Motor starter configurations
From Electrical Installation Guide
Different configurations of switchgear and control-gear are commonly proposed. Some examples are shown on Figure N66.
Fig. N66: The various functions and their combinations forming a motor starter
The different applicable standards are listed on Figure N67.
|IEC 60947-1||Low-voltage switchgear and controlgear – General rules|
|IEC 60947-4-1||Contactors and motor-starters –Electromechanical contactors and motor-starters|
|IEC 60947-4-2||Contactors and motor-starters – AC semiconductor motor controllers and starters|
|IEC 60947-6-2||Multiple function equipment – Control and protective switching devices (or equipment) (CPS)|
|IEC 61800||Adjustable speed electrical power drive systems|
Fig. N67: Applicable standards
Different utilization categories have been defined for contactors in IEC 60947-4-1. The selection relative to asynchronous motor control is given in Figure N68.
|AC-1||Non-inductive or slightly inductive loads, resistance furnaces|
|AC-2||Slip-ring motors: starting, switching off|
|AC-3||Squirrel-cage motors: starting, switching off motors during running|
|AC-4||Squirrel-cage motors: starting, plugging(1), inching(2)|
(1) By plugging is understood stopping or reversing the motor rapidly by reversing motor primary connections while the motor is running.
(2) By inching (jogging) is understood energizing a motor once or repeatedly for short periods to obtain small movements of the driven mechanism
Fig. N68: Different categories of AC contactors used for asynchronous motor control