Arc Flash Calculator
Type the value of bolted-fault current and working distance into the upper
boxes, and select the current-limiting fuse you wish to use for protection from
the drop-down box.
The incident energy, PPE category, and Flash Boundary Distance will be
automatically calculated as you type.
The calculator is based on 3-phase tests at 600V with an electrode gap of 32mm
in a 20"x20"x20" box, as described in the IEEE 1584 standard, with Mersen current-limiting fuses in circuit. A distance exponent of 1.5 is used
to adjust the incident energy values for distance.
Use of the IEEE 1584 (2002) set-up only determines the PPE category for
protection against the effects of radiated heat, and does not take account
of the effects of
- pressure blast
- sight or hearing damage
- molten metal showers,
- shrapnel ejected from the arcing zone
- toxic smoke
- plasma jets
- how the arcing fault was initiated
- variation of supply voltage and power factor
- busbar spacing
- grounding arrangements
- actual enclosure size and design
- position of the worker (see diagrams below)
- effect of equipment size, which is not properly taken into account by
the use of a simple distance exponent
- location of the arcing fault with respect to the source of supply
- rapid movement of the arcs, restriking, and changes in length
