Electrical energy
This energy type is present. This tool does not calculate it.
Contact with energised conductors, arc flash and stored electrical energy can be fatal at levels far below anything a field calculation would flag. Voltage and fault level data belong to engineering studies, not field estimates.
Why isn't this calculated here?
It looks like it should work the same way as a dropped object: energy = voltage x current x time, compared with 1500 J. It doesn't, for two reasons. First, current can't be known before contact: it depends on skin and contact resistance, which varies by two or three orders of magnitude between dry, unbroken skin and wet or broken skin, so the same voltage can imply wildly different "energy" figures. Second, the injury mechanism for electrical contact isn't an accumulated-joules threshold the way a fall is: a few milliamps sustained across the heart's cycle can cause fibrillation, a current-and-duration problem, not an energy-total one. That is why electrical is treated as a presence trigger instead: exposure to 50 volts or more is high energy, full stop, matching the criterion in the EEI High-Energy Control Assessment guide.
Trigger questions
- Is any part of the system energised, or could it become energised during the work?
- Has isolation been applied, locked and proven dead at the point of work?
- Could stored energy remain in capacitors, UPS systems or batteries after isolation?
- Is an arc flash assessment available for the equipment being worked on?
- Is the person doing the work authorised for this system?
Controls to verify
Ticks stay on this screen only. Nothing is saved or sent.
Some energy cannot be reduced to a simple field calculation. Where this energy is present in the work, treat it as high energy: the decision is made by presence, not arithmetic. Use the trigger questions and competent-person verification instead of a number.