T775 Application Replacement Examples; T775M2030 Replacement For W973A Logic Panel - Honeywell T775 Series 2000 Application Manual

T775 APPLICATION
REPLACEMENT EXAMPLES
This section describes how a T775 Series 2000 Electronic
Stand-Alone Controller is wired and programmed to replace
various older generation Honeywell devices.
COOL 2
COOL 1
1
L1
(HOT)
T1
L2
T2
M954 MOTOR
(HEATING)
C7046
DISCHARGE
SENSOR
(OPTIONAL) PLENUM
FAN CONTROL
4
1
L1
FAN RELAY
(HOT)
L2
4
FAN START
RELAY
NOTE: The T775M2030 Replacement for W973A Logic Panel continues on the next page.
T675A COMPRESSOR LOCKOUT
W973A
2
2
2
MOD-HEAT
WH BH RH
W1
B1
R1
SENSOR STAT
C +20 H
T T1 3 4 2 5
3 4 2 5
T7067 THERMOSTAT
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
W973A SHOWN. W973B HAS 3 HEAT AND 3 COOL STAGES.
2
3 USE MODULATING AND/OR OUTPUT RELAYS DEPENDING ON APPLICATION.
4 USE FAN START RELAY AND/OR PLENUM FAN CONTROL FOR AUTOMATIC FAN OPERATION IN
HEATING MODE.
Fig. 42. W973A wiring connections (pre-existing control).
T775 SERIES 2000 ELECTRONIC STAND-ALONE CONTROLLERS
T775M2030 Replacement for W973A
Logic Panel
This replacement example illustrates how a T775M2030 is
configured to replace a two-stage Heat and two-stage Cool
W973A Logic Panel.
• Fig. 42 illustrates the wiring connections for the W973A
Logic Panel.
• Fig. 43 and Table 2 on page 35 illustrate the wiring and
configuration of the T775M2030 controller.
T675A HIGH LIMIT
HEAT 1
COOL 1
MOD-COOL
3
RC BC WC
24V ECONO
N
1 T R T R W B Y R
1
6
L1
7
(HOT)
8
L2
33
L1
1
L2
(HOT)
HEAT 1
HEAT 2
M954 MOTOR
(COOLING)
1
L1
R1
(HOT)
T1
B1
L2
T2
W1
M955 MOTOR (ECONOMIZER)
R1
T1
R W
W1
T2
B1
MIN. POSITION
POT ENTIOMETER
W R B
1 2 3
H205 OUTSIDE
AIR CHANGEOVER
1
1
L1
(HOT)
L2
M24562
63-7147—05