Fast blow vs. slow blow fuse

A fast blow usually has an " F " designator before the value, whereas a slow blow or antisurge type usually carries a " T " designator, for " T " ime delay - F2.5A or T3.15A for instance. If you look really closely at the actual fuse element, you can usually get a good idea of the type. Some antisurge fuses are very obvious, having a spring at one end, or a spiral wound nature, which may be on a glass fibre string former. Some, however, look little different from a 'straight' type, the only giveaway being a tiny 'blob' in the middle of the wire.

Arfa

snipped-for-privacy@yahoo.com wrote in news:1170638081.632130.300050 @l53g2000cwa.googlegroups.com:

Most reliable way is to read the part number on the side of the fuse and look it up in the manufacturer's catalog.

For example, in the USA, MDL-7-1/2 is a 7.5 amp time-delay, AGC-7-1/2 is fast-acting.

It's worth pointing out that US fuses are different to the rest of the world.

You may also find international (IEC) fuses in US gear as described by Arfa.

Graham

Thanks all. My fuse is blown but element remaining does have a "blob" in middle. Marks are on 1 end is current / voltage 4a/125 on other is buss gmc ul csa and a "T in a rectangle." What's th "T"? Ideas on what type fuse? Thanks. FYI for a TV.

Looked on bussman site and found medium time delay. Tried a GMA fast acting in set and blew. Think I should get GMC or you think there's a ground condition. 1st fuse doesn't look bad...clear glass and alot of element left intack.

A time delay fuse is fitted so that it can withstand the inrush current at power up. A 'fast' fuse is not a valid replacement, and will blow for no other reason than that ... Fit a " T " rated type of the correct value ( 4 Amps ), and all should be well.

Arfa

Is this fuse in that Tv you were trying to fix?

If you're working on a TV I think you're in over your head if you don't know the difference between fast and slow blow fuses. I'm not trying to insult you, I'm just cautioning you that working on a TV is dangerous!

- Mike