The AC Hipot test checks the insulation of a device to make sure that there is not a voltage breakdown between the electrical components and conductors in the device, and the chassis ground of the device.
A high AC voltage is applied to the connection wires of the device, and the frame of the device is grounded. The return side of the hipot unit must also be connected to ground. In some cases, it is necessary to float the return and not connect it to ground, but that will not be considered in this writeup.
The hipot can fail for having high leakage current, a ground, an ARC, or low leakage current.
To verify that the hipot test is working, do the following...
First, disable all other tests except hipot.
1. To verify that high leakage is detected, temporarily adjust the hipot maximum, either in the hipot itself, or in the software, lower than the actual, and see if it fails for high leakage.
2. To verify that a ground is detected, skip all other tests but hipot, and place a wire between the test clip and the chassis ground of the device. The test should fail for a ground. A high leakage reject is also acceptible in this exercise.
3. To verify that an ARC is detected, connect a wire to chassis ground. The other end, hold in your hand and wait. Start a hipot test, after the hipot test has started, and before it is complete, touch the other end of the wire to clip 1 of the clip block, or to a conductor on the test connector being used. The test should fail for ARC.
4. To verify that low leakage is detected, first, completely disconnect the device from the clip block, or test connector. The test should fail. Then, reconnect the device under test to the clip block, or test connector, and isolate the device from where it is connected to the chassis of the machine. If the device sits in a metal fixture, then set the device on delrin, or wood. If the device has a ground wire, disconnect and...