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Rockwell Automation Publication 20P-TG001C-EN-P - February 2018
Chapter 2
Component Test Procedures
Figure 9 - SCR Connection Pinouts for Non-regenerative Drives
Check the Pulse Transformer Board
The armature-pulse transformer circuit board contains an isolated gate firing
circuit and also provides dv/dt protection for the armature SCR modules. One
of the following can indicate a malfunction of these modules:
• An Overcurrent fault (F13)
• Blown or tripped incoming protection devices
• Erratic motor operation
If a malfunction in this circuitry is suspected, follow theses steps.
1. Read the General Safety Precautions on page
2. Remove power from the drive (see page
3. Remove the protective covers from the drive (see page
4. Remove the control EMI shield and control board (see page
5. Remove the slotted air flow plate from the top of the drive.
Table 5 - SCR Gate to Cathode Junction Measurements for Non-regenerative Drives
On SCR Module
SCR
Measure from
To
Nominal Meter Reading
01
01
Pin 6
Pin 7
5…20 Ω
(1)
(1) The actual reading varies depending upon the SCR manufacturer. Verify that the actual measured value is consistent for all SCRs.
04
Pin 5
Pin 4
02
02
Pin 6
Pin 7
05
Pin 5
Pin 4
03
03
Pin 6
Pin 7
06
Pin 5
Pin 4
12
3
12
3
12
3
6 7
4 5
SCR Module 01
SCR Module 02
SCR Module 03
Gate Lead
Pinouts
6 7
4 5
6 7
4 5