T775J ELECTRONIC REMOTE TEMPERATURE CONTROLLER
63-2248—4
11
쐎Press Enter to enter the displayed value into memory.
쐅Press Select four times to return to stage 1 parameters.
Scroll through the programming loop a second time to
confirm that the appropriate values have been entered
into memory.
NOTE: The T775J has three options for displaying the
sensed temperatures:
1. Sensor A only.
2. Sensor B only.
3. Alternating between Sensor A and Sensor B.
쐈Press Select after viewing the switching differential for
the final stage to display Sensor A temperature only.
쐉Press Select again to display Sensor B temperature
only.
씈Press Select again to alternate the display between
Sensor A temperature and Sensor B temperature at
approximately five second intervals.
씉Before replacing the cover on the T775J, check to see
that the control values have been recorded on the label
on the back of the cover.
NOTE: The control values programmed into memory will not
be lost because of a power failure.
Calibration Procedure for 0 to 18 Vdc Output T775J
NOTE: The 0-18 Vdc Output T775J models have field
selectable starting voltages and spans and will
require calibration. The Series 90 and 4-20 mA
output devices require no calibration.
쐃Disconnect power to the device.
쐇Remove the device cover and disconnect the load from
the plus and minus outputs. Connect a dc voltmeter to
the plus and minus modulating outputs of the T775J
(see Fig. 12).
쐋Loosen the screw in the upper right corner of the T775J
approximately six turns with a screwdriver (see
Fig. 12).
쐏Rotate the display printed wiring board outward from
the device until it is approximately perpendicular to the
enclosure (see Fig. 12).
쐄The T775 is factory set to a span of 8 Vdc. To select a
different span (3 Vdc, 14 Vdc, or 17 Vdc), change the
switch positions on the voltage selection switch by
opening the switch for 8 Vdc and closing the switch for
the chosen span (see Fig. 12).
쐂Apply power to the device.
쐆Press Select until Sensor A temperature is displayed.
쐊Record the sensed temperature.
쐎Determine the operating mode for stage 1 (Heat or
Cool). Choose the appropriate example to follow.
Calculate the setpoints to be used for calibrating the
device in column B, following the example in column A.
Calibration Setpoint for Cooling Mode (Fig. 13)
Setpoint for calibrating the lower voltage level (closed
position): AB
Sensed Temperature 78°
Add 3° F or C to above: +3°
Calibration Setpoint: 81°
Calibration Setpoint for Heating Mode:
AB
Sensed Temperature: 78°
Subtract 3° F or C from above: -3°
Calibration Setpoint 75°
Calibrate the Lower Voltage Level (Closed Position).
쐃Read displayed temperature of sensor that is controlling
stage 1.
쐇Press Select until the setpoint for stage 1 is displayed.
쐋If stage 1 is in the HEAT mode, press Set (down arrow)
until the setpoint is at least three degrees below the
temperature in step 1.
쐏If stage 1 is in the COOL mode, press Set (up arrow)
until the setpoint is at least three degrees above the
temperature in step 1.
쐄Press Enter to enter this value into memory.
쐂Press Select once so that the throttling range is
displayed.
쐆Press Set (up arrow) or Set (down arrow) until the
throttling range is two degrees.
쐊Press Enter to enter this value into memory.
쐎Connect voltmeter as shown in Fig. 8.
쐅Press Select until Sensor A is displayed (if the sensed
temperature has drifted from step 1, you may need to
repeat steps 2 through 8).
쐈Turn the zeroing voltage potentiometer with a
screwdriver until the desired lower voltage (i.e., 2V, 6V,
etc) is displayed on the voltmeter.
쐉Confirm upper voltage level:
•Record the sensed temperature for sensor
controlling stage 1.
•Press Select until stage 1 setpoint is displayed.
•If stage 1 is in the HEAT mode, press Set (up
arrow) until setpoint is at least three degrees
above the sensed temperature.
•If stage 1 is in the COOL mode, press Set (down
arrow) until setpoint is at least three degrees
below the sensed temperature.
•Press Enter to enter this value into memory.
•Record the (desired) upper voltage level.
•If the value is not correct, make sure the correct
span switch is depressed and the stage is in the
correct mode of operation (HEAT or COOL).
Verify which sensor is controlling stage 1.
씈Rotate the display printed wiring board back into the
device and tighten the screw in the upper right corner.
씉Disconnect the voltmeter from the modulating outputs
and connect the load to the plus and minus terminals of
the modulating terminal block.
씊Return to Programming Stage Control Values to enter
the desired stage control values.