Honeywell Design and Application Technical Reference Manual page 66

Section 6 - W7459 Economizer Module
8
UNOCCUPIED
ST6008
TIMER
OCCUPIED
Y1
Y2
W2
W1
7
RH
RC
T7300 OR T874
THERMOSTAT
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2 MOTOR SPRING-RETURNS CLOSED WHEN FAN IS NOT RUNNING.
3
ENSURE THAT EQUIPMENT TRANSFORMER IS SIZED TO HANDLE THE EXTRA LOAD OF THE ECONOMIZER AND ACTUATOR.
1S IS AN ELECTRONIC SWITCH THAT CLOSES WHEN POWERED BY A 24 VAC INPUT.
4
5 RELAYS 1K AND 2K ACTUATE WHEN THE ENTHALPY SENSED BY THE C7400 IS HIGHER THAN THE ENTHALPY SETPOINT A-D.
6 FACTORY INSTALLED 620 OHM, 1 WATT, 5% RESISTOR SHOULD BE REMOVED ONLY IF A C7400 ENTHALPY SENSOR
IS ADDED TO S R AND + FOR DIFFERENTIAL ENTHALPY.
7 FOR T7300 ONLY.
8 WITH T7300, USE CONTACTS A 1 AND A 2 INSTEAD OF S7005 TIMER.
W7459A/C7400 used in two-stage cooling system with
single enthalpy changeover and with M7415 Actuator
63-8594-02 Honeywell Economizers
TR
C7400
+
OUTDOOR
AIR
S O
ENTHALPY
S
SENSOR
S R
620 OHM
6
RESISTOR
1
T
C7150B MIXED
P
AIR OR
C7046A
DISCHARGE
AIR SENSOR
W
T6031 AMBIENT
LOCKOUT
R
CONTROL
50 F SETPOINT
G
X
W7459A ECONOMIZER PACKAGE
TR1
+
+
5
1K
5
2
1S
2K
4
3
T1
1S1
P1
MINIMUM POSITION
ADJUSTMENT
C
Y1
Y2
W2
W1
FDR
G
FDR
R
HVAC EQUIPMENT
TERMINAL STRIP
60
M7415 ACTUATOR
TR
24 VAC
TR1
4
T
MIXED
AIR
T1
SENSOR
P1
MINIMUM
P
POSITION
M7415
COOL 1
24 VAC
COOL 2
SENSOR
HEAT 2
MIN
POS
HEAT 1
FAN
DELAY
RELAY
FAN 1 3
L2
2
L1
(HOT)
TR
TR1
T
T1
P1
P
M10115C