Danfoss Turbocor TT Series, Service Manual, Page: 236 / 294

4.30 Bearing Sensors
4.30.1 Bearing Sensor Function
Bearing sensors feed back real-time shaft orbit information to the bearing control loop. Refer to Figure 4-252
Bearing Control Signal Flow on page 226.
4.30.2 Bearing Sensor Connection
The Bearing Sensors are connected internally to the Bearing Sensor feedthroughs located above the front and rear
bearing power feedthroughs. The bearing sensor feedthroughs are connected to the bearing sensor cables which
connect to J9 and J10 on the Backplane. Refer to Figure 4-262 Bearing Sensor Feedthroughs.
Figure 4-262 Bearing Sensor Feedthroughs
4.30.3 Bearing Sensor Verification
4.30.3.1 Bearing Sensor Resistance Verification
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. Place meter leads on bearing sensor feedthrough pins outlined in Table 4-48 Bearing Sensor Coil
Resistance on page 237. Refer to Figure 4-263 Bearing Sensor Pin Locations on page 237 for pin
locations.
NOTE
There are no connections on Pins 1 & 4 and 1 & 9 on the Rear Bearing Sensor Feedthrough.
Page 236 of 294 - M-SV-001-EN Rev. H 1/23/2023