Which condition would have little effect on off-line PD testing of a MV cable?

In the context of off-line partial discharge (PD) testing of medium voltage (MV) cables, each condition has a significant impact on the results and reliability of the testing. However, the question specifically asks which condition would have little effect on PD testing outcomes.

When considering the choices provided, the aspect of "none of these" would imply that all the other conditions mentioned can indeed impact off-line PD testing in varying degrees.

Cable length can influence the test results because longer cables may have higher losses and may introduce more complexities in the analysis of PD. Similarly, electrical noise on site can interfere with the detection of PD activity by obscuring the signals being measured, leading to potential misinterpretation of the test data. Lastly, resistive shield connections at the termination play a critical role in ensuring a proper ground and connection; poor connections can lead to erroneous readings or signals that may mask actual PD activity.

Thus, while it is true that various conditions can affect the testing, recognizing that all of them are influential leads to the selection of "none of these" as being the correct choice. This reinforces the understanding that careful consideration must be given to all mentioned conditions during off-line PD testing to ensure accurate and reliable results.