HT EQUITEST, User Manual

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EQUITEST
EN - 3
1.2 DURING USE
Please carefully read the following recommendations and instructions:
CAUTION
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