When must emergency power come on and how long must it last should a power failure occur?
A) Emergency power must come on within 5 minutes of a power failure and last for a minimum of 4 hours.
B) Emergency power must come on within 10 minutes of a power failure and last for a minimum of 6 hours.
C) Emergency power must come on within 30 minutes of a power failure and last for a minimum of 8 hours.
D) Emergency power must come on within 60 minutes of a power failure and last for a minimum of 12 hours.
