3.4.41 ACRT - AC Hi Pot Ramp (AC)
The ac high-pot Ramp test is used to check for safety isolation between windings, or between windings and the core or screens.
During the test, an ac target voltage is applied across two groups of windings with the windings in each group being shorted together. The voltage is ramped and the current is monitored throughout the ramp time; if either the test voltage cannot be maintained, or the current is too large, then a failure will be recorded.
On selecting ‘ACRT High-Pot Ramp’ from the Available Tests window, a dialogue box will be displayed:
To program the test :
- Enter the target voltage, 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 current value in the bottom section.
Note that the current is the peak value, not an rms.
- 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.