Danfoss Turbocor TT Series, Service Manual

Page: 215 / 294

Table 4-42 Backplane Test Point Values
Test Point Test Point Reference DC Voltage Range Minimum Resistance
HV+ HV- 220 to 280 250Ω
+17HV HV- 16.5 to 17.85 28Ω
+24V 0V 22 to 26 9Ω
+15V 0V 14.75 to 15.25 20Ω
-15V 0V -14.75 to -15.25 150Ω
+5V 0V 4.75 to 5.25 8Ω
9. Install any components that may have been removed while testing.
10. Install the Service Side Cover. Refer to Section 4.1.3.1 Service Side Cover Removal and Installation on
page 54.
11. Return the compressor to normal operation.
4.25.3 Backplane Removal and Installation
4.25.3.1 Backplane Removal
1. Isolate compressor power.
2. Wait for the Backplane LEDs to turn off.
3. Remove the Serial Driver. Refer to Section 4.26.4 Serial Driver Removal and Installation on page 218.
4. Remove the BMCC. Refer to Section 4.27 BMCC on page 220.
5. Remove the PWM. Refer to Section 4.28.4 PWM Removal and Installation on page 228.
6. Disconnect and remove all remaining connectors from the Backplane. Refer to Figure 4-238 Backplane
Connections on page 212.
7. Remove the Inverter Ground fastener from the top right of the Backplane to release the Inverter cable
ground ring.
8. Replace the Inverter ground fastener.
9. Remove the three (3) fasteners that secure the Backplane Frame to the housing. Do not remove the
fastener at the top left or bottom center of the Backplane so the circuit board remains in the frame.
Refer to Figure 4-242 Removing the Backplane on page 216.
M-SV-001-EN Rev. H-1/23/2023 Page 215 of 294