HT instruments MACROTEST G3 - Manual (Page 5)

MACROTESTG3 - COMBIG3
EN - 4
1.2. DURING USE
Please carefully read the following recommendations and instructions:
CAUTION
Failure to comply with the caution notes and/or instructions may damage
the instrument and/or its components or be a source of danger for the
operator.
 Before changing function, disconnect the test leads from the circuit under test.
 When the instrument is connected to the circuit under test, never touch any terminal,
even if unused.
 Avoid measuring resistance if external voltages are present. Even if the instrument is
protected, excessive voltage could cause damage.
 While measuring current, place the clamp jaws as far as possible from the conductors
not involved in the measurement, as the magnetic field they produce could interfere
with the measuring operations and place the conductor as much as possible in the
center of the jaws to maximize accuracy.
1.3. AFTER
USE
When measurements are completed, turn off the instrument by pressing and holding the
ON/OFF key for some seconds. If the instrument is not to be used for a long time, remove
the batteries and follow the instructions given in § 3.4.
1.4.
DEFINITION OF MEASUREMENT (OVERVOLTAGE) CATEGORY
Standard "IEC/EN61010-1: Safety requirements for electrical equipment for measurement,
control and laboratory use, Part 1: General requirements” defines what measurement
category, commonly called overvoltage category, is. § 6.7.4: Measured circuits, reads:
circuits are divided into the following measurement categories:
 Measurement category IV is for measurements performed at the source of a 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 on installations inside
buildings.
Examples are measurements on distribution boards, circuit breakers, wiring, including
cables, bus-bars, junction boxes, switches, socket-outlets in 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 standard requires that the transient withstand capability of
the equipment is made known to the user.