ECNR/ECSR dual element fuses are recommended for AC power distribution system mains, feeders and branch circuits having inductive loads (motors, transformers) or non-inductive loads (lighting, heating) where the available short circuit current does not exceed 200000 rms symmetrical amperes. These dual element, time delay fuses have minimum industry standard time delay of 10 sec at 5 times the fuse rating (8 sec minimum for 250 VAC, 30 A and less). The time delay characteristics of these fuses typically allows them to be sized closer to the running ampacity of inductive loads to reduce cost and provide improved over current protection. These fuses will override normal equipment current surges to reduce unnecessary fuse openings. They are the most popular fuses used in the industry and the most economical for most applications, especially motors and transformers. They have moderate current limitation.