IEEE C37.20.1-2015 pdf free.IEEE Standard for Metal-Enclosed Low-Voltage (1 000 Vac and below, 3200 Vdc and below) Power Circuit Breaker Switchgear.
metal-enclosed poser switchgear (ME): A switchgear assembly completely enclosed on all sides and top with sheet metal (except for ventilating openings and inspection windows) containing primary power circuit switching or interrupting devices, or both. with buses and connections. The assembly may include control and auxiliary devices. Access to the interior of the enclosure is provided by doors or removable covers, or both.
production tests: Tests made for quality control by the manufacturer on every device or representative samples. or on parts or materials as required to verify during production that the product meets the design specifications and applicable standards.
NOTE—Production tests are sometimes called routine tests.
sw itchgcar: A general term covering switching and interrupting devices and their combination with associated control, instruments, metering, protective, and regulating devices; also assemblies of these devices with associated interconnections, accessories, and supporting structures used primarily in connection with the generation. transmission, distribution, and conversion of electric power.
s itchgear assembly: An assembled equipment (indoor or outdoor) including, but not limited to, one or more of the following categories: switching, interrupting, control, instrumentation, metering, protective, and regulating devices; together with their supporting structures, enclosures, conductors, electrical interconnections, and accessories. Refer to Figure A in the Introduction for types of switchgear assemblies and related standards.
through current test: A term used to describe a short-circuit, short-time, or momentary test in which the current flowing through the test specimen is required to be maintained at or above specified levels for a specified duration.
tin-surfaced or equialcnt: Metallic materials having satisfactory long-term performance that operate within the limits established for tin-surfaced electrical contact parts and conducting mechanical joints.
truck-operated cell switch: See: truck-operated contact.
truck-operated cont*ct (TOC): A circuit breaker truck-operated auxiliary switch which is mounted in the compartment of a removable circuit breaker and is operated by the circuit breaker frame. Srri: truckoperated cell snitch.
sertical section: That portion of the switchgear assembly between two successive vertical delineations, and may contain one or more circuit breakers, auxiliary compartments, and associated primary conductors.
4. Normal (usual) service conditions
Standards for the design and performance of LV switchgcar arc based on usual service conditions as described below. The selection of equipment for a particular application can be based on the construction and ratings as defined in this standard provided that the following usual service conditions exist:
a) The temperature of the cooling air (ambient air temperature) surrounding the enclosure of the LV switchgear is within the limits of -30 °C and +40 °C. If ambient temperatures below -5 °C will be experienced while in service, the manufacturer should consider addition of space heating or other means to enable proper circuit breaker operation. If the circuit breaker is suitable for operation correctly in an ambient of -30 °C (instead of the IEEE Std C37.13 minimum ambient of-5 °C), no special measures should be needed.
b) The atitude of the installation does not exceed 2000 m above sea level.IEEE C37.20.1 pdf download.