Plug Fuse, Nonindicating, 20A, TL Series, Time Delay, PK 4

Time-delay plug fuses are medium- to heavy-duty fuses for protecting residential or industrial electrical circuits with motors, relays, or solenoids. These slow-blow plug fuses tolerate temporary inrush currents without opening. Series SL fuses are medium-duty fuses for residential circuits. Series S and T fuses provide heavy-duty protection for industrial motors or critical residential circuits. Series SL and S fuses have a porcelain-threaded rejection base that mates with a rejection adapter in the fuse holder to prevent installation of the wrong size fuse. Series T fuses have a brass-threaded Edison base that screws directly into a fuse holder.

Plug fuses are screw-in fuses for protecting against overcurrent in residential and industrial branch circuits as well as motor circuits. They are commonly found in a box cover unit or main fuse panel and are used to prevent damage to equipment such as pumps, power tools, and HVAC blowers. These plug fuses are color-coded by voltage to help prevent installation of a mismatched fuse. They have a window that reveals whether the fuse element has blown.