Mersen plug fuses are for industrial and residential applications. Standard non-time delay fuses are for receptacle and lighting circuits. Standard time delay fuses are for motor loads. For Canadian requirements, a type "P" fuse is used for non-motor loads and type "D" fuses are used for electric heating and cycling loads circuits. Both fuses have low melting point temperature elements. Low-Temp time delay plug fuses have thermal sensitivity are also for cycling loads and motor circuits. Type "S" plug fuses are time delay and tamper resistant.