Switch-Disconnectors
Introduction
A switch-disconnector is a control device that can be used to open and close a circuit under normal operating conditions. The switch-disconnector can make or break its rated current. For an overload or a short-circuit, it must be protected by an upstream device, in compliance with installation standards.
Switch-Disconnector Utilization Category
Depending on the rated operational current and the mechanical durability (A for frequent operation or B for infrequent operation), standard IEC/EN 60947-3 defines the utilization categories as shown in the following table. ComPacT NSXm NA switch-disconnectors comply with utilization categories AC-21A or AC-22A up to 160 A and AC-23A up to 100 A.
|
Utilization categories |
||
|---|---|---|
|
Infrequent operation |
Frequent operation |
Characteristics |
|
AC-21B |
AC-21A |
Switching of resistive loads including moderate overloads (cos φ = 0.95) |
|
AC-22B |
AC-22A |
Switching of mixed resistive and inductive loads, including moderate overloads (cos φ = 0.65) |
|
AC-23B |
AC-23A |
Switching of motor loads or other highly inductive loads (cos φ = 0.45 or 0.35) |