Honeywell W6215 Series Product Data page 8

W6215, W7215, W7460 ECONOMIZER LOGIC MODULES
Differential Enthalpy Changeover Setting
Differential enthalpy control uses two C7400 Enthalpy
Sensors connected to one logic module. The logic module
compares outdoor air to return air instead of to a setpoint as it
does for single enthalpy. Turn the setpoint potentiometer fully
clockwise to the D setting. The logic module selects the lower
enthalpy air (return or outdoor) for cooling; for example, when
outdoor air has lower enthalpy than return air, the outdoor air
damper opens to bring in outdoor air for free cooling.
Exhaust Setpoint
Except for Purge, Shutdown, and Air Change, the exhaust
setpoint determines when the exhaust fan runs based on the
damper position. When the ISI call for exhaust comes, the
module provides a 45 ±15 second delay before exhaust fan
activation. This delay allows the damper to reach the
appropriate position to avoid unnecessary fan overload.
Adjustable Exhaust Setpoint
(W6215A, W7215A, and W7460A only)
The W6215A, W7215A, and W7460A Logic Modules have an
adjustable setpoint. This potentiometer allows the installer to
set the exhaust setpoint at an actual damper position
percentage open from fully closed.
Fig. 7. W6215, W7210, and W7460/C7400 performance characteristics for enthalpy changeover settings.
63-2544—3
CONTROL CONTROL POINT
APPROX. °F (°C)
CURVE
AT 50% RH
A 73 (23)
B 70 (21)
C 67 (19)
D 63 (17)
50
(10)
45 D
(7)
40
(4)
35
(2)
35 40 45 50
(2) (4) (7) (10)
APPROXIMATE DRY BULB TEMPERATURE—°F (°C)
Fixed Exhaust Setpoint (W7215B and W7460B)
The W7215B and W7460B Logic Modules have a fixed
exhaust setpoint. The logic module uses an exhaust setpoint
of 60 percent. When the damper reaches 60 percent open
(from fully closed), the logic module calls for exhaust.
HONEYWELL
SERIES 90
ACTUATOR
(ML9175,
ML9185,
W
M9175,
M9185)
R
B
1 USE 1/2 WATT, 1% RESISTORS OF
SPECIFIED OHM RATINGS (INCLUDED
IN 4074EJM RESISTOR KIT). FOR
MOD IV MOTORS, THE Q7230 MODULE
CAN REPLACE THE RESISTORS.
M11903A
Fig. 6. W7215A used with Honeywell Series 90 Actuator.
85
(29)
80
(27)
75
(24)
70
(21)
65
(18)
60
(16)
A
55
(13)
B
C
A
B
C
D
55 60 65 70 75 80 85
(13) (16) (18) (21) (24) (27) (29)
8
24 VAC HOT
24 VAC COM
3480
Ohms
+
2-10V
536
OUT
Ohms
1
–
665
Ohms
90 95 100 105 110
(32) (35) (38) (41) (43)
90 95 100 105 110
(32) (35) (38) (41) (43)
M11806
W7215A
TR TR1