ESWC

OSHA regulations for electrical work restrict work for non-qualified workers to equipment in an ESWC. This means that equipment operating at voltages equal to or greater than 50 volts cannot be energized while work is being performed if conditions exist, as follows:

• Work is being performed in the limited approach boundary.
• The employee interacts with equipment where conductors or circuit parts are not exposed but there is still likelihood of injury from an exposure to an arc flash hazard exists.

To ensure that the equipment is electrically safe, the following steps must be taken:

• Identify all possible power sources for the equipment.
• Interrupt the load and disconnect power from the equipment.
• Visually verify that all blades of the disconnecting devices are fully open or that circuit breakers are withdrawn to the fully disconnected position.
• Release stored electrical energy.
• Lockout and tagout the circuit; more detail on how to do this will follow.
• Test each phase conductor or circuit part to verify the absence of voltage.
• Ground all power conductors, if necessary.
• Use equipment in accordance with in accordance with the listing, labeling, and manufacturer's instructions.

Employees must also apply a human error concept to workplace electrical safety. To do so, a qualified person must be trained in factors, as follows:

• Identify possible causes of human error
• Identify how human performance can affect job performance
• Use human performance tools provided in Annex Q of NFPA 70E
• Complete a job site review of human performance tools used

To learn more about Arc Flash Safety visit our OSHA Construction Arc Flash Safety Online Training web page.