Fast blow vs. slow blow fuse

[[email protected]]

Looking at fuse how do you tell difference? Thanks.

 

[Arfa Daily]

Looking at fuse how do you tell difference? Thanks.

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

 

[Jim Land]

[email protected] wrote in @l53g2000cwa.googlegroups.com:

Looking at fuse how do you tell difference? Thanks.

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.

 

[Eeyore]

[email protected] wrote


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

 

[[email protected]]

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.

 

[[email protected]]

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.- Hide quoted text -

- Show quoted text -

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.

 

[Arfa Daily]

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

 

[Michael Kennedy]

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