Fuse Marking

[Roger Lascelles]

I want to replace some fuses marked F10AL250V

These are 10A, 250V rated fuses. But what does the L mean ? Possibly LAG
as in time lag ?

thanks
Roger

 

[Don Pearce]

I want to replace some fuses marked F10AL250V

These are 10A, 250V rated fuses. But what does the L mean ? Possibly LAG
as in time lag ?

thanks
Roger

The F stands for fast acting
10A is for 10 Amps
L is for low breaking capacity (glass package)
250V is the rated voltage.

d

Pearce Consulting
http://www.pearce.uk.com

 

[Pooh Bear]

The F stands for fast acting
10A is for 10 Amps
L is for low breaking capacity (glass package)
250V is the rated voltage.

Indeed.

Just for the benefit of the OP, the prefix T means slow acting ( 'slo-blo' type
) as in T for time delay, although note that US and IEC fuse specs are quite
different in detail. H suffix means high breaking capacity ( > 35A IIRC ) and
may be in a ceramic package ( but not always ).

Graham

 

[Roger Lascelles]

Magic. Thank-you both for your help.

Roger

 

[Ross Herbert]

I want to replace some fuses marked F10AL250V

These are 10A, 250V rated fuses. But what does the L mean ? Possibly LAG
as in time lag ?

thanks
Roger

Roger, everything you might need to know about fuses. You can download
The Fuse Bible from here
http://www.swecheck.com.au/frames/download_index.html

 

[Terry Given]

Magic. Thank-you both for your help.

Roger

do you know about rupture current ratings? that is the maximum fault
current the fuse can interrupt (without arcing over and then blowing
itself to smithereens). For glass fuses, its bugger all. HRC = High
Rupture Current (80kA typ.). A new NZ house has a fault current of about
6kA, which explains how come techs find glass fuses all blown to shit.
And why microwaves have ceramic fuses, which absorb the fault current by
melting sand.

I had to use HRC fuses in a 48Vdc LED video screen I worked on. Each
module drew 55W at 48Vdc, but there were 2,000 of them fed from the one
telco PSU (100kW), which could happily drive 2kA into a dead short,
continuously. So I needed a fuse with a 10kA *DC* interrupt rating (a
lot harder than AC). I used a Bussman/Cooper ABC series 2A (10kA dc
rupture) fast-acting fuse in each psu, and a MDA series 30A (10kA dc
rupture) slow-acting fuse in each data/power distribution module (drives
12 psu's). why slow acting? couldnt get a fast 30A fuse with 10kA dc
interrupt rating. And the pcb silk-screen has "2A/10kA" written
underneath the fuse, in big letters.

Cheers
Terry