An arc flash can result in a blinding light. Without adequate protection, the result could be temporary or permanent eye injury.

The latest arc flash testing includes some light measurements using Lux as the unit of measure.
Lux: measurement of illuminance and equal to one lumen per square meter.

For a frame of reference, a typical overcast day is approximately 1000 lux. Direct sunlight is upwards of 100,000 lux.
An Arc flash 3 meters away may result in over 1 million lux

One arc flash test had a recorded 13.1 million lux - approximately 130 times brighter than direct sunlight!

Several years ago, I had an encounter with temporary blindness when the lab tech closed the circuit breaker on an arc flash test without warning. At that moment, I was looking directly at the test set up from the control booth. After the unexpected blinding flash, all I could see was a very vivid purple for the next 20 minutes. The purple eventually faded and my eyesight returned to normal. I was lucky – not everyone is.

Here is this week’s question:

Have you or anyone you know been temporarily blinded from an arc flash?
Yes – Me
Yes – Colleague
No

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