Amp-Trap 2000 SmartSpot time-delay A6D-R fuses provide IEC Type 2 "no damage" protection to existing mains, feeders, and branch circuits serving motor and non-motor loads. A6D-R fuses will open fast enough under extreme fault conditions for maximum short circuit protection to prevent damage to motor starters, switches, and other circuit components, yet also provide the time-delay needed for motor in-rush currents. A6D-R fuses can be used to replace obsolete 600V Class H, K or RK5 fuses already installed in the field.