HT instruments T2100 - Manual (Page 4)

T2000-T2100
EN – 3
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.
 Operate the clamp lever twice before switching on the instrument, to make sure that the
clamp jaws are completely closed.
 When switching on the instrument, DO NOT operate the clamp lever and do not clamp
any cable.
 Avoid measuring resistance if external voltages are present. Even if the instrument is
protected, excessive voltage could cause malfunctions.
 During current measurement (T2000), any other current near the clamp may affect
measurement precision.
 When measuring current (T2000), always put the conductor as near as possible to the
middle of the clamp jaw, to obtain the most accurate reading.
 While measuring, if the value of the quantity being measured remains unchanged, check
if the HOLD function is enabled.
CAUTION
If the symbol “ ” is displayed during use, interrupt testing, disconnect the
instrument from the system, switch off the instrument and replace its batteries
(see § 5.2).
1.3. AFTER USE
 When measurements are completed, switch off the instrument by pressing the
multifunction key “1” (see § 4.4).
 If the instrument is not to be used for a long time, remove the batteries.
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 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 on installations inside
buildings.
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 standard requires that the transient withstand capability of the equipment
is made known to the user.