Impulse Dielectric Test
Electrical FOR: Insulation $880The impulse dielectric tests can be thought of a production line means of checking for insulation/jacket breaches in wires/cables.
In this test, a voltage is placed on the specimen and the specimen is pulled under a 'chain mail' curtain connected to ground. The test is performed at a higher voltage than the standard dielectric tests performed on wires/cables, but this is necessary given the short duration of the voltage differential across the insulation/jacket. Further, since the voltage application is so short, the electrical degradation of the insulation is negligible.Parameters that can be changed for this test:
- Voltage
- Duration of voltage exposure (pull through speed)
Procedure
- Perform a visual examination of the specimen. Record any observed defects.
- Strip the insulation/jacket from the specimen and connect the line-side of the high voltage power supply.
- Turn on the power supply and slowly increase the voltage to the specified voltage (when testing cable jackets, the specified voltage is typically less than for individual wires.
- Pull the specimen through the electrically grounded metal curtain. Record if any breaches in the insulation/jacket are detected.
- Report the voltage used, the specimen length, high voltage exposure duration, and humidity.
Covered specifications
- NEMA27500 Method 4.3.3
- MIL-STD-2223 Method 3002
- AS4373 Method 503
- AS4373 Method 505
- ASTM D3032 Method 13