Procedures for Testing with the DX Host
112 Baker DX 71-030 User Guide EN V10
www.megger.com
Span Test Procedures
The Baker DX as a standalone unit can perform DC FC (field coil) and span (armature winding, or
arm span) testing. The armature span test is typically used as a substitute when the low-
impedance functionality of a Baker ZTX tester or accessory is not available (includes Baker AT-101
ZTX, Baker PP85 power pack, or Baker DX-15A). If a ZTX-capable option is available, bar-to-bar
testing is recommended over span testing.
Span testing can be done with any Baker DX tester using Surge test mode. The ATF-4000 test
fixture is used during this test procedure. Refer to the instructions provided with the fixture for
connection, use, and maintenance instructions. The fixtures probe points are used to contact
commutator bars that are 5–10 bars apart. The number of bars between the probes is called the
span
.
To test the armature windings with the span test, the probes are placed on the commutator, the
test button or foot switch on the Surge tester is pressed and a Surge test voltage is applied
between the probes.
NOTE: A second operator should be available to start the process and obtain the reference waveform.
When a satisfactory reference is saved and the zero-start override has been set, a single operator can
complete the process.
It is necessary to have the zero-start circuitry disabled so that the test voltage will go straight to
the test voltage without the operator having to manually ramp up the voltage.
When span testing, every bar is tested around the circumference of the commutator. For
example, if a span of 7 bars is being used, bar 1 and bar 7 are tested. The probes are next
moved to bar 2 and bar 8 and the test repeated. This pattern continues until all bars around the
commutator have been tested.
1.
Temporarily label the bars on the armature to be tested with the bar numbers. Labeling
every 5th or 10th bar is all that is necessary.
Figure 124. Armature labeling for span testing.
2.
Ensure the footswitch is attached to the Baker DX.
3.
The ATF-4000 fixture will be used to conduct the tests.
Summary of Contents for Baker DX
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Page 10: ...Table of Contents viii Baker DX 71 030 User Guide EN V10 www megger com...
Page 28: ...Baker DX Instrument Overview 18 Baker DX 71 030 User Guide EN V10 www megger com...
Page 38: ...Baker DX User Interface Overview 28 Baker DX 71 030 User Guide EN V10 www megger com...
Page 58: ...Setting up the Baker DX Tester 48 Baker DX 71 030 User Guide EN V10 www megger com...
Page 149: ...megger com 139 RIC Templates Figure 141 RIC template 1...
Page 150: ...RIC templates 140 Baker DX 71 030 User Guide EN V10 www megger com Figure 142 RIC template 2...
Page 155: ...Index megger com 145...
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