Megger TDS40, Operating Manual, Page: 18 / 71

2-18
The loss of voltage caused by twice changing the polarity (device option Basis) will now
be compensated for by recharging with the negative DC source. In contrast to this at the
device option Plus the losses of a polarity reversal are immediately compensated.
The back-up capacitor has the following tasks:
- It slows the ring-around event down to the ms range even for short cables,
- It compensates a part of the losses during the polarity reversal.