The companies have suffered from low operational reliability of porcelain insulators mounted at substations located in the regions with significant temperature fluctuations.
The field personnel was prescribed previously to conduct certain scope of highly cost-plus administrative and technical measures able to provide fault-free operation of insulators, in particular, thorough visual inspections, trouble-shooting examinations of mechanical condition of rod post insulators along with restoring repairs of the insulators.
In 1998 power engineers have drastically increased technical requirements to the mentioned type of products. Starting from January 1st, 2004 the new corresponding Russian state standard for the technical requirements was introduced.
Power engineers were granted with an alternative – polymer post insulator.
One shall note that taking into account existence of other similar conditions, application of polymer post insulators is more preferable in following cases in comparison with porcelain insulators:
- In frigid climate regions where drastic seasonal and daily temperature differentials are registered;
- In regions with potentially high seismic activity;
- In regions characterized by high-rate air contamination;
- In disconnectors with manual-operated switch blades of the main current-carrying contour;
- In areas with high probability of vandal acts’ occurence.