Directives CE
A
7
A.4.5
Making measurements
Measuring wires and leads must be in good condition and must be replaced if their insulation appears defective (insulation
cut, burned, etc.).
Never exceed the protection value limits indicated in the specifications.
Before changing function, disconnect the measuring wires from the external circuit. When voltage measurements are
being made, even weak ones, keep in mind that the circuits may feature a dangerous voltage for the operator compared to
the ground.
Do not make any measurements when the device is linked up to another device using the USB link or when the batteries
are being charged.
A.4.6
Unusual faults and stresses
Whenever it is believed that the protection has been damaged, switch off the unit and ensure that it is not used
prematurely.
The protection may have been damaged if, for example:
There is obvious damage to the unit.
The unit is no longer able to make accurate measurements.
The unit has been stored under unfavorable conditions.
The unit has been subjected to severe stress during transportation.
A.4.7
Definitions
A.4.7.1
Definition of the category and degree of pollution
CAT II 60V:
This notion of categories determines the maximum voltage which can be applied to the measuring inputs (it is also
referred to as the overvoltage category). For the TC621, the ceiling overvoltage is (DC or AC)
POL 2°:
The notion of pollution determines the clearance between circuits. Degree 2 authorizes temporary conductivity caused by
condensation.
A.4.7.2
Table of symbols used
Symbol
Description
Warning: see accompanying documents
Earth point
Complies with European Union directives
60V
CAT II Pol 2
Category II, Pollution 2.
Maximum common mode voltage compared with the ground = 60 V
Do not discard. See chapter Used devices (see section A.3.3)
Do not discard. See chapter Used devices (see section A.3.3)
