HT instruments VEGA78 - Manual (Page 6)

VEGA78
EN - 4
1.3. DURING USE
Please read carefully the below points:
CAUTION
Should you fail to keep to the prescribed instructions you could damage the
instrument and/or its components or endanger your safety.
 Do not touch any unused terminal when the meter is connected to the circuit on test.
 When measuring current, other currents located near the leads may affect the
measuring accuracy.
 When measuring current, always position the wire in the very middle of the jaws in
order to obtain the highest accuracy.
 A measured value remains constant if the "HOLD" function is active. Should you notice
that the measured value remains unchanged, disable the “HOLD” function.
1.4. AFTER
USE
 After use, turn off the instrument by pressing ON/OFF key for a few seconds.
 If you expect not to use the instrument for a long time please keep to the storage
instructions described at § 3.4.
1.5. MEASURING
(OVERVOLTAGE) CATEGORIES DEFINITIONS
IEC / EN61010-1: Safety requirements for electrical equipment for measurement, control
and laboratory use, Part 1: General requirements, gives a definition of measuring
category, usually called overvoltage category. § 6.7.4: Measuring circuits:
(OMISSIS)
Circuits are divided into the following measurement categories:
 Measurement category IV is for measurements performed at the source of the low-
voltage installation.
Examples are electricity meters and measurements on primary overcurrent protection
devices and ripple control units.
 Measurement category III is for measurements performed in the building installation.
Examples are measurements on distribution boards, circuit breakers, wiring, including
cables, bus-bars, junction boxes, switches, socket-outlets in the fixed installation, and
equipment for industrial use and some other equipment, for example, stationary
motors with permanent connection to fixed installation.
 Measurement category II is for measurements performed on circuits directly
connected to the low voltage installation.
Examples are measurements on household appliances, portable tools and similar
equipment.
 Measurement category I is for measurements performed on circuits not directly
connected to MAINS.
Examples are measurements on circuits not derived from MAINS, and specially
protected (internal) MAINS-derived circuits. In the latter case, transient stresses are
variable; for that reason, the norm requires that the transient withstand capability of the
equipment is made known to the user.