Nautel NX50, Troubleshooting Manual, Page: 89 / 205

NX50 Troubleshooting Manual Responding to alarms
Issue 6.0 2019-04-01 Page 1-79
2. If you are troubleshooting a rectifier fan alarm see " “Rectifier Fan Inspection/
Replacement” on page 1-80 , (if not, proceed to Step 3 ).
3. Disconnect all wiring attached to the SCR rectifier assembly’s A (LINE 1), B (LINE 2),
C (LINE 3), DC (+), DC (-), TB1, TB2 and TB3 terminals, taking note of the wiring
labels.
4. Remove and save (6) sets of M5 mounting hardware that support the SCR rectifier
assembly.
5. Carefully lift and remove the SCR rectifier assembly from the transmitter.
6. Obtain a replacement SCR rectifier assembly (Nautel Part # 207-7055-05).
7. Reverse Step 3 through Step 5 to reinstall the new or repaired SCR rectifier assembly.
Ensure all connections are tight, noting the following connections have special torque
values:
• LINE 1, LINE 2 and LINE 3 require 7.6 N-m (67 in-lbs) of torque.
• DC (+) and DC (-) require 6.8 N-m (60 in-lbs) of torque.
• TB1, TB2 and TB3 require 0.45 N-m (4 in-lbs) of torque.
For wiring termination assistance with connections to the SCR rectifier assembly
(A48), check the wiring list in Section 4, “Wiring/connector lists” on page 4-1 .
8. Close and lock the rear door, turn AC back on and ensure alarm is cleared.