2.4 Panel Mounting | - refer to Table II for hole sizes and locations. | This | |
mounting requires the PVC mounting feet and four PVC mounting blocks. |
| ||
The blocks are drilled and tapped for |
|
| |
3 . Wiring
3.1 After the enclosure is properly mounted the wires for input, output, ground and remote temperature sensing should be routed through the en-
closure hubs. | These connections should be trimmed to the proper length | ||
and connected | to the circuit board assembly. | The circuit board assembly | |
should then be placed in the enclosure and fastened to the bottom of | |||
the enclosure with the two | phillips head screws supplied. | ||
3.2 The input probe connector is a BNC jack mounted on the input circuit
board. Use only a coaxial cable that has isolation around the shield. The shield is isolated from ground and this isolation should be maintained
for proper operation. For best results, | the probe cable should not be | |
longer than 10 feet. | Long cables result in slow response because the | |
probe must charge the cable capacitance through the high probe source resistance.
3.3 The output vires are isolated from the input and ground, connections are made to the terminal strip observing polarity to the terminals marked +, - out. These wires are to be connected to a D.C. power supply through
a load resistor. The wires can be as long as necessary.
3.4 The Loop resistor can be either in the positive or negative power supply lead. The value of the loop resistor depends on the voltage required
at the monitoring location. | Calculate the required power supply voltage | |||||||
from the following equation: | Minimum power supply voltage | = 12 + | c.02 | |||||
x RL). | A convenient value for the loop resistor might be 250 ohms, re- |
| ||||||
sulting in a | 1V to 5V | output signal using this as an example: RL |
| = 250 | ||||
ohms, vo = | 1v to 5v. | Minimum supply voltage | = 12 + c.02 x | 250) = | 17V. | |||
The maximum supply voltage is 80V. |
|
|
|
| ||||
3. 5 The temperature probe | is optional. | If the probe is used, it should be |
| |||||
connected to the terminal strip connection marked with the resistor | sym- | |||||||
bol. | The probe cable should be shielded and the shield connected to |
|
| |||||
the ground terminal. |
|
|
|
|
|
| ||
3.6 Manual temperature compensation requires only a resistor at the terminal
strip connection | marked with a resistor symbol. | Refer to Table I for | |||||
the value vs. temperature. | An | 8.66K | resistor is normally supplied with | ||||
the transmitter, | this value is correct for | 25'C compensation. | The re- | ||||
sistor used should be metal film | *50 | ppm/'C | or wire wound | f | ppm/OC. | ||
