Allen-Bradley PowerFlex 20P, Hardware Service Manual

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Rockwell Automation Publication 20P-TG001C-EN-P - February 2018 35
Component Test Procedures Chapter 2
8. With the digital multimeter set to “diode test”, measure each connection
point on the pulse transformer board that is listed in these tables. If any
of the actual measurements are out of tolerance, replace the pulse
transformer board.
Check the Field SCR/Dual Diode Module (Drives Only)
The field supply consists of a dual pack SCR/Dual Diode module that is
arranged in a single–phase full wave rectifier configuration. Malfunction of
either of these components can cause various responses including field and
velocity-related faults, or blown fuses. The following procedures can be used if
field bridge malfunctions are suspected.
1. Read the General Safety Precautions on page 10 .
2. Remove power from the drive (see page 46 ).
3. Verify that contactor power (if used) is removed.
4. Verify that power to an external field supply (if used) is removed.
5. Check the anode to cathode junction of the field SCR/dual diode
module. With the digital multimeter set to “diode test”, measure the
resistance across the modules. See
Table 10 on page 36 and Figure 10 on
page 36 .
If a low resistance is detected, replace the modules. See Field SCR/Dual
Diode Module and Field Circuit Board Replacement on page
89 .
If a measurement results in an “infinity” reading, check the fuses at FV1
and FU1 on the bottom of the drive to determine if they are open. See
Figure 10 on page 36 .
Table 8 - Armature Pulse Transformer Primary Measurements for Regenerative and Non-
regenerative Drives
For SCR (+) Meter Lead (-) Meter Lead Meter Reading Connector XY Pinout
1/01 XY-8 XY-1 0.41 Ω
4/04 XY-8 XY-4
2/02 XY-8 XY-2
5/05 XY-8 XY-5
3/03 XY-8 XY-3
6/06 XY-8 XY-6
Table 9 - Armature Pulse Transformer Primary Measurements for Regenerative Drives
For SCR (+) Meter Lead (-) Meter Lead Meter Reading Connector XY Pinout
1 XY-7 XY-1 0.41 Ω
4 XY-7 XY-4
2 XY-7 XY-2
5 XY-7 XY-5
3 XY-7 XY-3
6 XY-7 XY-6
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