Install Instructions

T775P SERIES 2000 CONTROLLER CHECKOUT
62-0256–03 8
Fig. 12. Wiring for Digital Input (dry contact) and
Digital Output.
CHECKOUT
Inspect all wiring connections at the controller terminals,
and verify compliance with the installation wiring
diagrams.
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or property
damage.
Disconnect power supply before beginning wiring
or making wiring connections, to prevent electrical
shock or equipment damage.
If any wiring changes are required, first be sure to remove
power from the controller before starting work. Pay
particular attention to verifying the power connection (24,
120, or 240 Vac).
After the controller is mounted and wired, apply power.
Power Loss
The date and time settings are retained for 24 hours after
a power outage. After a power loss of more than 24 hours,
the date and time settings may need to be reentered. All
other settings are stored permanently.
Temperature Sensor Calibration
As wire length increases, resistance increases and thus the
temperature reading increases. If necessary, calibrate the
sensor input by reducing the value by the amount shown in
the Table 3. For example, a wire run with 18 gauge wire of
1,000 feet, requires a calibration offset of -6.0°F.
IMPORTANT
If the calibration value in the table exceeds the
controller’s calibration limits of +/-10°F (+/-6°C),
you must use a heavier gauge wire.
For example, with a wire run of 1,000 feet you
must use 20 AWG wire or heavier to calibrate for
wire loss within the limits of the controller.
See “1.2.2.2. CALIBRATE (the sensor)” on page 14 for
the instructions to enter the calibration value.
Fig. 13 shows how sensor resistance varies with
temperature for a sensor having a positive temperature
coefficient (PTC) of 2.1 Ohms per degree F (3.85 Ohms
per degree C).
Fig. 13. Sensor Resistance vs. Temperature.
C
NO
NC
M24392A
DIGITAL OUTPUT
ALARM
NO
C
NC
DIGITAL INPUT
+
–
Table 3. Temperature Sensor Calibration for
Resistance Loss due to Wire Length.
AWG
Rating mΩ/ft
Temperature Offset in
°F (Foot)
a
a
This is the distance from the controller to the sensor
(already accounts for round trip distance).
200 ft 500 ft 1,000 ft
14 2.5 0.46 1.14 2.28
16 4.0 0.72 1.82 3.64
18 6.4 1.16 2.90 5.82
20 10.2 1.86 4.64 9.28
22 16.1 2.92 7.32 14.64
AWG
Rating mΩ/m
Temperature Offset in
°C (Meter)
a
100 m 200 m 300 m
14 8.3 0.44 0.86 1.30
16 13.2 0.68 1.38 2.06
18 21.0 1.10 2.18 3.28
20 33.5 1.74 3.48 5.22
22 52.8 2.74 5.48 8.22
M24304
TEMPERATURE (DEGREES)
RESISTANCE (OHMS)
1403
1317
1231
1145
1059
973
20 40 60 80 100 120 140 160 180 200 220
0 10 20 30 40 50 60 70 80 90 100
°F
°C
0-20-40
120
110
250
-40 -20 -10-30
1489
887
801
1097 ± 0.08 OHMS
AT 77°F (25°C)
POSITIVE TEMPERATURE COEFFICIENT (PTC) OF 2.1 OHMS PER °F
1
1