4
Symbols
CAT.IV
The circuit from the service drop to the service entrance, and
to the power meter and primary overcurrent protection device
(distribution panel)
CAT.III
Primary electrical circuits of the equipment connected directly to
the distribution panel, and feeders from the distribution panel to
outlets.
Instrument with double or reinforced insulation
#
User must refer to the explanations in the instruction manual.
This instrument meets CAT. III 300V/ CAT.IV150V. To ensure safe
operation of measuring instruments, IEC 61010 establishes safety standards
for various electrical environments, categorized as CAT.II to CAT.IV, and
called measurement categories. Higher-numbered categories correspond
to electrical environments with greater momentary energy, so a measuring
instrument designed for CAT.III environments can endure greater momentary
energy than one designed for CAT.II.
O
: Circuits which are not directly connected to the mains power
supply.
CAT.II : Primary electrical circuits of equipment connected to an AC
electrical outlet by a power cord.
CAT.III : See above table.
CAT.IV : See above table.
