2
Pillow Block Assemblies with Embedded Thermocouple and Transmitter
A. Connection to a PLC:
– The transmitter output can be connected directly to an
analog input card with internal loop power supply.
– Typical cards that can be used from Allen Bradley are
1771-NBSC and 1771-NB4S.
B. If a PLC is not available, the panel mounted temperature
indicator available from DODGE can be used to power
the transmitter and display the temperature. The indicator
model is CT1010, Part No. 055221. The indicator has two
settable alarm relays for warning and shut down. The
connections are shown in the instruction manual supplied
with the indicator.
I. Pillow block assemblies equipped with embedded
thermocouple, transmitter and data acquisition system is
shown in Figure 3.
II. Connection of pillow block with loop driver or data
acquisition system is shown in Figure 4 and Figure 5.
1. Take the top cover (1) off from the housing (2) by
removing the four screws.
2. Install a
1
/
2
" liquid tight electrical fitting (3) on the
cover (1) using the hole on the side.
3. Use a flex conduit (4) between the cover and the loop
driver or your data acquisition system. Voltage supply
required is 8.5 volts to 35 volts DC with no load.
4. Install the signal wires (two twisted copper wires) (5)
inside the flex conduit.
5. Connect the ends of the two wires to the transmitter
(6) terminals 1 and 2 and secure the screws.
6. Loop resistance: The maximum allowable resistance
of the signal carrying load, including extension wires
and load resistance, is given by this formula:
R approximately = (V supply – 8.5V)
.02 amps
Example:
If supply voltage is 24 VDC, the loop resistance must
be less than 775 ohm (wires plus R1). Use 80% of the
calculated value to protect against drop in voltage.
7. Replace the cover and tighten the four (4) screws.
8. Connect the other ends of the two wires (5) to your
loop driver/power supply or your data acquisition
system with built-in power supply.
9. Your system should now be able to read the
temperature between 0 and 250ºF.
10. The output of the transmitter is 4–20 mA (milliamps).