4
__________________________________________________
_____________________________________________
CAT I Secondary electrical circuits connected to an AC electrical
outlet through a transformer or similar device.
CAT II Primary electrical circuits in equipment connected to an AC
electrical outlet by a power cord (portable tools, household
appliances, etc.)
CAT III Primary electrical circuits of heavy equipment (fixed
installations) connected directly to the distribution panel, and
feeders from the distribution panel to outlets.
CAT IV The circuit from the service drop to the service entrance,
and to the power meter and primary overcurrent protection
device (distribution panel).
Measurement categories (Overvoltage categories)
This product complies with CAT I safety requirements.
To ensure safe operation of measurement products, IEC
61010 establishes safety standards for various electrical
environments, categorized as CAT I to CAT IV, and
called measurement categories. These are defined as
follows.
Higher-numbered categories correspond to electrical
environments with greater momentary energy. So a
measurement device designed for CAT III environments
can endure greater momentary energy than a device
designed for CAT II. Using a measurement product in an
environment designated with a higher-numbered category
than that for which the product is rated could result in a
severe accident, and must be carefully avoided.
Never use a CAT I measuring product in CAT II, III, or IV
environments. The measurement categories comply with
the Overvoltage Categories of the IEC60664 Standards.
