Screening isolation test

Referenz WSK Elektronik

Screening Isolationsprüfung

Endurance insulation/ dielectric strength test with environmental simulation (condensation water test).

Our electrical component life testing facility tests insulation resistance and insulation and dielectric strength over life under elevated stress conditions. A streamlined life test takes place in the climate simulation/environmental simulation screening cabinet.

The test specimen

DUTs include stator windings of electric motors, other enameled wire coils, switches and pushbutton elements, sensors and actuators with insulating circuits, or devices that fall under the protective grounding class. The test can be applied to all continuous running applications that require insulation testing/measurement.

The test equipment

The equipment consists of a climatic/environmental simulation cabinet and our intelligent insulation test equipment. It depends on the application whether it is a simulation cabinet with humidity or only a temperature cabinet. In the test cabinet, the DUTs are installed in a suitable fixture and electrically connected to the test/measurement equipment.

The insulation test equipment consists of a measuring computer and a combined high voltage unit. AC voltage and also DC voltage tests under high voltage (AC/DC-HV) can be performed. The test voltages are adjustable up to 1000 V. Higher voltages are also possible as an option.

The test

In the presented application, a multi-stage test of up to 90 DUTs is provided:

  • Immediately after installation of the DUTs, the insulation resistance "start value" of the DUTs is measured. DC test with selectable voltage up to 1000 V.
  • Then the continuous breakdown test is carried out over several days, weeks to months with climate simulation. This test is performed here with AC voltage such as 230/440 up to 1000 V. The voltage can be set in 1 volt steps. Special conditions can be programmed with humidity in lower voltage or without humidity in higher voltage. The breakdown current is measured and monitored during the entire test period. Defective specimens, i.e. those that have broken through, are automatically removed from the test and the time of breakdown and breakdown current are recorded.
  • At the end of the endurance test, a final measurement of the insulation resistance is performed on the parts that have not yet experienced a breakdown during the endurance test ("good parts"). Together with the initial value, this provides a statement of the insulation behavior over the service life.
  • Finally, before the test specimens are removed, the breakdown voltage can be measured. For this purpose, the test voltage is continuously increased and the voltage at which the DUT breaks down is measured.
  • In this application, the DUTs are divided into three independent groups of 30 DUTs each. An independent test voltage can be set for each group.
  • A log file is kept of the test events, the measured values and times (when did a breakdown occur, etc.) are displayed in a table and saved in a measurement file.
  • The test is very clear. Despite the large number of test items, it is possible to see at a glance what the current test status is.
  • All relevant data is saved for later process analysis.

Your application

The above mentioned voltages, currents, number of DUTs, tests are examples from a number of our applications and can be customized to your needs. For example, it is conceivable to include a DUT actuation with function test or also mechanical stress such as buckling of connecting cables in the endurance test. There are no limits to your wishes here. It is best to send us your specifications or talk to our application engineer!