Fuse Ratings
Physics: AQA GCSE Higher, topic 2.4.7
Fuse Ratings and Circuit Breaker Settings
Fuses and Circuit Breakers must be chosen correctly to allow correct function.
Fuse ratings
- Fuse ratings tell us the level where a fuse will begin to melt. The fuse chosen should have a value just above the normal current that an electrical appliance uses.
- For example, if the operating current is 3.9 A, and fuses with values of 3 A, 5 A or 13 A are available, the most suitable fuse is the 5 A fuse.
Test yourself on Fuse Ratings
Why is a 13 A fuse wrong to use for an appliance with a 3.9 A operating current?
Which fuse should you use for an appliance with an operating current of 6.5A?
What do you need to know to select an appropriate fuse for a kettle?