IEC 60947-3:2015 pdf download – Low-voltage switchgear and controlgear – Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units.
4.3.1 .3 Rated impulse withstand voltage (U imp ) Subclause 4.3.1 .3 of IEC 60947-1 applies. 4.3.2 Currents An equipment is defined by the following currents. 4.3.2.1 Conventional free air thermal current (I th ) Subclause 4.3.2.1 of IEC 60947-1 applies. 4.3.2.2 Conventional enclosed thermal current (I the ) Subclause 4.3.2.2 of IEC 60947-1 applies. 4.3.2.3 Rated operational currents (I e ) (or rated operational powers) Subclause 4.3.2.3 of IEC 60947-1 applies. 4.3.2.4 Rated uninterrupted current (I u ) Subclause 4.3.2.4 of IEC 60947-1 applies. 4.3.3 Rated frequency Subclause 4.3.3 of IEC 60947-1 applies. 4.3.4 Rated duty The rated duties considered as normal are as follows. 4.3.4.1 Eight-hour duty Subclause 4.3.4.1 of IEC 60947-1 applies. 4.3.4.2 Uninterrupted duty Subclause 4.3.4.2 of IEC 60947-1 applies. 4.3.5 Normal load and overload characteristics 4.3.5.1 Ability to withstand motor switching overload currents See Annex A. 4.3.5.2 Rated making capacity Subclause 4.3.5.2 of IEC 60947-1 applies with the following additions. The rated making capacity is stated by reference to the rated operational voltage and rated operational current and to the utilization category according to Table 3. Not applicable to AC-20 or DC-20 equipment. 4.3.5.3 Rated breaking capacity Subclause 4.3.5.3 of IEC 60947-1 applies with the following additions.
The rated breaking capacity is stated by reference to the rated operational voltage and rated operational current and to the utilization category according to Table 3. Not applicable to AC-20 or DC-20 equipment. 4.3.6 Short-circuit characteristics 4.3.6.1 Rated short-time withstand current (I cw ) The rated short-time withstand current of a switch, a disconnector or a switch-disconnector is the value of short-time withstand current, assigned by the manufacturer, that the equipment can carry without any damage under the test conditions of 8.3.5.1 . The value of the rated short-time withstand current shall be not less than twelve times the maximum rated operational current and, unless otherwise stated by the manufacturer, the duration of the current shall be 1 s. For a.c., the value of the current is the r.m.s. value of the a.c. component and it is assumed that the highest peak value likely to occur does not exceed n times this r.m.s. value, the factor n being given by Table 1 6 of IEC 60947-1 .
5 Product information 5.1 Nature of information Subclause 5.1 of IEC 60947-1 applies as appropriate for a particular design. 5.2 Marking 5.2.1 Each equipment shall be marked in a durable and legible manner with the following data. The markings for a), b) and c) below shall be on the equipment itself or on a name-plate or name-plates attached to the equipment, and shall be located at a place such that they are legible from the front after mounting the equipment in accordance with the manufacturer’s instructions. a) Indication of the open and closed position. The open and closed position shall be respectively indicated by the graphical symbols 6041 7-IEC-5007 and 6041 7-IEC-5008 of IEC 6041 7-2 (see 7.1 .6.1 of IEC 60947-1 ). b) Suitability for isolation. The appropriate symbols of Table 1 shall be used. c) Additional marking for disconnectors. Devices of utilization category AC-20A, AC-20B, DC-20A and DC-20B shall be marked “Do not operate under load”, unless the device is interlocked to prevent such operation. NOTE Symbols of the various types of equipment are given in Table 1 .
5.3 Instructions for installation, operation and maintenance Subclause 5.3 of IEC 60947-1 applies. 6 Normal service, mounting and transport conditions Clause 6 of IEC 60947-1 applies with the following addition. Pollution degree (see 6.1 .3.2 of IEC 60947-1 ). Unless otherwise stated by the manufacturer, the equipment is intended for installation under environmental conditions of pollution degree 3. 7 Constructional and performance requirements 7.1 Constructional requirements Subclause 7.1 of IEC 60947-1 applies, with the following additions.
The test speed for the making operations specified in 8.3.6.2 shall be determined as follows. a) The equipment shall be operated 1 5 times manually under no-load conditions in accordance with the manufacturer’s instructions, 5 times by each of three persons. The velocity of the hand actuator at the instant of contact closure of the last closing contact shall be determined by oscillographic or other appropriate means at any convenient part of the device. The point at which the measurement is made and the velocity at the measurement point shall be stated in the test report. The mean velocity shall be determined after deleting the highest and lowest values. b) The test apparatus shall ensure that the equipment under test fully closes and that there is no impediment to the free closing movement of the device. The actual test speed shall not exceed the mean velocity determined according to a). The mass of the moving parts of the test apparatus (without the equipment under test) shall be 2 kg ± 1 0 %.