When is a fuse too old?

How can you tell when the fuses in your storeroom or plant are no longer usable? We pulled a few tips from Mersen’s Three Clues for Detecting When is a Fuse Too Old for Storeroom Inventory information sheet and added a few quick visual ways to help you determine when you should toss them.

good-vs-bad-fuseVisual Clues
A quick way to tell if your fuses are not longer safe would be to perform a quick visual inspection. Discoloration of copper contacts, fading of text on fuses, and cracks can indicate an old, potentially unsafe fuse. Grimy buildup on fuses can also indicate an old fuse and could increase the possibility of arc flash occurrences. Discoloration in the middle of the fuse could indicate that the fuse was used previously and has blown, also making it unusable.

Other Clues

  1. Functional Obsolescence

When the fuse can’t protect the equipment due to changes in the electrical system needs it is deemed functionally obsolete. If used, it could create a hazardous situation for both your electrical system and employees.

  1. Concealed Damage

One form of concealed damage that can render a fuse unusable is moisture. If a fuse absorbs too much moisture, they lose their safety capacity and are permanently damaged, even if they are later dried out. Water stains on the fuse body and corrosion on the connectors could both be visual signs of moisture but visual signs are not always available.

  1. Fuses Over 10 Years Old

If a fuse is more than 10 years old, they are most likely unsafe and should not be used. It is highly likely that they were exposed to moisture or damaging conditions during their storage period and therefore would be unsafe and unreliable for maintenance. Most fuse manufacturers have a date code on fuses so you can check that to find out the age of the fuse. If the date code is unreadable we would recommend replacing the fuse.

Mersen’s Three Clues for Detecting When is a Fuse Too Old for Storeroom Inventory information sheet full article 

You can purchase Mersen fuses from BgBsupply.com.