Product Description Time-Delay, Dual-Element S Series Plug Fuses Provide A Rejection Feature (When Used Alone Or With Fu Stat Adapters To Retrofit Edison Base Holders) To Prevent Overusing Of Branch Circuits. 4 Pack 15 Amps Non-Tamp Dual-Element, Time-Delay Plug Fuse Plastic Base With Rejection Threads. Use In Typical Application Like Residential Load Centers Applications Benefiting From Fuse Rejection Ul Listed. From The Manufacturer Heavy-Duty Type S Fuse For Critical Circuit Protection. Used For Air Conditioners, Furnace Blower Motors, Swimming Pool Pumps, Deep Freezers Or Any Circuit Where Motors Frequently Turn On And Off. Used For All Commercial Applications, The Type S Rejection Base Plug Fuse Is An Industrial Strength Product. It Provides Superior Protection, Yet Will Not Open Under Repeated Motor Startups. Available In A Wide Amp Range To Permit Exact Sizing For Motor Protection. The Rejection Base Threads Prevent A Larger Amp Fuse From Being Used. Example: A 30 Amp Fuse Cannot Be Installed In A 20 Amp Receptacle Because Of The Different Sized Threads. Heavy-Duty Fuse. These Fuses Thread Into Fuse Receptacles. Threaded Fuse Type: Rejection Base (Porcelain Threads). Not Interchangeable With Edison Base (Brass Threads) Type. Heavy-Duty (S) Category Plug Fuse. The Heavy-Duty Fuse (S) Is An Industrial Strength Product Featuring The Exclusive Cooper Bussmann Dual-Element Construction. This Spring Loaded Design Provides Superior Short-Circuit And Overload Protection. The S Fuse Has More Time-Delay Than The Medium-Duty Fuses In Order To Better Protect Motors And Critical Residential Circuits. Plug Fuses Are Rated For A Maximum Of 125Vac. Plug Fuses Are Often Used In Residential And Industrial Branch Circuit And Motor Protection. Fuses Are Used To Protect Furnace Blower Motors, Pumps, Power Tools, Garage Door Openers, Etc. Motor Protection Fuses Are Usually Used In Conjunction With Branch Circuit Protection. The Fuse Is Often Located In A Box Cover Unit. Plug Fuses Provide A Compact And Inexpensive Method To Prevent Damage To Electrical Motors. They Help Reduce Downtime And Lower Maintenance Costs By Opening The Circuit When A Dangerous Overload Is Present. When Used For Residential Branch Circuit Protection, Fuses Are Typically Located In The Main Fuse Panel.