) x Voltage Drop (%))

Note: The voltage drop is typically assumed to be 2% for outdoor lighting applications.

For example, if you plan to install 400W of outdoor lights at a distance of 20 meters from the power source, the required cable size calculation would be:

Cable Size (mm²) = (400W x 20m) / (240V x 0.02) = 16.67mm²

Rounding up to the nearest standard cable size, you would need a 16mm² armoured cable for this installation.

Armoured Cable Benefits

Armoured cables offer several advantages for outdoor lighting applications, including:

Protection: The metal armour provides robust protection against physical damage, moisture, and pests.
Reliability: Armoured cables are less susceptible to damage caused by bending or twisting, ensuring reliable power transmission.
Versatility: Armoured cables can be used for both underground and overhead installations, providing flexibility in cable routing.

Conclusion

Choosing the correct size armoured cable for outdoor lights is essential for safety and performance. By considering the power consumption, distance from the power source, and presence of underground obstacles, you can determine the appropriate cable size using the formula provided. Armoured cables offer numerous benefits, including protection, reliability, and versatility, making them an ideal choice for outdoor lighting installations.