Dual-Element Time-Delay Fuses

How to Choose Dual Element
Time Delay Fuses for Power Circuits

Dual Element Time-Delay Fuses are designed for AC power distribution system mains, branch and feeder circuits with inductive loads (transformers, motors) or non-inductive loads (heating, lighting) where the short-circuit current is not beyond 200,000 RMS symmetrical amps. Dual Element Fuses are among the most frequently used fuses in industry because of their economy, particularly in Dual Element Eaton E-Rated Industrial Fusetransformers and motors. Cooper Bussmann Class RK, Littlefuse Class RK and Edison Class RK Time Delay Fuses are popular industrial fuse choices in the RK Fuse Class.

For AC motor loads, single-element fuses may require sizing at 300% of an AC motor current to hold starting current. Dual-element, time-delay fuses can be sized more proportionate to motor loads. Knowing industrial fuse ratingsresistance values and selecting the proper industrial fuse hardware for equipment and components such as those found in motor starters and transformers can help you select the right time delay fuse for the job.

Benefits of Dual-Element Fuses

  1. Permit the Use of Smaller and Less Costly Switches — Saves you money
  2. Better Short Circuit Component Protection —  Fast Response to Overloads
  3. Better Motor Protection in Elevated Ambients — Optimum motor protection in high temperatures
  4. Possibility of arc-flash hazard reduced — Safety
  5. Better Selective Coordination Upstream/Downstream — Blackout Prevention

[pullquote align=”left” cite=”” link=”” color=”” class=”” size=””]Dual-element, time-delay fuses allow for sizing closer to motor loads. This translates to cost savings, improved safety and performance.[/pullquote] [pullquote align=”full” cite=”” link=”” color=”” class=”” size=””]Need it Now? We can be reached toll free 24 hours a day, 7 days a week, for emergency service.[/pullquote]

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Contributing Author: Greg Carter

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