This standard is applicable to a.c. contactors and/or contactor-based motor starters designed for indoor installation and operation at frequencies up to and including 60 Hz on systems having voltages above 1 000 V but not exceeding 12 000 V. It is applicable only to three-pole contactors and starters for use in three-phase systems, and single-pole contactors and starters for use in single-phase systems. Two-pole contactors and starters for use in single-phase systems are subject to agreement between manufacturer and user. Contactors and/or starters dealt with in this standard are not normally designed to interrupt short-circuit currents. Therefore, suitable