Megger Baker DX, User Manual

Page: 115 / 156

Procedures for Testing with the DX Host
megger.com 105
As the voltage increases, if there is partial discharge the PD waveform will display pulse activity
(indicating that partial discharge is occurring) when the expanded view is selected as shown in
the example below. The default view shows the PD waveform fully zoomed in.
NOTE: Refer to the “Options for Displaying PD Data During Testing” segment in the “Partial Discharge
Testing–Three-phase Coil Mode” section for more information on display options for the PD and surge
waveforms.
If these pulses are occurring and not meeting the threshold criteria, you might need to adjust the PD
threshold and PD # events values in the
User Settings screen to appropriately indicate PD.
When PD activity exceeds the threshold value, a PD pulse occurs, the PDIV level is reached, and
the surge voltage value is recorded as PDIV.
A red PD indicator also begins to flash just left of the X-axis.
As you continue to increase the voltage, the activity will become more pronounced and more
frequent. At the point where more than 50 percent of the surge pulses have a PD pulse, the
software records the current surge voltage level as RPDIV.
Figure 117. Acquired inception voltages (PDIV and RPDIV); single-coil mode testing.
Results shown in expanded view.
8.
To acquire the extinction voltages, hold down the PTT button and use the Voltage
Output Control knob to ramp down the voltage slowly and evenly.
9.
Touch the
Slow Ramp Rate
icon to ramp down at a slower rate if desired.