Technical specifications for line-to-line connectors typically define the product's operating environmental temperature and humidity. The distinction between test environment conditions and operating environment conditions is significant. The technical specifications stipulate that the product can operate under the aforementioned temperature and humidity conditions, but this does not imply that the insulation resistance should always meet the assessment criteria under normal atmospheric pressure during testing. The assessment should be based on the criteria for high-temperature and thermal environment tests as specified by the technical conditions, rather than the criteria under normal atmospheric pressure.
Recommend that during product delivery and acceptance testing, the insulation resistance should be controlled at an appropriate level above the specified value, maintaining a certain margin. Do not classify products that just meet the specified value under dry conditions as qualified for shipment, as this may lead to inconsistencies in test results due to differing climate and environmental conditions between suppliers and buyers. To clarify the requirements for test environment temperature and humidity, some testing methods now not only specify the environmental temperature and humidity for testing but also the requirements for temperature and humidity during dispute arbitration.
Due to the inherent capacitance between the measured connectors, the power supply must first charge the capacitance during the initial measurement phase. As a result, it is normal for the resistance value indicated on the insulation resistance tester to gradually increase. Many connector testing methods explicitly state that the readings on the insulation resistance tester must be taken after one minute of voltage application.
Connector technical specifications stipulate that the insulation resistance between all contact pieces and between each contact piece and the housing should meet the specified values. It also requires that the duration of applied voltage must exceed one minute. The insulation resistance is tested by applying test voltage in parallel between the contact pieces, rows, and all contact points to the housing. This method of applying voltage in parallel using a testing fixture is more stringent than applying voltage between individual contact points. Therefore, if the insulation resistance is found to be不合格 during testing with the fixture, it is permissible to retest by directly applying voltage between single points using a test probe without the fixture.
Of course, even when using inspection gear, it is essential to ensure the gear is qualified before inspection. The gear must be clean and dry, with its inherent insulation resistance meeting the required standards and having ample margin.
