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XL423 - XL424
EN - 3
1.2 DURING USE
Carefully read the below recommendations and instructions:
CAUTION
No compliance with warnings and/or instructions may cause damage to
the tester or its components or injure the operator
During a measurement never touch any unused terminal.
1.3 AFTER USE
If you expect not to use the instrument for a long period of time remove the batteries
and strictly follow the indications at § 9.2.
1.4 OVERVOLTAGE CATEGORIES - DEFINITIONS
IEC/EN61010-1 (Safety requirements for electrical equipment for measurement, control
and laboratory use, Part 1: General requirements) defines what a measurement category
(usually called “overvoltage category”) is. At § 6.7.4: Measuring circuits you read:
(OMISSIS)
Circuits are divided into the following measurement categories:
Measurement category IV is for measurements performed at the source of low
voltage installations.
Examples are electricity instruments 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 withstanding capability of the equipment is made
known to the user.