Never exceed the limiting values of protection indicated in the specifications (
§ 4).
When the order of magnitude of the value to be measured is unknown, make sure that the
starting measurement range is the highest possible, or choose the automatic range selection
mode.
Before changing the function, disconnect the wires for measuring the external circuit. When
measuring current and / or voltage, even if low, remember that the circuits may be live with
respect to earth, at a voltage that is dangerous for the operator.
Never carry out resistance measurements on a live circuit.
1.4.4
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 unfavourable conditions.
•
The unit has been subjected to severe stress during transportation.
1.4.5
Definitions
Definition of the installation category
This is also known as the overvoltage category.
It is the classification of the installation according to standard limits for transient overvoltag-
es (standard CEI 664).
Table of symbols used
Symbol
Description
Earth point
Complies with European Union directives
