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Don’t rely solely on PPE




Engineering less risk



Engineering controls can be broken into these categories:


  • viewing windows that allow thermal scanning of equipment without exposing live parts;

2. Passive containment: Arc-resistant equipment is designed to withstand the effects of an internal arcing fault and to redirect gasses and particles away from employees close by. Instead of reducing duration or energy, it contains energy via doors and covers before redirecting and safely venting.

Employees are unprotected during maintenance or any time the doors are open or covers removed. Due to installation and venting requirements, retrofitting usually isn’t an option.

3. Passive protective devices: Devices, schemes, and settings are selected so that their response to arcing fault currents, while no different than to other faults, is fast enough to satisfactorily reduce energy levels.

4. Active protective devices: Techniques that clear (or quench) faults very quickly, typically in less than a few cycles, using sensing techniques that differentiate between arc flash and other fault types.

5. Interactive protection: Employee initiates protective device clearing.

The use of any one of these controls, or a combination of two or more, depends on the number of application-specific situations unique to each circumstance.