IEC 60470:2000 applies to a.c. contactors and/or contactor-based motor starters designed for indoor use, operating at frequencies up to and including 60 Hz, on systems with voltages exceeding 1,000 V but not exceeding 12,000 V. It specifically addresses three-pole contactors and starters intended for three-phase systems, as well as single-pole contactors and starters for single-phase systems. Two-pole contactors and starters for single-phase systems must be agreed upon by the manufacturer and user.
The contactors and starters covered by this standard are typically not designed to interrupt short-circuit currents. Therefore, appropriate short-circuit protection (see 3.4.1 1 0.1 2 and note 2 below) must be included in the installation, though it is not necessarily part of the contactor or starter itself.
In this context, the standard outlines requirements for:
- Contactors used with overload and/or short-circuit protective devices (SCPD).
- Starters associated with separate short-circuit protective devices and/or integrated overload protective devices.
- Contactors or starters that are combined, under specific conditions, with their own short-circuit protective devices. Such combinations, like combination starters (see 3.4.1 1 0.9), are rated as complete units.
This standard also covers contactors designed for opening and closing electrical circuits, and when paired with suitable relays, for protecting these circuits against operational overloads.
The standard is applicable to the operating devices of contactors and their auxiliary equipment. It addresses motor starters that are intended to start and accelerate motors to their normal speed, ensure continuous operation, disconnect the motor supply, and provide protections against operational overloads.
Included types of motor starters are:
- Direct-on-line starters
- Reversing starters
- Two-direction starters
- Reduced kVA (voltage) starters
- Auto-transformer starters
- Rheostatic starters
- Reactor starters
Motor starters that rely on thermal electrical relays for motor protection, in compliance with IEC 60255-8, or thermal protective devices incorporated in motors as outlined in IEC 60034-11, may not meet all relevant requirements of this standard. Overload relays for starters, including those based on solid-state technology, are also addressed.
This standard does not apply to:
- Circuit-breaker-based motor starters
- Single-pole operation of multi-pole contactors or starters
- Two-step auto-transformer starters designed for continuous operation in the starting position
- Unbalanced rheostatic rotor starters, where resistances differ across phases
- Equipment designed for both starting and speed adjustment
- Liquid starters and those of the “liquid-vapor” type
- Semiconductor contactors and starters that utilize semiconductor contactors in the main circuit
- Rheostatic stator starters
- Contactors or starters designed for specialized applications
Additionally, this standard does not cover components within contactors and contactor-based motor starters that have separate specifications.
NOTE 1: Thermal electrical relays are addressed by IEC 60255-8.
NOTE 2: High-voltage current-limiting fuses are covered by IEC 60282-1 and IEC 60644.
NOTE 3: Metal-enclosed switchgear and controlgear rated above 1 kV and up to 52 kV are covered by IEC 60298.
NOTE 4: Disconnectors and earthing switches are addressed by IEC 60129.
NOTE 5: High-voltage switches rated above 1 kV and below 52 kV are covered by IEC 60265-1.
The objectives of this standard are to outline:
a) The characteristics of contactors, starters, and associated equipment.
b) The conditions that contactors and starters must meet regarding:
- Their operation and behavior,
- Their dielectric properties,
- The protection levels offered by their enclosures, where applicable,
- Their construction,
- The interactions between various components in combinations, such as SCPD coordination.
c) The tests required to verify compliance with these conditions and the methods for conducting these tests.
d) The information that must accompany the equipment or be included in the manufacturer’s documentation.
