Fuse testing.

[anderslober]

Hello Forum......how do you easily test a fuse to see if it is blown?

I have a very primitive method....but , it does work....I use a mini bulb and a battery..........stack the fuse and the battery....and test the bulb......if 'light', then fuse ok.....if no 'light' then fuse blown.

Can you do it with a DMM? I just have not found out how.......

 

[hpsenicka]

Any DMM can perform this test using the ohmmeter function.

An open (bad) fuse will measure with infinite resistance.

A good fuse will measure 0 Ohms, if the meter is properly calibrated. In practice, meters will often measure a value very close (but not equal) to zero.

 

[anderslober]

you see...I new it was easy...................I am paying the beers!

 

[whoaru99]

While I don't necessarily recommend/endorse the method in all situations, a fuse can usually be checked in-circuit with a voltmeter if the circuit is energized.

In that test, if the fuse is blown/open, you'll read the circuit voltage. If the fuse is good you'll read very low voltage, essentially zero. I usually use this method when checking for a blown fuse in automotive-type situations where it's hard to see if the ATC-type fuse is blown and where they're hard to pull out.

 

[70salesguy]

A good fuse will measure 0 Ohms, if the meter is properly calibrated. In practice, meters will often measure a value very close (but not equal) to zero.

Where are you getting those "superconductor" fuses and test leads? :scratch2:

 

[hpsenicka]

Ebay... where else?