How to repair a fuse

Discussion in 'The Projects Forum' started by Gdrumm, Feb 28, 2009.

  1. Gdrumm

    Thread Starter Distinguished Member

    Aug 29, 2008
    I have an 8050A Fluke Benchtop meter which I bought off of Ebay.

    Turns out it has an internal 3 amp 600 volt secondary fuse which is blown. Because of that, I can't use the meter to check current.

    Can I solder a small wire across the end caps of the fuse temporarily, until I can get a replacement? Replacements are not available locally, so I may have to buy one on line thru Fluke.

    If I can solder a wire across, what size should it be?

    I cut open the old fuse, and it had a very thin wire inside, and the wire was surrounded with something that looked like grains of salt, I suspect it might have been silica?

  2. hgmjr

    Retired Moderator

    Jan 28, 2005
    The best thing to do is purchase a replacement fuse. Bypassing the fuse likely will result in irreversible damage to the meter.

  3. SgtWookie


    Jul 17, 2007
    I strongly advise you to NOT attempt to "kludge" a fuse for your Fluke. This is a safety issue, for both the meter and (most importantly) yourself. It's also a calibration issue; as an incorrect fuse will not have the same shunt resistance.

    You can still use the meter to measure current, by measuring the voltage drop across a known resistance. The known resistance can be as simple as a length of wire, or a precision resistor. I have a 1 Ohm 50W resistor that I frequently use for such purposes; very little chance of blowing the meter's fuse (or destroying the meter) that way.

    See this Fluke application note on choosing the correct fuse for your tester:
    It directly addresses your idea of using a wire on page 2. Note the photo on the right. :eek:
    Found the app note on this page at Fluke:
    Last edited: Feb 28, 2009
  4. wr8y

    Active Member

    Sep 16, 2008
    You'd be surprised what you can get at Radio Shack. I get my meter fuses there - mine calls for a 2.5 amp but I get the 2 amp. (Assuming you are in the states or somewhere that Radio Shack has stores - why can't people fill in their location?)

    WOrks for me.
  5. Gdrumm

    Thread Starter Distinguished Member

    Aug 29, 2008
    Thanks for the info.
    I'll order the correct fuse from Fluke.

    I appreciate you.

  6. russ_hensel

    Distinguished Member

    Jan 11, 2009
    Just wrap the fuse in al foil. Then when you buy a new meter you will get a new fuse too. If you live. -- Actually if you can get the right current, but not the right size you could kluge it into the circuit as a temp fix. But if you mess up you could be hurt or loose the meter
  7. eblc1388

    AAC Fanatic!

    Nov 28, 2008
    I agree strongly with SgtWookie that the fuse in the Fluke involves safety issues.

    A fuse also has interrupting capacity, apart from fusing current value. Not all fuses rated at 3A are the same.

    The correct one will save your life while the other might explode. That's why it costs so much to replace the correct fuse. There are alternatives for the fluke fuses but unless your are satisfied that they really are the same you are just just paying for no good reason.