The standard specifications followed are IS 2544 and IEC 60168
Tests are categorised in three parts
- Routine test
- Acceptance test
- Type tests
- Routine test
- Visual examination
Bending load test at 50% of the load for 1 minute in all 4 directions
- Acceptance test
- Visual examination
- Dimensional verification
- Temperature cycle test
- Mechanical Failing load test
- Porosity test
- Galvanization test
Like in disc and Pin insulators, here too acceptance tests are carried out on sampled pieces. IS/IEC standards specify the sampling plan. The sample as per the standard for a lot of below 500 Nos of insulators is not specifically mentioned. Instead this is to be decided between the buyer and the supplier. Normally 1% of the total number of offered quantity is selected for tests
