It dosent matter WHAT level he is hipotting to. The ICEA, and both IEEE 400 and IEEE 576 do not recommend DC hipotting service aged cables.
In addition the IEEE 400 states “even massive insulation defects cannot be detected with DC at the recommended voltage levels”. If massive insulation defects cannot be found at recommended levels what do you expect to find at a "Fairly low" level?
Also the ICEA allows for reduced voltage DC testing for the first 5 years and no DC testing after 5 years and states that DC testing of service aged cables can lead to early failures.
