During Use; After Use; Definition Of Measurement (Overvoltage) Category - HT HT77N Manual De Instrucciones

1.2. DURING USE

Please carefully read the following recommendations and instructions:
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 switching on the clamp, remove the conductor from the clamp jaw.
When the instrument is connected to the circuit under test, do not touch any unused
terminal.
During current measurement, any other current near the clamp may affect
measurement precision.
When measuring current, always put the conductor as near as possible to the middle of
the clamp jaw, as described in § 0, to obtain the most accurate reading.
While measuring, if the value or the sign of the quantity being measured remain
unchanged, check if the HOLD or PEAK HOLD function is enabled.

1.3. AFTER USE

When measurement is complete, switch off the clamp.
If the instrument is not to be used for a long time, remove the battery.

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. In § 6.7.4: Measured circuits, circuits
are divided into the following measurement categories:
(OMISSIS)
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.
CAUTION
EN - 3
HT77N