Thermo Scientific 61-12N-64P, Operating And Service Manual

Page: 11 / 19

Ramsey Model 61-12N Speed Sensor REC 4374B Page 11
Electrical Wiring
Use the following procedures to make electrical connections:
1.
Remove the terminal strip cover (Figure 1) and the dust plug from the threaded conduit aperture in
the speed sensor housing.
2. Install 1/2 inch flexible conduit to the speed sensor housing.
3. For 61-12N-64P use Belden 8772 or equivalent, 3 conductor, 20 AWG, shielded. Maximum distance is
500 feet (150 meters). For distances of 500 to 3000 feet (150-915 meters), use Belden #1036A or
equivalent, 3 conductor, 18 AWG shielded. Cable temperature rating must exceed minimum and
maximum ambient conditions.
4. Do not put speed sensor cables in the same conduit as power wiring.
5.
Connect one wire to each of terminals 15, 16, and 17 as shown in Figure 6. Replace the terminal strip
cover.
CAUTION: The three wires connecting the speed sensor to the integrator/totalizer must be shielded.
Refer to system wiring diagram for proper shield termination.
6. Do not terminate cable shield at speed sensor. Follow system field wiring diagrams for termination at
control instrument only.

Refer to drawing 07392BE041 at the end of this manual for Class I hazardous location installations.

Refer to drawing 07392BE042 at the end of this manual for Class II or III hazardous location
installations.

Refer to drawing 07392BE043 at the end of this manual for non-hazardous area location
installations.
Figure 6. Field Wiring
SPEED SENSOR
61-12N-64P