Low-voltage switchgear and controlgear—Part 4-1:Contactors and motor-starters—Electromechanical contactors and motor-starters(Including motor protector)
1 Scope and object
1.1 Scope
This part applies to the types of equipment listed in 1.1 and 1.2 whose main contacts are intended to be connected to circuits the rated voltage of which does not exceed 1,000 V a.c. or 1,500 V d.c.
Starters and/or contactors dealt with in this part are not normally designed to interrupt short-circuit currents. Therefore, suitable short-circuit protection (see 9.3.4) forms part of the installation but not necessarily of the contactor or the starter.
In this context, this part gives requirements for:
——contactors associated with overload and/or short-circuit protective devices;
——starters associated with separate short-circuit protective devices and/or with separate short-circuit and integrated overload protective devices;
——contactors or starters combined, under specified conditions, with their own short-circuit protective devices. Such combinations, e.g. combination starters or protected starters are rated as units.
For circuit-breakers and fuse-combination units used as short-circuit protective devices in combination starters and in protected starters, the requirements of GB 14048.2 and GB 14048.3 respectively apply.
Equipment covered by this part is as follows.
1.1.1 AC and DC contactors
AC and DC contactors intended for closing and opening electric circuits and, if combined with suitable relays (see 1.1.2), for protecting these circuits against operating overloads which may occur therein.
Note: For contactors combined with suitable relays and which are intended to provide short-circuit protection, the relevant conditions specified for circuit-breakers (GB 14048.2) additionally apply.
This part applies also to the actuators of contactor relays and to the contacts dedicated exclusively to the coil circuit of a contactor.
Contactors or starters with an electronically controlled electromagnet are also covered by this part.
1.1.2 AC motor-starters
AC motor-starters intended to start and accelerate motors to normal speed, to ensure continuous operation of motors, to switch off the supply from the motor and to provide means for the protection of motors and associated circuits against operating overloads.
For overload relays for starters, including those based on electronic technology with or without extended functions according to Annex H, the requirements of this part apply.
Note: Overload relays based on electronic technology are also called “motor protector” or “motor management system”.
1.1.2.1 Direct-on-line (full voltage) a.c. starters
Direct-on-line starters intended to start and accelerate a motor to normal speed, to provide means for the protection of the motor and its associated circuits against operating overloads, and to switch off the supply from the motor.
This part applies also to reversing starters.
1.1.2.2 Reduced voltage a.c. starters
Reduced voltage a.c. starters intended to start and accelerate a motor to normal speed by connecting the line voltage across the motor terminals in more than one step or by gradually increasing the voltage applied to the terminals, to provide means for the protection of the motor and its associated circuits against operating overloads, and to switch off the supply from the motor.
Automatic change-over devices may be used to control the successive switching operations from one step to the others. Such automatic change-over devices are, for example, time-delay contactor relays or specified time all-or-nothing relays, under-current devices and automatic acceleration control devices (see 5.10).
1.1.2.2.1 Star-delta starters
Star-delta starters intended to start a three-phase motor in the star connection, to ensure continuous operation in the delta connection, to provide means for the protection of the motor and its associated circuits against operating overloads, and to switch off the supply from the motor.
The star-delta starters dealt with in this part are not intended for reversing motors rapidly and, therefore, utilization category AC-4 does not apply.
Note: In the star connection, the current in the line and the torque of the motor are about one-third of the corresponding values for delta connection. Therefore, star-delta starters are used when the inrush current due to the starting is to be limited, or when the driven machine requires a limited torque for starting. Figure 1 of this part indicates typical curves of starting current, of starting torque of the motor and of torque of the driven machine.
1.1.2.2.2 Two-step auto-transformer starters
Two-step auto-transformer starters, intended to start and accelerate an a.c. induction motor from rest with reduced torque to normal speed and to provide means for the protection of the motor and its associated circuits against operating overloads, and to switch off the supply from the motor.
This part applies to auto-transformers which are part of the starter or which constitute a unit specially designed to be associated with the starter.
Auto-transformer starters with more than two steps are not covered by this part.
The auto-transformer starters dealt with in this part are not intended for inching duty or reversing motors rapidly and, therefore, utilization category AC-4 does not apply.
Note: In the starting position, the current in the line and the torque of the motor related to the motor starting with rated voltage are reduced approximately as the square of the ratio (starting voltage):(rated voltage). Therefore, auto-transformer starters are used when the inrush current due to the starting is to be limited or when the driven machine requires a limited torque for starting. Figure 2 of this part indicates typical curves of starting current, of starting torque of the motor and of torque of the driven machine.
1.1.2.3 Rheostatic rotor starters
Starters intended to start an a.c. induction motor having a wound rotor by cutting out resistors previously inserted in the rotor circuit, to provide means for the protection of the motor and its associated circuits against operating overloads and to switch off the supply from the motor.
In the case of asynchronous slip-ring motors (wound-rotors), the highest voltage between open slip-rings is not greater than twice the insulation voltage of the switching devices inserted in the rotor circuit (see 5.3.1.1.2).
Note: This requirement is based on the fact that the electric stresses are less severe in the rotor than in the stator and are of short duration.
This part applies also to starters for two directions of rotation when reversal of connections is made with the motor stopped (see 5.3.5.5). Operations including inching and plugging necessitate additional requirements and are subject to agreement between manufacturer and user.
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2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 755-2008 Rotating electrical machines - Rating and performance (IEC 60034-1: 2004, IDT)
GB/T 2421.1-2008 Environmental testing for electric and electronic products - General and guidance (IEC 60068-1: 1988, IDT)
GB/T 2423.1-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Tests A: Cold (IEC 60068-2-1: 2007, IDT)
GB/T 2423.2-2008 Environmental testing for electric and electronic products - Part 2: Test methods - Test B: Dry heat (IEC 60068-2-2: 2007, IDT)
GB/T 2423.4-2008 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle) (IEC 60068-2-30: 2005, IDT)
GB/T 2423.5-1995 Environmental testing for electric and electronic products - Part 2: Test methods - Test Ea and guidance: Shock (IEC 60068-2-27: 1987, IDT)
GB/T 2423.10-2008 Environmental testing for electric and electronic products - Part 2: Tests methods - Test Fc: Vibration (sinusoidal) (IEC 60068-2-6:1995, IDT)
GB/T 2423.18-2000 Environmental testing for electric and electronic products - Part 2: Tests - Test Kb: Salt mist, cyclic (sodium chloride solution) (IEC 60068-2-52: 1996, IDT)
GB/T 2828.1-2003 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO 2859-1:1999, IDT)
GB/T 4798 (all series) Environmental conditions existing in the application of electric and electronic products (IEC 60721-3, all series)
GB 4824-2004 Industrial, scientific and medical (ISM) radio-frequency equipment - Electromagnetic disturbance characteristics - Limits and methods of measurement (CISPR 11:2003, IDT)
GB/T 11021-2007 Electrical insulation - Thermal classification (IEC 60085:2004, IDT)
GB 14048.1-2006 Low-voltage switchgear and controlgear - Part 1: General rules (IEC 60947-1:2001, MOD)
GB 14048.2-2008 Low-voltage switchgear and controlgear - Part 2: Circuit-breakers (IEC 60947-2:2006, IDT)
GB 14048.3-2008 Low-voltage switchgear and controlgear - Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units (IEC 60947-3:2005, IDT)
GB 14048.5-2008 Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching element - Electromechanical control circuit devices (IEC 60947-5-1: 2003, MOD)
GB 14048.16-2006 Low-voltage switchgear and controlgear - Part 8: Control units for built-in thermal protection(PTC) for rotating electrical machines (IEC 60947-8: 2003, MOD)
GB/T 16855.1-2008 Safety of machinery - Safety-related parts of control systems - Part 1: General principles for design (ISO 13849-1: 2006, IDT)
Foreword i
1 Scope and object
2 Normative references
3 Terms and definitions
4 Classification
5 Characteristics of contactors and starters
6 Product information
7 Normal service, mounting and transport conditions
8 Constructional and performance requirements
9 Tests
Annex A (Normative) Marking and identification of terminals of contactors and associated overload relays
Annex B (Normative) Special tests
Annex C Void
Annex D (Informative) Submission of items subject to agreement between manufacturer and user
Annex E (Informative) Examples of control circuit configurations
Annex F (Normative) Requirements for auxiliary contacts linked with power contacts (mirror contacts)
Annex G (Informative) Rated operational currents and rated operational powers of switching devices for electrical motors
Annex H (Informative) Extended functions within electronic overload relays
Annex I (Informative) AC1 contactors for use with semiconductor controlled motor loads
Annex J (Informative) Communication function of electronic overload relay
Annex K (Normative) Procedure to determine data for electromechanical contactors used in functional safety applications
Annex L (Informative) Differences between this part and IEC 60947-4-1:2009 (Ed.3.0) and the reasons
Annex M Informative Differences between this part and GB 14048.4-2003 and the reasons
Annex Q (Normative) Special tests - damp heat, salt mist, vibration and shock
References
