Three people in critical condition from Google data center 'electrical incident'

Re:Three people in critical condition from Google data cente... by c_o_n_v_e_x on Tuesday August 09, 2022 @02:25AM (#32394809)

Arcs are rated by calories per square centimeter. There's a lot factors that go into arc ratings, more than just voltage. To give a frame of reference, a flame from a lighter on the tip of your finger for 1 second is considered 1 calorie. Arc flash PPE ratings start at 4 calories and can go above 100.

The high cal rated PPE does indeed look like bomb squad gear.

[ Parent | on HN ]

Re:Three people in critical condition from Google data cente... by MayeulC on Tuesday August 09, 2022 @04:17AM (#32395416)

It's weird to rate it in calories (∝ joules, W.s) instead of Watts.

[ Parent | on HN ]

Re:Three people in critical condition from Google data cente... by closewith on Tuesday August 09, 2022 @05:12AM (#32395698)

Energy is used rather than power as it's the cumulative effect in energy incidents that causes damage. In most of the world, the unit is J/cm2, though.

[ Parent | on HN ]

Re:Three people in critical condition from Google data cente... by MayeulC on Saturday August 13, 2022 @07:53AM (#32449042)

Ah, all right, I understand if it's used to rate accumulated damage for incidents. For ongoing arcs, or comparing them however, I think it's a weird.

A small arc, not even dangerous to touch, could have the same energy rating as a gigantic one if you measure the first over a year and the second over a millisecond.

[ Parent | on HN ]