IEEE C37.122.5-2013 pdf free

IEEE C37.122.5-2013 pdf free.IEEE Guide for Moisture Measurement and Control in SF6 Gas-Insulated Equipment.
Note that the term GIS is used throughout this guide as a simplified term, but is also meant to include other types of GIE as applicable. There are two separate and distinct issues relating to moisture within GIS:
a) Very high levels of humidity increase the possibility that water molecules will condense into the liquid phase, adversely affecting the dielectric withstand strength of GIS [B14]1 and significantly increasing the possibility of flashover. Therefore, humidity in GIS should be maintained at a level such that the humidity does not condense in the form of liquid water over the entire range of the expected operating temperatures and gas pressures.
b)The formation of corrosive and toxic decomposition by-products occurs in reactions between moisture and dissociated SF6 found in the high energy arcs during normal switching operations. Higher concentrations of humidity can result in higher concentrations of decomposition by- products [B3]. These by-products cause corrosion and may degrade insulators and other internal components within the GIS, and pose a safety hazard.
In an effort to address these two potential problems, users may periodically measure humidity in their SF6gas-insulated equipment.
The following referenced documents are indispensable for the application of this document (ie,they must be understood and used, so each referenced document is cited in text and its relationship to this document is explained)，For dated references. only the edition cited applies.
For undated references, the latest edition of the referenced document (including any amend ments or corrigenda) applies.
IEEE Std C37.122.3TM-2011, Guide for Sulphur Hexafluoride (SF6) Gas Handling for High Voltage (over 1000 Vac) Equipment.2
4.3. Definitions
For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary Online should be consulted for terms not defined in this clause. 3 absorbed moisture: Water in molecular form that permeates into a bulk solid (mainly into the insulators in a gas-insulated substations (GIS) compartment).IEEE C37.122.5 pdf free download.