Fuse Ratings Explained

16 January 2017  |  AdrianR

Typical style capped glass fuse 

Modern fuses used in automotive and domestic applications now have (and should have) standardisation for fuse identification. Current fuses in production standardise the displayed rating for "Continuous use", but in some cases, in particular glass fuses, the rating on the fuse cap can still be marked with a "Blow rating" in Amperage by manufacturers. Which often leads to confusion even within the electrical trade.



Because a fuse is there to protect the circuit components and cables from current overloading, for safety reasons and component cost, it's important to note that; 

Continuous rating for fuses means they should blow at the Amperage when the circuit is always on or plugged in.
Blow rating for fuses means that the circuit is intermittent (On/Off), and the fuse heats up before blowing.

Before replacing old glass fuses, it's always recommended that you check your equipment manual or supplier's website documentation before replacing fuses to determine precisely which fuse rating you require.


  Start browsing for your Auto Electrical parts: Here.

NATO NCAGE Supplier Code: U07T3  |  Need help? Email us: sales1@arc-components.com
UK ISO9001 Auto Electrical Parts Specialists