NGK has been supplying various kind of hollow insulators for apparatus, such as Power Transformer, Gas Circuit Breaker, Current & Voltage Transformer and so on, up to 1000kV. These insulators are designed in accordance with customer's requireme
- NGK has developed a shed profile having longer leakage distance to improve contamination in the 1980s and has established an ultralarge 12-meter hollow insulator that will be used in 1000kV power transmission systems.
Contamination performance of station insulators is influenced by the kind and degree of contamination.
It is also largely influenced by the shed shape, especially for the application of DC systems.
Based upon accumulated laboratory test data and field experiences regarding efficiency of leakage distance of various shed shapes for AC & DC systems, NGK has established the following standard shed shapes.
Single rib shed
Double rib shed
Super deep rib shed
(This shed shape is
used mainly for DC use)
DC fog withstand voltage characteristics of station insulators with various shed shapes
Test & Standard
NGK hollow insulators for apparatus can meet the requirements and tests specified in the following standards.
IEC Standards and Technical Report
|60060-1||High-voltage test techniques Part1: General definitions and test requirements|
|60233||Tests on hollow insulators for use in electrical equipment|
|60437||Radio interference test on high-voltage insulators|
|60507||Artificial pollution tests on high-voltage insulators to be used on AC systems|
|60815||Guide for the selection of insulators in respect of polluted conditions|
|61245||Artificial pollution tests on high-voltage insulators to be used on D.C. systems|
|61264||Ceramic pressurized hollow insulators for high-voltage switchgear and controlgear|
|C29.1||Electrical Power Insulators - Test methods|
|C29.9||Wet-Process Porcelain insulators - Apparatus, Post-type|
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