W7459A, B, C And D - Honeywell Design and Application Technical Reference Manual

Section 6 - W7459 Economizer Module
ENTHALPY
CHANGEOVER
SETPOINT DIAL
B
A
MININUM
POSITION DIAL
MINIMUM
(W7459A AND D
POSITION
ONLY)
LIGHT IS
ILLUMINATED IF
OPEN
OUTDOOR AIR
IS USEABLE FOR
FREE COOLING
NOTE: USE SMALL SCREWDRIVERS ON THE POTENTIOMETERS.
DO NOT USE EXCESSIVE FORCE!
W7459A
W7459A or D - Uses inputs from mixed or
discharge air temperature sensors, C7150 or
C7046; enthalpy sensor C7400; and optional
remote minimum position potentiometer
Q709A or S963B. The W7459D is identical to
the W7459A except for the addition of a built-
in enthalpy high limit. Refer to high limit
function in Table 2 and at the end of this
section. Use both modules with M7415
motors.
There are four separate W7459 enthalpy logic
modules for use with various M74XX series
actuators. All provide enthalpy control of
mixed air. The W7459B is designed for use
with a legacy Honeywell direct digital
controller. The W7459C uses a SPST input for
the mixed air sensor.
63-8594-02 Honeywell Economizers

W7459A, B, C and D

TRANSFORMER
TR
TR1
(POWER) TERMINALS
C
OUTSIDE AIR
S O
+
SENSOR TERMINALS
D
RETURN AIR
S R
+
SENSOR TERMINALS
5
COOLING SWITCHING
CONTROLLED FROM
1 2
COOLING STAT
4
3
MIXED OR SUPPLY
T1
T
AIR SENSOR
REMOTE MINIMUM
P1
P
POSITION POTENTIOMETER
M23894A
NOTE: USE SMALL SCREWDRIVERS ON THE POTENTIOMETERS.
DO NOT USE EXCESSIVE FORCE!
W7459B - Used with Honeywell W7401 Logic
Panel, enthalpy sensor C7400 or minimum
position potentiometer Q709A or S963B. Use
with M7405.
NOTE: USE SMALL SCREWDRIVERS ON THE POTENTIOMETERS.
DO NOT USE EXCESSIVE FORCE!
W7459C - Uses input from SPST mixed or
discharge air control and enthalpy sensor
C7400. Used with M8405.
56
TR TR1
B C
S O
+
A
D
S R
+
M3 3
1
2
MINIMUM
POSITION
M1
M2
OPEN
P1
P
W7459B
TR
TR1
B C
S O
+
A
D
S R
+
5
2
1
X TERMINAL IS USED
WITH A ST6008 TIMER
4
3
FOR OCCUPIED/
UNOCCUPIED
X
MIXED AIR CONTROL
(T675/T6031)
CONNECTED TO
D
6
TERMINALS 6 AND D
W7459C
M23895A
M23896A