1.2 DURING USE
Please carefully read the following recommendations and instructions:
The Failure to observe the warnings and/or instructions may damage the
accessory 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 accessory 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 accessory is
protected, excessive voltage could cause damage
1.3 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
CAUTION
EN - 3
EQUITEST