DVM894
V. 01 – 21/01/2015
6
©Velleman nv
4.
Overvoltage/Installation Category
DMMs are categorized depending on the risk and severity of transient overvoltage
that might occur at the point of test. Transients are short-lived bursts of energy
induced in a system, e.g. caused by lightning strike on a power line.
The existing categories according EN 61010-1 are:
CAT I
A CAT I-rated meter is suitable for measurements on protected
electronic circuits that are not directly connected to mains power, e.g.
electronics circuits, control signals…
CAT II
A CAT II-rated meter is suitable for measurements in CAT I
environments and mono-phase appliances that are connected to the
mains by means of a plug and circuits in a normal domestic
environment, provided that the circuit is at least 10 m apart from a
CAT III, or 20 m apart from a CAT IV environment. E.g. household
appliances, portable tools…
CAT III A CAT III-rated meter is suitable for measurements in CAT I and
CAT II environments, as well as for measurements on (fixed) mono- or
poly-phased appliances which are at least 10 m apart from a CAT IV
environment, and for measurements in or on distribution level
equipment (fuse boxes, lighting circuits, electric ovens).
CAT IV A CAT IV-rated meter is suitable for measuring in CAT I, CAT II and
CAT III environments as well as on the primary supply level.
Note that for all measurements on equipment for which the supply
cables run outdoors (either overhead or underground) a CAT IV meter
must
be used.
Warning:
This device was designed in accordance with EN 61010-1 installation
category CAT III 600V. This implies that certain restrictions in use apply that are
related to voltages and voltage peaks which can occur within the environment of
use. Refer to the table above.
This device is suitable for measurements up to 600 V:
measurements in/on low-voltage distribution boards (distribution boards behind
meter box)
measurements on (fixed) mono- or poly-phased appliances and circuits except
in CAT IV environments (e.g. mains outlets, electric ovens, lighting circuits, bus
bars, low-voltage distribution boards and circuit breakers).
This device is NOT suitable for:
Voltages above 1000 V
Measurements on distribution equipment and outdoor installations including
meter boxes and equipment/circuits outside or remote from the domestic
environment e.g. circuits in sheds, garden houses and free-standing garages, or
circuits using underground wiring e.g. garden lighting, pool-pump…
THIS DEVICE IS ONLY SUITABLE FOR MEASUREMENTS UP TO
600 V IN
CAT III
.
