Mitigating Arc Flash Hazards with Current Limiting Fuses

Traditional fuses are designed to limit threats to people and property by protecting your electrical system from overheating, fire and arc flash. But increasing safety requirements have created an immediate need to reduce the potential for arc flash even further. OSHA, for example, uses the new requirements of NFPA 70E to judge whether an employer “acted reasonably” in protecting its workers from these arc flash hazards.

Employees may be required to wear additional personal protective equipment (PPE) when accessing areas having higher arc flash potential. Taking action to decrease arc flash potential can reduce PPE requirements, facilitating safe and convenient access to electrical equipment. This can also positively impact personnel productivity.

Why migrate to current limiting fuses?

Arc flash energies can be reduced with faster acting circuit protection devices. Arc mitigating fuses are fast enough to clear a short circuit current in less than one half cycle. These fuses will isolate a faulted circuit before the fault current reaches maximum value, which enables them to:

1. Limit the total energy delivered to an arcing fault.
2. Limit thermal and mechanical stresses created by the fault current.
3. Reduce both the magnitude and the duration of the fault current.
4. Be easily coordinated in both the overload and short circuit regions.

 Can migrating to current limiting fuses save you money?

A lifeline that can be cut by an arc flash can disintegrate. Conductors can vaporize. Bus bars can break. And components like switchgear, MCC buckets and motor starters can be destroyed, bringing your operation to a halt. That incident can cost your business a million dollars – or more – in liability. Add to that the costs of dealing with injuries and equipment repair, and you’re looking at a serious dent on your bottom line.

Consider fast acting fuses as part of your arc flash mitigation strategy.

1. Arc flash mitigating fuses can be installed in addition to circuit breakers to a feeder circuit or replace existing fuses.
2. Mersen class J, RK1, T and L fuses can be applied to reduce energy from an arc flash to very low levels, often requiring minimum PPE.

To get started with arc flash fuses, or for a more comprehensive evaluation, call EECO and ask us about the Mersen Fuse Control program.  If you’d like to learn more, visit the linked articles below:

• Short circuit protection and safety evaluation
• New VFDs Require High Speed Fusing Protection
• Is branch circuit protection enough?
• Are high speed VFD fuses worth it?

Visit the links below to learn more about circuit protection, safety training, inventory analysis, and upgrade services.