Honeywell T775 Series 2000 Application Manual page 15

Hot Water 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. 13.
SENSOR A
(HOT WATER DISCHARGE)
SENSOR B
(OUTSIDE AIR)
2
+
C
RELAY
4
HOT
WATER
BOILER #1
L1
(HOT)
L2
HOT
WATER
BOILER #2
POWER WITH 24 VAC OR 120/240 VAC AT THE APPROPRIATE
1
TERMINAL BLOCK.
2
24 VAC POWER TERMINAL BLOCK.
Fig. 13. T775R wiring — hot water reset.
T
T
T
T775R
T
RELAY
3
NC
NC
C
C
NO
NO
NO NO
C
C
NC
NC
RELAY RELAY
1 2
T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS
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 setpoint temperature should be 180° F
(82° C). See Fig. 14. Use the alternate Home screens to
check that the effective setpoint is adjusting correctly based
on the outside air temperature (Sensor B).
NOTE: The alternate Home screens do 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).
1
120 VAC
Fig. 14. Boiler discharge temperature setpoint vs. outside
M24872
15
BOILER SETPOINT OUTSIDE AIR
TEMPERATURE TEMPERATURE
210°
200°
190°
180°
170°
160
temperature.
20°
30°
40°
50°
60°
70°
M24873
63-7147—05