Motor contactors work as a protection device for the motor. Two-pole, three-pole, and four-pole devices are commonly available. A three-pole motor contactor consists of a 120 V or 240 V coil. International Engineering Commission (IEC) sizes are lettered and range from B to G. A 4-pole motor contactor has a 40 amp, 240 V coil with a wider current selection range. Specifications include 50 - 60 Hz dual frequency, AC: 8-1.1of nominal voltage, and DC: 7-1.25 of nominal voltage in standard and low consumption versions. AC motor starters consist of an overload protection circuit and a motor contactor to ensure that during motor startup, extra current is not drawn. C motor starters are used to turn on/off both motor-controlled equipments and electric motors. AC motor starters also provide protection against low-voltage and power interruption in wires. DC motor starters of 70 W enable fast and simple connection to 24 VDC motors and their sensors. Motor contactors have DC motor sensors which are one of three types: direct starter, twin direct starter, and reversing starter.

Motor contactors are used in motor control, mercury switch replacement, ramp timing control, and various industrial applications to provide overload protection.Guidelines for motor contactors are maintained by National Electric Manufacturers Association (NEMA) and the International Engineering Commission (IEC).The NEMA rating indicates the horsepower and continuous current rating at the rated voltages. The IEC rating indicates thermal current ratings.
Main Contactor
AC & DC operated
Integrated auxiliary contacts
Screw fixing and snap fitting (35 mm DIN rail) up to 45 kW
Range from 4 to 110 kW (AC 3, 380/415V)
Finger proof (VBG 4)
Accessories
Front mounted single pole additional auxiliary contacts (1 NO or 1 NC)
Side mounted additional auxiliary contacts (1 NO/1 NC)
Mechanical interlock
Suppressors (RC and varistor)
Pneumatic timer modules
Link modules MPCB - Motor contactor
Approved Standards
UL
ICE 947-4-1
VDE 0660
EN 60947-4-1