Replacement fuses for multimeter test leads

derrick

Need to replace fuses in multimeter test leads that contain integral fuses but due to the array of type and price I am unsure which are the correct fuses.

i am looking at this page which sell the same "named" fuses, SIBA. http://cpc.farnell.com/search?st=SIBA%20fuses

These are the test leads

• Fused test lead set with shrouded 4mm plugs
• Interchangeable probe and crocodile clip termination
• Silicone lead construction
• Integral fuse within probe body

Details on the original fuses are:

Size: 32mm x 6.3mm.
The following is printed on the fuses:- SIBA, F500mA, 600v, L-Nr 70 094 63

When I put L-Nr 70 094 63 into Google, CPC comes up with this, but nearly £1 each, minimum of 10

If I got something with a higher mA is that better or does it go the other way, i.e is lower mA better?


Am using them with this multimeter.



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Heedtheadvice

That fuse you have located is incorrect - it has a very high current fuse rating.

That type of test lead is designed for insulation testers and as such has a 500mA current rating (as a safety feature). When used for that purpose it should be replaced with an identical rated fuse i.e a ceramic fast acting 500mA 6.3 X 32mm rated at 600volts -as you post, assuming that is correct.

In practice the leads are not really ideal for your multimeter as it has the capability for measuring 10A current and that would likely blow the Siba fuse in the test leads. Further there could be a voltage drop across the fuse that will give a slightly erroneous voltage measurement when measuring voltages. The meter does not need fused test leads and should have it's own internal fusing. (Edit two: multimeter leads often have no fusing themselves!)

In practice a highly rated fuse in the leads would be fine when used with the meter but they would then not offer protection when used with an insulation tester!!

So you need to decide if you are going to replace with a correct equivalent (not necessarily a Siba make) so you have probes meeting their original spec; accepting the risk outlined above and fitting a similar fuse but rated at 10A (are the leads suitable for that current level????); or just buy some leads suitable for a multimeter!

The type of fuse fitted is not cheap. You may well be able to search around and get them cheaper than at Farnell but ensure that they are a reputable brand. If you go down that route it is hardly worthwhile just buying one!

derrick

I bought the leads separately from the meter and did not know they came with fuses, I got them for the crocodile clips functionality as holding probes sometimes needs a third hand.

So 500mA is equivalent of 0.5A ? Meaning the one I linked to is 10 times the rating?


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forgotmyname

Buy some decent leads without fuses?

You dont use that meter to test mains electricity do you?

The meter is fused why buy fused leads?

John_Gray

For a meter costing £7 it's not surprising that the manufacturer didn't bother putting fuses into the leads!

Frozen_up_north

Take a look at this video of a nice £5 meter, around 6 mins into the video you will see how dangerous they are.

https://youtu.be/OEoazQ1zuUM

I am a Fluke user...

forgotmyname

I have plenty of cheap meters, but wouldnt dream of putting them anywhere near the mains.

Fine for sub 12v DC work though. But why do you need fuses in the leads?

paddyrg

Frozen_up_north wrote: »

Take a look at this video of a nice £5 meter, around 6 mins into the video you will see how dangerous they are.

https://youtu.be/OEoazQ1zuUM

I am a Fluke user...

In fairness the cheapo meter is from Farnell, so not as bad as an ebay special.

derrick

forgotmyname wrote: »

But why do you need fuses in the leads?

Read post #3.

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Heedtheadvice

derrick wrote: »

So 500mA is equivalent of 0.5A ? Meaning the one I linked to is 10 times the rating?


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Yes and yes.

derrick

Heedtheadvice wrote: »

Yes and yes.

These leads will only be used for car, (12v DC), and DC batteries, when I want/need to use the crocodile clips, so if I managed to purchase non fused crocodile leads it would be no different than putting to high a fuse rating in these leads, but I am aware that the leads may not be for current levels as outlined in post #2.

So with the above in mind would I be OK with one of the following?

One

Two

Three



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