Hioki 3283-20 - Measurement categories

6
Safety Information
Measurement categories
To ensure safe operation of measurement instruments, IEC 61010
establishes safety standards for various electrical environments,
categorized as CAT II to CAT IV, and called measurement
categories.
DANGER
• Never use a measuring instrument whose measurement
category is lower than the location in which it will be
used. Doing so may result in a serious accident.
• Never use a measuring instrument with no category
labeling in a CAT II to CAT IV measurement category.
Doing so may result in a serious accident.
The 3283-20 conforms to the safety requirements for CAT III (300 V)
measuring instruments.
CAT
Ⅱ：
When directly measuring the electrical outlet receptacles
of the primary electrical circuits in equipment connected
to an AC electrical outlet by a power cord (portable tools,
household appliances, etc.)
CAT
Ⅲ：
When measuirng the primary electrical circuits of heavy
eqiupment (fixed installations) connected directly to the
distribution panel, and feeders from the distribution panel
to outlets
CAT
Ⅳ：
When measuring the circuit from the service drop to the
service entrance, and to the power meter and primary
overcurrent protection device (distribution panel)
T
Outlet
CAT II
Internal wiring
Distribution panel
Service entrance
Service drop
CAT IV
Power meter
CAT III
Fixed installation