Question 2: When commissioning live panels in construction areas while other trades are working in the same vicinity, what recommendations do you make to determine the proper size of the restricted work area?

If the area is accessible to all workers, then you must set up a barrier. In OSHA a ?barrier? is a means to notify qualified and unqualified persons that there is a hazard and they are not to enter. In the case of an electrical hazard, red hazard tape would be used supported by saw horses, cones or other means. A ?barricade? is a physical barrier restricting access to hazardous areas.

In NFPA 70E there is a table / formula for determining the ?Limited Approach Boundary? and in almost every instance it is less than the ?Arc Flash Boundary? A rule of thumb is to use the arc flash boundaries as follows: 120/240 volts = 4 feet, 240/480 volts = 10 feet and anything over 480 volts shall be 20 feet.

Other safety factors must also be considered when setting up a restricted area. A crew of plumbers working with copper pipe could accidentally contact live parts within the service panel. Keep in mind, that a service panels with a TempCover® offers more protection than against accidental contact than an open service panel.