Cartridge fuses are what's used to prevent excessive amounts of current from overloading an electrical panel in most older homes or buildings. Cartridge fuses do not have the advantage of circuit breakers that automatically cut off electricity when sensing overload. This is why testing cartridge fuses should be done regularly to make sure that they are not blown or tripped, in order to prevent potentially fatal accidents.
- Keep in mind some really basic safety measures to avoid electrocution. Of course, you will need to turn the electrical panel completely off before you try and attempt to test the cartridge fuses within. Add to that the necessity to use only the correct tools and protective gears to avoid injuring yourself. You will need a pair of the correct size of fuse puller for this task. Fuse pullers are typically made from plastic and can be readily bought from your local hardware or electrical store. Also, it will be smart to wear protective glasses for your eyes when you perform the succeeding steps described below.
- Know what cartridge fuses look like. Cylindrical cartridge fuses are what's commonly used in most of the older homes that are not too big. These types of cartridge fuses have sensitive contact links on each of their ends that are typically wrapped in highly conducting materials such as copper. Bigger buildings that still have the old system of electrical wiring will most likely still be installed with the bigger knife-blade type cartridge fuses. Though still cylindrically shaped, knife-blade cartridge fuses are installed with blades on each end, hence its name. Cartridge fuses are typically contained within the electrical panel of your home.
- Take the cartridge fuse out from its slot. Open the electrical panel to expose the cartridge fuses within. Now, identify which cartridge fuse you need to have tested. After that, insert the fuse puller into the middle section of the identified cartridge fuse and gently pull it out of its respective slot.
- Finally test the cartridge fuse. Place the recently pulled cartridge fuse on a flat and level table. Now, grab your multi-meter tester and first set it to continuity. This simply means to have it set at the lowest mark in ohms. Now, have each of the multi-meter's contact links settled on each side of the cartridge fuse's edge. The multi-meter tester will output a reading of zero if the cartridge fuse is still working fine. Otherwise, it will read infinite if the cartridge fuse is blown or tripped.
Once done with the testing and satisfied with the results, then you can replace the cartridge fuse in its usual slot in the electrical panel. Remember, only do this with the use of the fuse puller to avoid accidental electrocution.