Innnnteresting. Elsewhere, same handbook, the translate it as
Basic Lightning Insulation Level.
hmmmmm.
ANYWAY, i can put in the tables, if interested, sample:
kV (working BIL (kv) Clearance to
ground phase 'people' roadways
7.5KV 95 6" 7" 8 ft 20 ft
Now i will ASSume everyone on this list understands that 7.5 KV sparkover is
A LOT less than 6" <grins>, with the 6" providing working margin for
95 KV surges, lightning, or other...
regards
dwp