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.