overvoltages
to
an
appropriately low level.
•
Any
high-voltage,
low-energy
source
derived
from
a
highwinding resistance
transformer, such as the
high-voltage section of a
copier.
CAT
Ⅱ
Single-phase
receptacle
connected
loads
• Appliance, portable tools,
and other household and
similar loads.
• Outlet and long branch
circuits.
• Outlets at more than 10
meters (30 feet) from CAT
III source.
• Outlets at more that 20
meters (60 feet) from CAT
IV source.
CAT
Ⅲ
Three-phase
distribution,
including
single-phase
commercial
lighting
• Equipment in fixed
installations,
such
as
switchgear and polyphase
motors.
• Bus and feeder in
industrial plants.
