scope:

The requirements in this Outline of Investigation are for verification of short-circuit tests to be conducted on Type ²2² coordinated electromechanical motor controllers as defined by and in accordance with the Standard for Low Voltage Switchgear and Controlgear, Part 4: Contactors and Motor-Starters, International Electrotechnical Commission (IEC) Publication 947-4-1.

These requirements cover electromechanical motor controllers, such as manually or magnetically operated contactors with or without thermal or solid state overload relays, combination motor controllers with discrete components, and starters that are provided with short circuit protective devices, that have been investigated for compliance with the requirements in the Standard for Industrial Control Equipment, UL 508, and where the main contact voltage rating does not exceed 1000 V ac or 1500 V dc.

The requirements in this Outline of Investigation are applicable only to those specific motor controllers and short circuit protective devices (SCPD) which have been coordinated together by the manufacturer.