HT Instruments HT6 Bedienungsanleitung Seite 22

1.1. PRELIMINARY INSTRUCTIONS
• This instrument has been designed for use in environments of pollution degree 2.
• It can be used for VOLTAGE measurements on installations with measurement CAT IV
600V – CAT III 690V. For a definition of measurement categories, see § 1.4.
• We recommend following the normal safety rules devised by the procedures for
carrying out operations on live systems and using the prescribed PPE to protect the
user against dangerous currents and the instrument against incorrect use.
• Do not test circuits exceeding the specified voltage limits.
• Make sure the batteries are installed correctly
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.
• When the instrument is connected to the circuit being tested, do not touch any unused
terminal.
• Avoid measuring continuity if external voltages are present.
1.3. AFTER USE
• 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, 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.
CAUTION
EN - 3
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