Danfoss Turbocor TT Series, Service Manual, Page: 218 / 294

4.26.3.2 Serial Driver Output Voltage Verification
1. Remove the Service Side Cover. Refer to Section 4.1.3.1 Service Side Cover Removal and Installation on
page 54.
2. Isolate compressor power and wait for the Backplane LEDs to go out.
3. Wait a minimum of one (1) minute.
4. Reapply compressor power.
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The Alarm LED will illuminate green and the Cool-H, Cool-L and Run LEDs will illuminate amber, all
for about five (5) seconds. The Alarm LED will then switch to red and the others will turn off.
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After the compressor completes start-up check, the Alarm LED will change to green (provided no
alarm is present) and the IGV LEDs will flicker until the IGV is reset. Additionally, if an external
expansion valve is connected to the I/O board, the LEDs on the I/O board will flicker as the external
expansion valve is reset.
5. Install the Service Side Cover. Refer to Section 4.1.3.1 Service Side Cover Removal and Installation on
page 54.
4.26.4 Serial Driver Removal and Installation
4.26.4.1 Serial Driver Removal
1. Isolate compressor power.
2. Remove the Service Side Cover. Refer to Section 4.1.3.1 Service Side Cover Removal and Installation on
page 54.
3. Wait for the LEDs on the Backplane to turn off.
4. Carefully disconnect the Serial Driver from the Backplane and slide it slowly away from the compressor.
Refer to Figure 4-244 Serial Driver Removal.
Figure 4-244 Serial Driver Removal
4.26.4.2 Serial Driver Installation
1. Carefully align the Serial Driver on top of the BMCC. Refer to Figure 4-245 Insertion Guides.
Figure 4-245 Insertion Guides
Page 218 of 294 - M-SV-001-EN Rev. H 1/23/2023