Stage With Pump Output And Reset (Continued) - Honeywell T775 Series 2000 Application Manual

T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS

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.
See Fig. 27.
L1
(HOT)
L2
STAGE
4
STAGE
1
STAGE
2
STAGE
3
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. It shows the tem-
perature only at the moment the button is pressed.
From the Home screen, use the  button to verify
1.
the setpoint temperature for each output.
2. Then, press the HOME button to view the actual
outside air temperature (Sensor B).
63-7147—05
SENSOR B
SENSOR A
SENSOR C
T
T
T
T775P
T
T
T
–
1 +
3
+
C
RELAY RELAY
4 3
NC
NC
COM
C
C
NO
NO
NO
NO
NO NO
COM
C C
NC NC
RELAY RELAY
1
COM
1 T775 BUS TERMINALS PROVIDE WIRING CONNECTIONS TO/FROM T775P/L AND T775S.
2 POWER WITH 24 VAC OR 120/240 VAC AT THE APPROPRIATE TERMINAL BLOCK.
3 24 VAC POWER TERMINAL BLOCK.
Fig. 27. T775P wiring — 4 stage with pump output and reset.
–
1 +
3
+
C
2
120 VAC
RELAY
8
NC
COM
C
NO
NO
RELAY
2
NO
PUMP
COM
NO
BOILER DISCHARGE
SETPOINT TEMPERATURE
Fig. 28. Boiler discharge temperature vs. outside
22
T
T
T775S
120 VAC
RELAY
7
NC
C
NO
NO NO
C C
NC NC
RELAY
5 6
L2
L1
(HOT)
OUTSIDE AIR
TEMPERATURE
210° 20°
200° 30°
190° 40°
180° 50°
170° 60°
160 70°
temperature.
2
M24556
M24880