Need an electricians advice about a fuse

[Maximilian]

Ive bought some 2A slow blow fuses from ebay before for my Z5500 speaker sub. They worked great, the difference between the slow blow ones and the normal ones was that the slow blow fuse wire inside coiled and overall thicker than the normal one.

Ive bought some more 2A slow blow fuses from ebay, but they look different inside, instead of the coil they have what looks like a normal 2A fuse wire but theres a lump in the middle of the fuse wire. Are these slow blow fuses ive been sent?

Picture of the three fuses i drew in paint

 

[Analog]

What is the part no. stamped on the end?

 

[Cogman]

Fuses depend very much on surface area, the more surface area the more power can pass over the fuse before it blows. The difference is the method employed to increase the surface area. As long as the ratings are about the same and the size is the same, I don't see a problem (except you run a higher risk of damaging your equipment when you use "Slow Blow" fuses. Slower the fuse, the more damage from high electrical spikes will result)

 

[IEC]

Why would you want your fuses to be slow blow? Wouldn't you want them to do their job properly and blow out quickly to prevent damage?

 

[Maximilian]

Originally posted by: Analog
What is the part no. stamped on the end?

T2AL 250V

On the other end there is an "H" with a circle around it.

Originally posted by: Spartan Niner
Why would you want your fuses to be slow blow? Wouldn't you want them to do their job properly and blow out quickly to prevent damage?

No, the Z5500 requires a slow blow fuse, normals 2A fuses burn out instantly or very quickly.

 

[Mark R]

Originally posted by: Spartan Niner
Why would you want your fuses to be slow blow? Wouldn't you want them to do their job properly and blow out quickly to prevent damage?

Some types of device may take brief power surges under normal operation, but still require more protection against fire than would be provided by a very high rating fuse.

Classic examples are amplifiers, motors or equipment containing high-grade transformers. These may take big surges when switched on, but once capacitors have charged and transformers stabilised and motors got up to speed then such high currents would be abnormal and require protection against.

Mains power circuit breakers are similar, but available in several speed grades. Normal is class B - these offer a brief delay (a couple of seconds) for moderate surges (3x maximum rating), but for industrial equipment like HID lighting or heavy motors, this may not be enough, and there are class C (delayed) and class D (very delayed) options for this type of equipment. Equipment containing big capacitors (like PC PSUs) or motors can take big power surges when switched on (e.g. a 650 W PC PSU can easily take an 80 A surge from the mains when plugged in) - a delay in the the fuse and breaker is essential to prevent false tripping.

 

[Maximilian]

So have i got a slow blow fuse or has the guy on ebay sent me something else?

 

[Umberger]

Originally posted by: Soviet
So have i got a slow blow fuse or has the guy on ebay sent me something else?

looks to me like it's a slow blow....

linky

hope that helps...

:beer:
Umberger

 

[Analog]

Originally posted by: Umberger

Originally posted by: Soviet
So have i got a slow blow fuse or has the guy on ebay sent me something else?

looks to me like it's a slow blow....

linky

hope that helps...

:beer:
Umberger

yep, that's why I asked for the part no FTW.

 

[alkemyst]

Originally posted by: Spartan Niner
Why would you want your fuses to be slow blow? Wouldn't you want them to do their job properly and blow out quickly to prevent damage?

slow blows do their job properly. There is a reason for them.