IEC 60252-2-2003 pdf – AC motor capacitors – Part 2: Motor start capacitors.
1 General 1.1 Scope and object This International Standard applies to motor start capacitors intended for connection to windings of asynchronous motors supplied from a single-phase system having the frequency of the mains. This standard covers impregnated or unimpregnated metallized motor start capacitors having a dielectric of paper or plastic film, or a combination of both and electrolytic motor start capacitors with non-solid electrolyte, with rated voltages up to and including 660 V. 1.2 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. IEC 60068-2-6:1995, Environmental testing – Part 2: Tests – Test Fc: Vibration (sinusoidal) IEC 60068-2-14:1984, Environmental testing – Part 2: Tests – Test N: Change of temperature IEC 60068-2-20:1979, Environmental testing – Part 2: Tests – Test T: Soldering IEC 60068-2-21:1999, Environmental testing – Part 2-21: Tests – Test U: Robustness of terminations and integral mounting devices IEC 60068-2-78:2001, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady state IEC 60112:1979, Method for determining the comparative and the proof tracking indices of solid insulating materials under moist conditions IEC 60309-1:1999, Plugs, socket-outlets and couplers for industrial purposes – Part 1: General requirements IEC 60529:1989, Degrees of protection provided by enclosures (IP Code) IEC 60695-2-10:2000, Fire hazard testing – Part 2-10: Glowing/hot-wire based test methods – Glow-wire apparatus and common test procedure IEC 60695-2-11:2000, Fire hazard testing – Part 2-11: Glowing/hot-wire based test methods – Glow-wire flammability test method for end-products ISO 4046: Paper, board, pulps and related terms – Vocabulary
1.3 Definitions For the purposes of this document, the following definitions apply. 1.3.1 motor running capacitor power capacitor which, when used in conjunction with an auxiliary winding of a motor, assists the motor to start and improves the torque under running conditions NOTE The running capacitor is usually connected permanently to the motor winding and remains in circuit throughout the running period of the motor. During the starting period, if it is in parallel with the starting capacitor, it helps to start the motor. 1.3.2 motor starting capacitor power capacitor which provides a leading current to an auxiliary winding of a motor and which is switched out of circuit once the motor is running 1.3.3 metal foil capacitor capacitor, the electrodes of which consist of metal foils or strips separated by a dielectric 1.3.4 metallized capacitor capacitor, in which the electrodes consist of a metallic deposit on the dielectric 1.3.5 self-healing capacitor capacitor, the electrical properties of which, after local breakdown of the dielectric, are rapidly and essentially self-restored 1.3.6 discharge device of a capacitor device which may be incorporated in a capacitor, capable of reducing the voltage between the terminals effectively to zero, within a given time, after the capacitor has been disconnected from a network 1.3.7 continuous operation operation with no time limit within the normal life of the capacitor 1.3.8 intermittent operation operation in which periods with the capacitor energized are followed by intervals during which the capacitor is unenergized 1.3.9 starting operation special type of intermittent operation in which the capacitor is energized for only a very short period while the motor is accelerating to rated speed 1.3.10 rated duty cycle rated value indicating the rate of intermittent or starting duty for which a capacitor is suitable. It is specified by the duty cycle duration, in minutes, and the percentage of the time during which the capacitor is energized
1.3.11 duty cycle duration total time of one energized and one unenergized interval during the intermittent operation 1.3.12 relative operation time percentage of the cycle duration in which the capacitor is energized 1.3.13 capacitor for continuous and starting operation capacitor designed to operate at one voltage when in continuous operation and at a different (usually higher) voltage when in starting operation 1.3.14 minimum permissible capacitor operating temperature minimum permissible temperature on the outside of the case at the moment of switching on the capacitor 1.3.15 maximum permissible capacitor operating temperature (t c ) maximum permissible temperature of the hottest area of the outside of the capacitor case during operation 1.3.16 rated voltage of a capacitor (U N ) r.m.s. value of the alternating voltage for which the capacitor has been designed 1.3.17 maximum voltage maximum r.m.s. voltage permissible at the starting capacitor terminals between the point of starting and the instant at which the capacitor is disconnected 1.3.18 rated frequency of a capacitor (f N ) highest frequency for which the capacitor has been designed