ANSI NEMA C29.8-2017 pdf free download – Wet Process Porcelain Insulators — Apparatus, Cap and Pin Type.
8.1 General Tests described in 8.2 shall be required only on insulators of new designs. Tests described in 8.3 shall be required on each lot of insulators. Tests described in 8.4 shall be made on each insulator. Electrical tests described in 8.2 shall be conducted on complete insulator assemblies. 8.2 Design Tests
8.2.1 Low-Frequency Wet Withstand Three insulators shall be selected at random and tested in accordance with Clause 4.5 of ANSI/NEMA C29.1, Low-Frequency Wet Withstand Voltage Tests. Failure of more than one insulator to meet the rated wet withstand value given in Table 1 shall constitute failure to meet the requirements of this standard. If only one insulator fails to meet the rated wet withstand value given in Table 1, the retest procedure of Clause 4.3 shall apply.
8.2.2 Critical Impulse Flashover, Positive Three insulators shall be selected at random for the critical impulse flashover test, positive, and tested in accordance with Clause 4.7 of ANSI/NEMA C29.1, Impulse Flashover Voltage Tests. Failure of the average critical impulse flashover value of these three insulators to equal or exceed 92 percent of the rated critical impulse flashover value given in Table 1 or failure of any individual value to equal or exceed 85 percent of that value shall constitute failure to meet the initial test requirements, and the retest procedure of Clause 4.3 shall apply.
8.2.3 Impulse Withstand Three insulators shall be selected at random and tested in accordance with Clause 4.8 of ANSI/NEMA C29.1, Impulse Withstand Voltage Tests. Failure of more than one insulator to meet the rated impulse withstand value given in Table 1 shall constitute failure to meet the requirements of this standard. If only one insulator fails to meet the rated impulse withstand value given in Table 1, the retest procedure of Clause 4.3 shall apply.
8.2.4 Radio-Influence Voltage (RIV) Three insulators shall be selected at random and tested in accordance with Clause 4.9 of ANSI/NEMA C29.1, Radio-Influence Voltage Tests. If one or more of these insulators fails to meet the requirements given in Table 1, the retest procedure of Clause 4.3 shall apply.
8.2.5 Compression Strength Three insulators shall be selected at random and tested in accordance with Clause 5.1.4.4 of ANSI/NEMA C29.1, Compression Strength. Failure of more than one insulator to meet the rated compression strength value given in Table 1 shall constitute failure to meet the requirements of this standard. If only one insulator fails to meet the compression strength value given in Table 1, the retest procedure of Clause 4.3 shall apply.
8.2.6 Thermal Shock Three insulators shall be selected at random and tested for 10 complete cycles in accordance with Clause 5.5 of ANSI/NEMA C29.1, Thermal Test. The temperature of the hot water bath shall be approximately 150°F (66°C), and the temperature of the cold water bath shall be approximately 39°F (4°C). If one insulator fails, three additional insulators shall be selected at random and tested. Failure of more than one insulator from the first sample or from the first and second samples combined shall constitute failure to meet the requirements of this standard.
8.3 Quality Conformance Tests
The distribution of samples between Clause 8.3.4, Clause 8.3.5, Clause 8.3.6, and Clause 8.3.7 shall be subject to agreement with the purchaser.ANSI NEMA C29.8 pdf download.