SOLID STATE ECONOMIZER SYSTEM
63-2484—03 16
W7213 (CHANGEOVER TERMINAL B)
Connect the B terminal according to the following details:
— 24V power to B: System is in heating mode.
— No power to B: System is in cooling mode.
W7214 (CHANGEOVER TERMINAL O)
Connect the O terminal according to the following details:
— 24V power to O: System is in cooling mode.
— No power to O: System is in heating mode.
SETTINGS AND ADJUSTMENTS
Adjusting Minimum Damper Position
The minimum position potentiometer keeps the outdoor air 
damper from completely closing during system operation to 
allow ventilation.
M7415 and M8405 Damper Actuators 
Adjusting Minimum Position 
(Ventilation) 
The M7415 Damper Actuator is adjusted for desired minimum 
position using a Q709 Actuator Mounted Minimum Position 
Potentiometer and/or a remote S963B1136 Manual 
Potentiometer. The M8405 Damper Actuator has an integral 
thumbwheel for minimum position adjustment. 
M7415 Minimum Position Adjustment 
1. Run actuator to fully closed position and disconnect 24 
Vac from terminals TR and TR1. 
2. Connect minimum position potentiometer to terminals P 
and P1 (T and T1 are disconnected). 
3. Reconnect 24 Vac to terminals TR and TR1 and adjust 
the potentiometer for the desired minimum position. 
4. When the Q709 Actuator Mounted Minimum Position 
Potentiometer is used and a remote potentiometer is 
not connected in series, jumper terminals P and P1 on 
the Q709A.
M8405 Minimum Position Adjustment 
1. Connect the 24 Vac to the actuator at terminals T and X 
(D is not connected).
2. Adjust the thumbwheel on the actuator for desired
minimum position.
Discharge Air Temperature Setpoint 
Adjustment—M7415 Only 
This temperature range can be adjusted either up or down by 
wiring a resistor in series (to increase the setpoint) or in 
parallel (to decrease the setpoint) with the C7150B, 
depending on the application. See Fig. 23 and Fig. 24 for 
explanation.
Fig. 23. Increasing C7150B setpoint. 
Fig. 24. Decreasing C7150B setpoint. 
W7459A,C Solid State Economizer 
Logic Module 
Two potentiometers with small screwdriver slots for 
adjustment are located on the face of the module. 
Minimum Position Adjustment
W7459A ECONOMIZER LOGIC MODULE 
1. Make sure the factory-installed jumper is in place
across terminals P and P1 (terminals T and T1 are
disconnected.
2. Connect 24 Vac at terminals TR and TR1 and adjust the 
potentiometer on the face of the W7459A with a small 
screwdriver for desired minimum position. 
W7459C ECONOMIZER LOGIC MODULE 
1.
Connect 24 Vac at terminals TR and X (D is not con-
nected).
2.
Adjust thumbwheel on motor for desired minimum posi-
tion.
Enthalpy Changeover Setpoint 
Single enthalpy: the enthalpy changeover setpoint is set to 
return the outdoor air damper to the minimum position when 
the enthalpy rises above its setpoint. The enthalpy setpoint 
scale markings, located on the W7459, are A, B, C, D; see 
Fig. 18 for the corresponding control point. The factory-
installed 620-ohm jumper must be in place across terminals + 
and S
R
. 
T
USE 1%, 1/8 W OR HIGHER RESISTOR
M1544C
T1
M7415
C7150
R
RESISTOR VALUE (OHMS) 
681 
2760 
3650 
4420 
4750 
4870 
NO RESISTOR
C7150B SETPOINT °F (°C)
54.5—61.5 (12.5—16.4)
68.4—80.1 (20.3—26.8)
87.4—110.3 (30.8—45.5)
104.7—150 (40.4—65.5)
116—194 (46.7—90)
120—300 (49—149)
50—56 (10—13.3)
T
USE 1%, 1/8 W OR HIGHER RESISTOR
M1545C
T1
M7415
C7150
R
RESISTOR VALUE (OHMS)  
18.2K 
24K 
30K 
NO RESISTOR
C7150B SETPOINT °F (°C)
36—44 (2.2—6.7)
39.5—47 (4.0—8.3)
42—49 (5.6—9.4)
50—56 (10—13.3)