Arc flash/arc blast hazard labels inform personnel of the arc flash/arc blast hazard and the required PPE at each switchboard or arc flash/arc blast hazard location. The labels should present the following information:
- electrical hazard and danger symbols;
- arc flash/arc blast boundary in metres;
- incident energy in cal/cm2; and
- mandatory PPE requirements.
The PPE specified is based on incident energy at the working distance depending upon configuration, barriers and activity to be undertaken.
Four types of hazard labels are used to convey the above information at each assessable location:
- Individual Arc Flash/Arc Blast Label:
An individual arc flash/arc blast label depicts the arc flash/arc blast hazard applicable to a specific or individual panel to which the label is fixed based on the calculation methodology specified in IEEE 1584. Individual labels are used where panels are not covered by a group label.
- Group Arc Flash/Arc Blast Label:
A group arc flash/arc blast label depicts the arc flash/arc blast hazard that is common to a group of circuits at an assessable location based on the calculation methodology specified in IEEE 1584. This would typically apply to all outgoing cubicles on an MCC.
- Reference Arc Flash/Arc Blast Label:
A reference arc flash/arc blast label is typically applied to individual cubicles of larger panels to direct personnel to the location of the main arc flash/arc blast label. It is used in conjunction with a group label.
- Assessed Arc Flash/Arc Blast Label:
An assessed arc flash/arc blast label is applied to panels that have been assessed using the NFPA70E methodology, rather than the preferred IEEE 1854 methodology. This may be due to limited equipment details needed to support the IEEE calculations. Assessed labels are used as an interim hazard warning measure until sufficient equipment details are gathered to execute the IEEE calculations.