Is there a field test for Fuses to determine how they will perform?

[Machine Gun Kelly]

Is there a non destructive field test on low, medium and high voltage fuses to determine how they will preform?

I have at work 200+ fuses of various sizes and voltage ratings some are probably unused some have been in service I have no way of telling because they are out of the box. I will assume that they check good with a ohmmeter or open indicator.

What I want to do is test them all and trash the ones that may have seen fault current but did not open but if they would come under a load they would open unnecessary.

I do have access to a ductor and I was wondering somewhere world of standards that there might a standard that says for example that a 400 amp 5KV fuses should have so many milliohms resistance and if it has more it will open at say 325 amps.

Thanks for your help.

MGK

[AlexT90]

You should be fine to put a 10A ductor on them unless you are talking about control fuses (< 10A) then you would want to use less current otherwise you could blow the fuse, this is how fuses are usually field tested. Compare the values of each fuse type to a fuse of the same type, they shouldn't be more than 50% of the lowest value.

Another option would be to push 100 amps of AC through the fuses with a high current test set and measure the voltage drop with a fluke. Not sure if any standards exist for what you are asking but I will keep an eye out.

[Machine Gun Kelly]

Alex Thanks for your help . I do have access to a high current test set also . I have 70 years of fuses to test among other things to do. Don't know when I will get started but it should be sometime this summer.
With the information you gave me I have a idea as to what to look for.

Thanks again

MGK

[wrh9278]

NETA maintenance specs has a guideline of 15% variance for fuse resistance. The 50% variation is for bolted connections and main contact assemblies. If the resistance of fuses checked in a disconnect deviates by more than 15%, further investigation should be made.

Fuses that are within the manufacturer’s resistance tolerance and meet industry standards for performance may have resistance values that deviate by more than 15%. Generally, when a fuse is found out of tolerance, the percentage difference is far greater than 15% (an order of magnitude or greater).

Here are some other points on fuse maintenance that you may find helpful:

The internal parts of modern current-limiting fuses do not require maintenance. There are no adjustments or settings necessary—or possible. However, like all electrical components, the integrity of fuses can be negatively affected by the surrounding environment and components.

It is important to periodically check fuse bodies, fuse mountings/ clips and adjacent conductor terminations for signs of overheating, poor connections or insufficient conductor ampacity. Dirty fuse contact points can be polished using a scotch brite type abrasive pad.

http://www.maintenancetechnology.com...nated-systems/