3.4.43 ACVB - AC Voltage Break Down
This test may be used to check the action of devices such as metal oxide varistors (MOV) that are used to protect transformer windings from transient over-voltages that may be present on the ac supply system.
During the test, an ac voltage is ramped up across the protection device (MOV) under test and the current is monitored. When the desired current flows, the test stops and the measured result is the break-down voltage. If the voltage is within the desired limits, the test is a PASS. If the voltage is outside the desired limits, or if no breakdown is detected when the maximum voltage is reached, the test is a FAIL.
On selecting ‘AC Voltage Breakdown’ test from the Available Tests window, a dialogue box will be displayed:
To program the test:
- Enter the target current, the test frequency, and the ramp-up time.
- Enter the terminal names for the High and Low Terminals.
Click with the mouse to select a terminal from the Available list; then click the 'Add >' button to transfer it to the Used list.
(To correct a mistake, click with the mouse to select a terminal from the Used list; then click the ' < Remove' button to transfer it back to the Available list.)
- Enter the maximum voltage value in the bottom section.
- Select the user offset enabled, if required and enter the voltage value.
- Select OK. The test specification will then be displayed in the program window.