A great article came to us from Somesh Gailkwa at New Jersey Engineers. Somesh addresses the important issue of properly designing the electrical room as the "hub" that supplies electrical power throughout the facility. bit.ly/2LW8fcP In our 3 article series, we reference Somesh's article as well as information from the DOE Handbook of Electrical Safety.
This issue seems timely as we have recently noticed an increasingly dangerous use of electrical rooms: often no longer limited to enclosing electrical equipment, but also used for general storage such as mops, brooms, and similar items.
Electrical Room with 7 Panelboards
Both electrical standards and applicable law are clear: "working space around electrical enclosures or equipment shall be adequate for conducting all anticipated maintenance and operations safely, including sufficient space to ensure the safety of personnel working during emergency conditions and workers rescuing injured personnel." OSHA 29 CFR 1910.303 (G)(1)(i) and 2008 NFPA 70 (NEC)
The actual spacing for dimensional clearance is specified in OSHA, NFPA, and the NEC. Sufficient space is always required for access and working space. But even more stringent requirements under OSHA, NFPA, and NEC apply when equipment must be examined, adjusted, serviced, or maintained when energized.
These more stringent requirements spell outs actual spacing requirements for dimensional clearance. The electrical equipment concerned includes panelboards, switches, circuit breakers, switchgear, controllers, and controls on heating and air conditioning equipment.
Why are these rules important? To protect workers by providing adequate space for safe access and egress in work areas with energized equipment. This "dedicated space" also protects the electrical equipment and allows for future expansion.
In our upcoming articles, we will discuss the specific requirements for "dedicated" space and "clearing" space for electrical equipment rated at 600 volts or less and 600 volts or more.
FREE Demonstration: Join us for lunch on April 5th (1st Friday of the month), for a free demonstration of PowerCalc: software that automatically designs the power distribution system inside a facility and simultaneously generated the 1 Line Diagram.