If you've read our article on Plug Safety, then you'll have a rough understanding of how to wire up your fuse safely to its plug. However, if you have all of your power supplies and lights and are still unsure about calculating the correct fuse Amp then please see the below guide.
In scientific terms: P = I X V (Power = Current x Voltage).
If we start with a common household item, let's say a vacuum cleaner, this can be quite high in Watts. If we were to take 1000W, for example, then we simply need to divide this by its voltage input (supply voltage), which typically would be 240V.
So, 1000/240 = 4.16. This would suggest, then, that a 4.16 Amp fuse would be acceptable. However, we must also allow for an additional 20% higher Amperage fuse, much like we would add to our LED Strip calculation when determining the correct Drivers. We would then suggest that a 5A fuse will be perfectly suitable.
Using this formula, we can now move on to LED Strips.
Let's go with a simple installation of a 5 metre strip, running at 14.4 Watts per Metre. We can calculate 5 x 14.4 = 72W. As before, we need to multiply by an additional 1.2 to give 86.4W. Now that we have the total amount of Watts required, we divide this by our 240V power supply:
86/240 = 0.358A. This mean that you will need at least 1A fuse (although up to 3A will be fine).