Composite post insulators are used in outdoor substations or apparatus. They provide insulation and supporting. The both end fittings can be the same or different, they are decided by the connection of other equipments.
According to different application area, the mechnical load can be compression strength, cantilever strength, tensile and torsional strength. Specified mechnical load can be got by failing load test. When the insulator get its SML, the post insulator doesn’t break, but have a deflection. The insulator should meet the deflection requirement as per standard. MDCL is also a important parameter for composite post insulators, normally it is as much as 50% of the SCL.
Important parameter: (if you want to enquire, the following must be provided)
When the composite post insulators are applied in ultra high voltage area, and require the height above 1300m, normally the insulators will be made into several units and stack them together to get the required electrical performance.