Establishing an Electrically Safe Work Condition

May is Electrical Safety Month TrainingA product of the EFCOG Electrical

Safety Task Group

NFPA 70E Article 100Definition

• Electrically Safe Work Condition (ESWC) – A state in which an electrical conductor or circuit part has been disconnected from energized parts, locked/tagged in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary.

- ESWC - NFPA 70E required, except when justified, for work on exposed electrical conductors and circuit parts at 50 volts or more

Electrically Safe Work ConditionIt’s a Process!

• Utilizing the site’s Hazardous Energy Control process verify by the following (NFPA 70E – 2009 Article 120.1):

– Identify all possible energy sources – checking up-to-date prints and documentation– Open the disconnecting device(s) for each source– Whenever possible, visually verify switch blades are fully open or draw-out type circuit

breakers are withdrawn to fully disconnected position– Apply lockout/tagout devices per established site policy– Use an adequately rated voltage detector to verify circuit or conductor is de-energized – check

phase-to-phase and phase-to-ground – verifying detector operation before/after each check– Possibility of induced voltage or electrical stored energy – ground conductors before touching

Electrically Safe Working Condition

• Requires adherence to the Hazardous Energy Control process AND the verification process

• NOT established by solely de-energizing circuits or conductors

• Lockout/tagout requirements shall apply to the following (NFPA 70E – 2009 Article 120.2A) :– Fixed/permanently installed equipment– Temporarily installed equipment– Portable Equipment

Lessons Learned• April 2010 – A local electrical repair company was tasked to repair an electric arc

welder at a DOE site.• After troubleshooting, the vendor determined that the welder needed to return to

the vendor's shop for comprehensive electronic repairs. • The vendor verified the disconnect switch in the OFF position before disconnecting

the power cable and used a "tic tracer" to verify no voltage was present before beginning work.

• The vendor disconnected electrical service from the welder in preparation for movement to his truck. The vendor was NOT trained to the Site’s lockout/tagout process.

• A Site Safety Supervisor later discovered the improper electrical disconnection had occurred without using the lock out/tag out process and stopped the work.

Cause description:1. Vendor escorted by Site employees that did not adequately define the work scope or provide adequate oversight.2. Site’s Hazardous Energy Control process was not followed.(Reference ORPS report EM-PPPO-SST-PGDPENVRES-2010-0001)

References- NFPA 70E – 2009 Edition “Standard for Electrical Safety in the Workplace”- ORPS report EM-PPPO-SST-PGDPENVRES-2010-0001