T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS
23
63-7147—3
4 Stage with Pump Output and Reset
(continued)
Wiring
All output relays should have a common power wiring source,
which may or may not be the same as the T775 power wiring.
Fig. 27. T775P Wiring - 4 Stage with Pump Output and Reset.
Device Checkout
The T775 performance can be checked out to determine if
proper operation exists.
For example, when the outside air temperature is at 50° F
(10° C), the boiler temperature should be 180° F (22° C). See
Fig. 28. Use the alternate Home screen to check that the
effective setpoint is adjusting correctly based on the outside
air temperature (sensor B).
NOTE: The alternate Home screen does not show live
updates of the sensor temperature. They show the
temperature only at the moment the button is
pressed.
1.
From the Home screen, use the
$
button to verify
the setpoint temperature for each output.
2.
Then, press the
HOME
button to view the actual
outside air temperature (sensor B).
Fig. 28. Boiler Discharge Temperature vs. Outside
Temperature.
M24556
T775 BUS TERMINALS PROVIDE WIRING CONNECTIONS TO/FROM T775P/L AND T775S.
POWER WITH 24 VAC OR 120/240 VAC AT THE APPROPRIATE TERMINAL BLOCK.
24 VAC POWER TERMINAL BLOCK.
1
2
T775P
T775S
C
NO
NC
C
NO
NC
C
NC
NO
C
NC
NO
T
T
+
–
L1
(HOT)
L2
COM
NO
STAGE
4
COM
NO
COM
NO
COM
NO
STAGE
3
STAGE
2
STAGE
1
C
NO
NC
C
NO
NC
C
NC
NO
C
NC
NO
T
T
+
–
2
120 VAC
COM
NO
1
SENSOR A
1
C
+
C
+
RELAY
3
RELAY
7
RELAY
6
RELAY
5
RELAY
2
RELAY
1
RELAY
4
RELAY
8
120
COM
240
120
COM
240
SENSOR B
T
T
T
T
SENSOR C
2
120 VAC
PUMP
L1
(HOT)
L2
3
3
3
M24880
BOILER DISCHARGE
SETPOINT TEMPERATURE
OUTSIDE AIR
TEMPERATURE
210°
160
170°
180°
190°
20°
70°
60°
50°
40°
30°
200°
