AMETEK MX CTSH - Manual (Page 102)

California Instruments Revision H 10
2
User Manual MX Series CTSH Compliance Test System
9.4 Test Levels
In Annex B of the draft standard, the EUT operating environment classifications are defined based on IEC
61000-2-4. The classifications are as follows:
Class Environment
Class 1 Applies to protected supplies with compatibility levels lower than public network levels.
It relates to the use of equipment, which is very sensitive to disturbances in the
power supply, for instance the instrumentation of technological laboratories, some
automation and protection equipment, some computers etc. This equipment is
normally supplied by protected supplies such as uninterruptible power supplies, filers
or surge suppressors.
Class 2 Applies to points of common coupling (PCCs for consumer systems) and in-plant
points of common coupling (IPCs) in the industrial environment in general. The
compatibility levels in this class are identical to those of public networks.
Class 3 Applies only to IPCs in industrial environments. It has higher compatibility levels than
those of class 2 for some disturbance phenomena. This class should be considered
when any of the following conditions are met:
- a major part of the load is fed through converters
- welding machines are present
- large motors are frequently started
- loads vary rapidly
Test levels are specified for class 2 and 3 only. Class X test levels may be defined by specific product
standards.
Environment Class Unom (Nominal Voltage) Unom + 10 % Unom - 10 %
Class 1 no test required no test required no test required
Class 2 ± 8 % Unom - 8 % Unom + 8 % Unom
Class 3 ± 12 % Unom -12 % Unom + 12 % Unom
Class X Open but must be higher than
Level 2 Open but must be
higher than Level 2 Open but must be
higher than Level 2