Honeywell T775 Series Application Manual And Cross Reference page 36

T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS
T775L Replacement for S984 Step Controller
(continued)
DIGITAL INPUT
(HEAT/COOL CHANGEOVER)
2 T6031 OR T675A
L1
(HOT)
24 VAC
L2
COOL 2
COM
NO
NO
HEAT
COM
1
HEAT
2
COOL 1
Fig. 39. T775L Wiring Connections for Replacing a S984 Step Controller.
In this replacement application, the T775L provides the following, as described in Table 5:
Component/Function
Sensor
Delay Timer
Throttling Range
Reset
Loads 1 - 5
Auxiliary Pot.
63-7147—3
SENSOR A (C7100D1001)
SENSOR B (SPACE OR OUTDOOR TEMPERATURE)
T
T
T775L
T
T
1
–
+
–
+
4
+
C
RELAY RELAY
4 3
NC NC
C
C
NO
NO
NO NO
C
C
NC NC
RELAY RELAY
1 2
COM
NO
T775 BUS TERMINALS PROVIDE WIRING CONNECTIONS TO/FROM T775L AND T775S.
1
2 SETUP THE CONTROL (T6031 OR T765) SO THAT IT CLOSES ON A TEMPERATURE FALL.
3 POWER WITH 24 VAC OR 120/240 VAC AT THE APPROPRIATE TERMINAL BLOCK.
24 VAC POWER TERMINAL BLOCK.
4
Table 5. T775L Replacement for S684 or S984.
S684 or S984
Series 60, Series 90, Sensor A - Standard 1097 Ohm temperature sensor.
T915, T991, T921, Sensor B - Standard 1097 Ohm temperature sensor; (required only if reset
W902, etc. controller control is used; i.e. a T991B or W902A controller was used.)
See "Temperature Sensors" on page 3.
NOTE: If you are implementing two-sensor reset control, Sensor A must
S400A Use the On Delay and Off Delay programmable parameters of the T775L.
n/a Set the programmable Throttling Range parameter to match the application.
T991B or W902A Reset programming in the T775L provides the reset curve.
(if used)
n/a Program the 5 relays into a single loop.
S964J only The T775L Controller with two T775S Expansion modules allows for up to
12 relay outputs.
NOTE: Fig. 39 is for wiring purposes only. A thorough review
of the existing S984 application is required in order to
determine the capability of the T775 controller
replacement.
1
–
+
4
+
C
3
RELAY
8
NC
C
NO
NO
NO
COM
C
NC
RELAY
5
COM
NO
T775L Replacement
always be the controlled temperature and Sensor B must always
be the controlling temperature. For example, in a reset control
based on outside temperature, Sensor A must be the inside sensor
and Sensor B must be the outside sensor.
36
T775S
3
120 VAC
RELAY
7
NC
C
NO
NO
COOL 4
NO
COM
C
NC
RELAY
6
COOL 3
M28018