2. FUSES: Fuses perform the same function as a breaker,
except when a fuse blows, it has to be replaced.
There are cartridge fuses and
screw-in fuses. Cartridges look kind of like a shotgun shell. They mount in a little rack that pulls in and
out of a bracket
fuses screw in and out like light bulbs. Some have a glass window on top and metal threads on bottom.
When a fuse blows, its
internal metal strip breaks and the window may get discolored. Be sure to replace a fuse with the exact same amperage-rated
and 20 amp fuses are the most common size ratings. Some fuses have a smaller screw base and are called "non-tamperable,
threads vary in size so they can't be accidentally replaced by another type. When you install a fuse, screw it in snug,
and then give an extra 1/4-turn to make a solid connection.
Other fuses are rated as "slow-blow"
or "time delay." They take a little longer to blow and are made to withstand short, extra surges
of power -- like a motor starting.
buying replacements, be sure to get the right fuse types. It's also a good idea to get a couple extra
fuses of each type to keep on hand when working on circuits.