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Megger Baker ADX User Guide
51
Test Configuration
Table 5: Surge Tests section field descriptions.
Field Description
Surge Test Slide right = test enabled.
Enable Leads Check each box to enable Surge testing on the associated test leads.
Voltage Ramp Rate [V/pulse] Defines the increments in volts per pulse that the tester will ramp to the target voltage.
Target Voltage [V] Target voltage level; max voltage for test. Commonly, 2 x nominal + 1000.
Refer to “Appendix D — Recommended Test Voltages” to determine the proper voltage
level for your Asset.
Target Pulse Count The number of pulses applied to the winding after the defined test voltage is reached;
number of pulses applied to complete the test. A value in the 10–15 pulses range is
common.
PD Ramp Down Voltage [V] During PD testing, the software tests for inception voltages during ramp up and
extinction voltages during ramp down. The ramp down voltage is the level at which
PD testing can stop. Set it at a level below which extinction voltages will not likely be
detected.
Note that setting the ramp down voltage too low could result in an increase in PPEAR
near the end of the test. This increase could create a false trip. The software does not
allow a value below 250 volts.
Zero Start Override Checking this box disables the zero start feature (voltage output begins at zero volts) and
allows the tester to apply full output voltage to the unit under test. The feature is used in
situations where you want to apply a higher voltage to a unit under test without ramping
up. For example, you might test an initial single coil, ramping up to the target voltage,
then select ZS Override and apply the same voltage level to subsequent identical coils.
Line-to-line EAR Limit Checking this box, only one limit is set for all three leads. Commonly used when testing
stators that have very low line-to-line EAR by design.
Individual Line-to-Line EAR Limits Check this box when you want to set individual limits for each phase-to-phase
comparison.
1-2 EAR Limit [%] EAR limit for line 1 to line 2; comparison between line 1 and line 2.
Sets the maximum Line-to-Line Error Area Ratio (EAR) allowed between the different
leads. This is often set to 10%; however, some customers have found settings as low as
4% to be useful.
2-3 EAR Limit [%] EAR limit for line 2 to line 3; comparison between line 2 and line 3.
3-1 EAR Limit [%] EAR limit for line 3 to line 1; comparison between line 3 and line 1.
PP EAR
+
Limit Checking this box turns on the Pulse-to-pulse EAR limit. This limit should always be
turned on because it provides instantaneous protection for insulation during the surge
test.
PP Limit [%] Use this field to set the maximum Pulse-to-Pulse Error Area Ratio percentage allowed for
the test.
Coil Reference Limit [%] When set, enables pass/fail criteria when comparing the surge waveforms from the test
to a previously stored reference waveform.
PD Enabled Checking this box enables partial discharge testing. PD test elements appear in the Surge
test screen.
PD Threshold [mV] Defines the amplitude at which a high-frequency transient (PD Event) is counted towards
the PD Event Limit.
PD Event Limit Defines the cumulative number of PD Events during each surge pulse required to
constitute a PD surge pulse. When the number of PD Events exceeds this limit, a PD
surge pulse is detected.
Reference Waveform 1 Select reference waveform 1. Stored reference waveform for phase A; line 1–2.
Reference Waveform 2 Select reference waveform 2. Stored reference waveform for phase B; line 2–3.
Reference Waveform 3 Select reference waveform 3. Stored reference waveform for phase C.; line 3–1.
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