Honeywell Design and Application User Manual

Section 17 - Retrofit and Upgrades
63-8594-02 Honeywell Economizers 186
Before: W973 With H205 Control
The W973 was a sequencing panel for Single zone systems that could provide multiple
modulating or two-position output stages of control plus a modulating economizer. A dry bulb
high limit and a H205 enthalpy control were widely used in the economizer circuit. If they are
replaced with a solid state economizer controller, the actuator for the dampers need to be
replaced. In the replacement illustration on the next page a direct coupled actuator is used.
60
180
90
1
70
1
6
15
140
1
30
1
2
0
11
0
1
0
0
F
8
0
70
3 4 2 5
1
T7067 THERMOSTAT
LOW O.A. AMBIENT
COMPRESSOR
LOCKOUT STAT
(OPTIONAL)
W973 SINGLE ZONE PANEL
M13850
2
1
HEAT
2
1
COOL
MOD-HEAT
LOOC3TAEH3
MOD-COOL
WH BH RH RC BC WC
SENSOR STAT 24 VAC ECONO
T1T
C+20H N
TR TR W YBR34251
MINIMUM
POSITION
CONTROL
W
R
60
100
140
120
80
40
°F
H205 ENTHALPY
CONTROL
1 2 3
SERIES 90 MIXED AIR
DAMPER ACTUATOR
W
R
B
T1
T2
24 VAC
TRANSFORMER
R
W
COOL 3
COOL 1
COOL 2
COOLING
STAGES

Honeywell Design and Application Specifications

General

Brand	Honeywell
Model	Design and Application
Category	Controller
Language	English