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Low-impedance Armature or Coil Testing Using the Baker PPX30A
Some coils or armature windings have very low impedance and cannot be tested with just the DX host. Baker ZTX
functionality is required to test these coils. DC series fields, pole face windings, and interpoles are common examples
of low-impedance circuits that require the ZTX functionality for proper evaluation. When combined with a PPX30A
power pack (built-in ZTX functionality), the Baker DX accommodates testing of low-impedance coils and armatures.
Low-impedance Armature or Coil Test Procedures for PPX30A
1. Ensure that the test probes or fixture have been properly connected to the power pack, then power up the Baker
DX and the power pack.
2. Ensure that the
Test Select
switch is set to Leads Ground (
Ground icon
) and the
Function Selector
switch is
set to Armature (
armature icon
). The power packs’ high-voltage test leads are not used during this test; safely
set them aside.
CAUTION: To avoid damaging the unit under test or substantially reducing the switching element’s useful life, do not
change the
Function Selector switch out of the Armature position during the performance of any test.
3. Turn the PPX30A Zero-start Override key switch to the horizontal position to enable zero-start override.
WARNING: When the zero-start override feature is enabled, target test voltage levels will be instantly
applied to the test leads when a test begins. Ensure that no one contacts the tester leads to avoid injury
during testing.
Fig 57: PPX30A Zero-start override key switch.
Item Description
1 Zero-start override. This key switch overrides the Zero Start function and allows the unit to
immediately apply the full target voltage level to the test leads. With the key in the vertical
position, testing starts at zero volts and must be ramped up to the target voltage level.
2 In the horizontal key position, zero-start override is enabled. When the zero-start override
feature is enabled, target test voltage levels will be instantly applied to the test leads when a
test begins.
Using Power Packs with Baker DX Testers
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