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T775P SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLER
–
DIGITAL INPUT
+
NO
DIGITAL OUTPUT
C
ALARM
NC
NC
C
NO
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.
62-0256—11
IMPORTANT
See "1.2.2.2. CALIBRATE (the sensor)" on page 14 for
the instructions to enter the calibration value.
Table 3. Temperature Sensor Calibration for Resis-
AWG
Rating
14
16
18
20
22
M24392A
AWG
Rating
14
16
18
20
22
a
This is the distance from the controller to the sensor
(already accounts for round trip distance).
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).
RESISTANCE (OHMS)
1489
1403
1317
1231
1145
1059
973
887
801
-40
-20
-40
-30
POSITIVE TEMPERATURE COEFFICIENT (PTC) OF 2.1 OHMS PER °F
1
Fig. 13. Sensor Resistance vs. Temperature.
8
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.
tance Loss due to Wire Length.
Temperature Offset in
mΩ/ft
200 ft
2.5
0.46
4.0
0.72
6.4
1.16
10.2
1.86
16.1
2.92
Temperature Offset in
mΩ/m
100 m
8.3
0.44
13.2
0.68
21.0
1.10
33.5
1.74
52.8
2.74
1097 ± 0.08 OHMS
AT 77°F (25°C)
1
0
20
40
60
80
100 120 140 160 180 200 220
-20 -10
0
10
20
30
40
50
TEMPERATURE (DEGREES)
a
°F (Foot)
500 ft
1,000 ft
1.14
2.28
1.82
3.64
2.90
5.82
4.64
9.28
7.32
14.64
a
°C (Meter)
200 m
300 m
0.86
1.30
1.38
2.06
2.18
3.28
3.48
5.22
5.48
8.22
250
°F
60
70
80
90 100
110
120
°C
M24304
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