Are all fuses electrically the same?

In the mid 1900s it seems most fuses used in electronics and automotive
were the glass with metal end types. Usually called AGC.

Now a lot of fuses are made of plastic and have a curved element inside.

Are they electrically the same? Meaning, do they blow at the same rate?

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

 

[Phil Allison]

tub...@myshop.com wrote:

--------------------------

In the mid 1900s it seems most fuses used in electronics and automotive
were the glass with metal end types. Usually called AGC.

** Typically with tin plated, copper wire inside.

But many variations exist.

Now a lot of fuses are made of plastic and have a curved element inside.

** You mean the plug-in kind found in automotive use?

Are they electrically the same? Meaning, do they blow at the same rate?

** The above are made with pure tin, have a low melting temp and slow acting.

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

** Huh ?

The ones with coils or springs are SLOW acting fuses.


..... Phil

 

[gray_wolf]

On 10/14/2019 8:55 PM, mpm wrote:

On Monday, October 14, 2019 at 6:32:59 PM UTC-4, tub...@myshop.com wrote:
In the mid 1900s it seems most fuses used in electronics and automotive
were the glass with metal end types. Usually called AGC.

Now a lot of fuses are made of plastic and have a curved element inside.

Are they electrically the same? Meaning, do they blow at the same rate?

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

A fuse heats up, eventually melts, and in doing so, opens the conduction path.
So in that sense, a fuse is a fuse.

That said, at high enough voltage, an open fuse might still conduct if an arc can be sustained across the gap. (Thus, there are different voltages ratings for fuses.)

Then there is the possibility that the fuse might explode. So, more varieties for that.

Some fuses need to blow quickly, other slowly. So, more varieties for that.
The list or requirements goes on and on....

If you are new to fuses (and it sounds like you might be), probably the #1 thing to know is to use the right voltage fuse. Automotive fuses, (like the ATO, ATC and glass ACG fuses that you mentioned) are usually rated to 32 volts DC. So, don't use them in higher voltage circuits. If you over-voltage the fuse, you can't be certain of interrupting the current as an arc could technically form across the fuse, rendering it useless.

Another thing to know: Fuses protect wiring, not equipment. (While they may save your equipment, they're really there to keep the wire from overheating, potentially causing a fire.) Don't count on a fuse to protect anything else. And obviously, a fuse should be placed near the source of the current (to protect as much wiring as possible). If a short occurs before the fuse, the fuse doesn't do anything (it's not even in the circuit).

I'm sure there's tons of great research about fuses on the web.
Find something that's entry level and understandable, and then go from there.

BTW: If you are truly desperate for a replacement ACG fuse, did you know you can solder-suck out the ends and replace the internal wire yourself? Of course, at that point, you won't really know the fuse rating anymore. But it beats chewing gum wrappers wrapped around the fuse. (Barely.)

50years ago I saw a book or an article that had a chart for doing this. It may have
been the ARRL handbook.

 

[Phil Allison]

mpm wrote:

-----------

Another thing to know: Fuses protect wiring, not equipment.

** Not really true, the fuses and breakers in your home are rated to protect cabling - but the much smaller fuses in the supply inlet of electronics are there to prevent or limit damage and fire.

If these fuses are ever severely overloaded by say a short, resulting in an end to end arc, the AC supply fuse takes on the job.

BTW

32VDC fuses have lower than usual resistance so they have less effect on low voltage circuits.

IME they are usually OK to use in *AC* circuits to much higher voltages, even 240VAC because AC current is so much easier to break with a short gap.



.... Phil

 

[mpm]

On Monday, October 14, 2019 at 6:32:59 PM UTC-4, tub...@myshop.com wrote:

In the mid 1900s it seems most fuses used in electronics and automotive
were the glass with metal end types. Usually called AGC.

Now a lot of fuses are made of plastic and have a curved element inside.

Are they electrically the same? Meaning, do they blow at the same rate?

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

A fuse heats up, eventually melts, and in doing so, opens the conduction path.
So in that sense, a fuse is a fuse.

That said, at high enough voltage, an open fuse might still conduct if an arc can be sustained across the gap. (Thus, there are different voltages ratings for fuses.)

Then there is the possibility that the fuse might explode. So, more varieties for that.

Some fuses need to blow quickly, other slowly. So, more varieties for that..
The list or requirements goes on and on....

If you are new to fuses (and it sounds like you might be), probably the #1 thing to know is to use the right voltage fuse. Automotive fuses, (like the ATO, ATC and glass ACG fuses that you mentioned) are usually rated to 32 volts DC. So, don't use them in higher voltage circuits. If you over-voltage the fuse, you can't be certain of interrupting the current as an arc could technically form across the fuse, rendering it useless.

Another thing to know: Fuses protect wiring, not equipment. (While they may save your equipment, they're really there to keep the wire from overheating, potentially causing a fire.) Don't count on a fuse to protect anything else. And obviously, a fuse should be placed near the source of the current (to protect as much wiring as possible). If a short occurs before the fuse, the fuse doesn't do anything (it's not even in the circuit).

I'm sure there's tons of great research about fuses on the web.
Find something that's entry level and understandable, and then go from there.

BTW: If you are truly desperate for a replacement ACG fuse, did you know you can solder-suck out the ends and replace the internal wire yourself? Of course, at that point, you won't really know the fuse rating anymore. But it beats chewing gum wrappers wrapped around the fuse. (Barely.)

 

[amdx]

On 10/14/2019 6:05 PM, Phil Allison wrote:

tub...@myshop.com wrote:


Are they electrically the same?

Some fuses are different than other fuses.

do they blow at the same rate?

Some fuses will have differing rates that they open at depending on the
change of the current.

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

Well what are you including?

All 4 amp fuses are not the same.
Some will open as the rated current is exceeded, others will set there
for 30 seconds at the rated current.
Some will arc over at higher voltages, other help damp an arc.
It might be fun for you to use that new search engine called Google, to
try to find more information about fuses.
Let us now what you find out that surprises you.
Mikek

 

[Michael Terrell]

On Monday, October 14, 2019 at 6:32:59 PM UTC-4, tub...@myshop.com wrote:

In the mid 1900s it seems most fuses used in electronics and automotive
were the glass with metal end types. Usually called AGC.

Now a lot of fuses are made of plastic and have a curved element inside.

Are they electrically the same? Meaning, do they blow at the same rate?

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

AGC is from Bussman

<http://www.cooperindustries.com/content/public/en/bussmann/electrical/products/electronic_smalldimension/elx_1_4_x_1-1_4_/agc.html>

3AG is the same specs, from Littelfuse

<https://www.littelfuse.com/industries/consumer-electronics/fuses/3ab-3ag--6_3x32mm--fuses.aspx>

 

[Robert Baer]

tubeguy@myshop.com wrote:

In the mid 1900s it seems most fuses used in electronics and automotive
were the glass with metal end types. Usually called AGC.

Now a lot of fuses are made of plastic and have a curved element inside.

Are they electrically the same? Meaning, do they blow at the same rate?

I am NOT including the special types of fuses such as the fast blow
types that contain a spring inside.

In a word, NO.
Even amongst the same physical construction, the answer is NO.