Megger 220070 70 kV DC Dielectric Test Set

The Megger 220070-47 high voltage DC dielectric test set provides the most dependable, portable dc high voltage sources for checking the quality of electrical power cables, motors, switchgear, insulators, transformers and capacitors. The portable set is comprised of two separate modules:

Control Module
This module allows the operator to switch-select the appropriate current output range, adjust the output level and monitor both the applied voltage and leakage current at a safe distance from the high voltage being delivered to the load under test. No voltage higher than input ac power is present in the control module.

High-Voltage Module
An air-insulated design receives its instructions from the control unit. It generates the dc high voltage that is delivered to the load under test. Although a different control module is used with each of the three models, they are all the same size and weight. Each high-voltage module is a different size and weight to accommodate the rated output voltage.

Time-varying tests such as the polarisation index test (PI test) are independent of temperature effects and save time. To perform this test, a predetermined test voltage is applied to the unit under test and readings are taken at 1 minute and 10 minutes. The resulting ratio is analysed to determine insulation quality. This type of test is especially appropriate for high-capacitance samples.

The step-voltage test is independent of temperature effects and saves time. To perform this test, the output voltage is increased in even steps at regular intervals over a fixed period of time. As long as the resistance of the unit under test increases with time, it has high-quality insulation. This type of test is only useful for high-capacitance samples.