Copyright © VibroSystM Inc., 2010
14
PCS-200ESB Universal Proximity Sensor_Installation_Rev. 1
O
2.2.3.1
Sensor installation on an insulated bearing
When a sensor is installed on an insulated bearing, special care must be taken while mounting the bracket to
preserve the integrity of insulation. Insulation must be added between sensor housing and insulated bearing
surface, but low impedance at high frequency must still be achieved. The most widely recommended
mounting method consists in placing a mica sheet (1.6 mm
[0.063”]
thick or less) between mounting bracket
and bearing, and using either non-metallic bolts, or metallic bolts insulated from the bearing by phenolic
sleeves and washers .
Figure 10 : Installation on an insulated bearing
Verification:
1. Once the bracket is installed, test with a ohmmeter for an open circuit condition between the mounting
bracket and insulated bearing.
2. Place a temporary cable between the sensor casing and insulated bearing to create a short-circuit path.
3. Complete the measuring chain by connecting the sensor to its LIN-300 Series conditioner and apply
power to the conditioner. Take a measurement of the 4-20 mA output signal .
4. Remove the temporary cable between the sensor casing and insulated bearing.
5. Take a new measurement. The results should be similar to the previous reading, within a +/- 2 mA margin.
6. If the results differ beyond the mentioned margin, the insulating sheet is probably too thick. A thinner sheet
should be used before going through the verification procedure again.
Caution
If the sensor is installed on an insulated bearing, a thin insulation sheet must be placed between
the mounting bracket and the insulated bearing. Insulated screw assembly, such as phenolic
sleeves and washers, must also be used.
Bolt
Mica sheet
