AMETEK CTS 3.0 - Manual (Page 123)

User Manual Compliance Test System 3.0
119
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
Testing is not recommended for Class 1 equipment. Test level X specifications are to be agreed
upon by the manufacturer and user. Test Levels for environmental Class 2 and 3 equipment are
defined by the generic standard. A user class X (user) with test level equal or higher than those of
level 2 may be set as well.