Glass Tube Fuse Identification

[Tim Griffin]

Hi all;

I have a glass tube fuse with the markings 250V 3/3 1A on it.

Could someone enlighten me as to what the "3/3" designation means?

Many thanks,
Tim

 

[shrtrnd]

I don't have the information at my fingertips, but it will designate the physical size of the fuse.
There are a lot of different physical packages for fuses, and that is supposed to identify the type you have.

 

[Tim Griffin]

Ah, okay. Is there a way I know whether the fuse is a fast-blow or slow-blow fuse?

Tim

 

[shrtrnd]

Have you got a manufacturer logo on the fuse? The Littelfuse or Bussmann logo, or whomever made it?
That'll tell you exactly were to look for what the '3/3' denotes.
In simple terms, (that may not always hold true?):
A fast blow fuse is a single element, one, fine-wire element ( in a 1 amp fuse).
A slo-blo fuse will be a wire wrapped around a ceramic element (to take the heat, allowing time for a slower blow), or could be a spring-loaded element with many different appearances, depending on mfgr; or a variety of
other appearances depending on who made it.