User Guide

O N E ZO N E M O D E
O F F
O N
G
RY
W1
C
ZONE THERMOSTAT
#1
Commercial Grade
Thermostat
UNOCC / OCC
SUPPLY AIR SENSOR OPERATIONS AND ONE ZONE FEATURE CONTROL
The One Zone feature allows the homeowner to
control all the zones from a single thermostat by using
an optional switch connected to the One Zone
terminal shown below. A homeowner can switch to
One Zone control when they leave for vacation or as a
night setback mode, and the Zone 1 thermostat will
control all zones. All zone dampers will respond to the
Zone 1thermostat. Use Part # VAC.
One Zone can also be used in commercial
applications with a programmable thermostat in Zone
1 and non-programmable thermostats in all other
zones, thus satisfying the requirements of California
Title 24.
Substantial energy savings and equipment protection
can be obtained with proper use of the One Zone
feature and the supply air sensor.
A Supply Air Sensor can be used to limit supply air
temperatures and prevent over heating of the
equipment during the heating cycle or coil freeze-
up during cooling cycles. Wire the sensor as
shown below and set dip switch #7 to the ON
position. (See Page 2)
The Supply air sensor installs into the supply air
plenum or downstream of the evaporator coil or
heat exchanger and monitors the discharge air
temperature in heating and cooling modes. The
actual temperature is relayed backed to the
microprocessor. When the temperature exceeds
or falls below the HEAT or COOL limit set points,
the microprocessor will de-energize all HEAT or
COOL outputs for a minimum of 3 minutes. It also
energizes the FAN, if it is not already running, to
help dissipate the heat or warm up the evaporator
coil. Refer to the Data sheet that comes with the
Supply Air Sensor.
There is no differential built in to the sensor! Once
the supply air temperature rises or falls to a safe
value and, the 3 minute time delay has expired,
the microprocessor will restore the HEAT or
COOL outputs. The FAN will de-energize or stay
running, depending on the mode of operation
and the application.
TM
Forced Air Zone Controls
11
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX [phone] E-Mail- [e-mail]
110
120
130
140
150
160
170
HIGH TEMP
LIMIT
34
37
40
43
46
49
52
LOW TEMP
LIMIT
Adjustable Heating & Cooling limit potentiometers
Supply air temperature sensor.
Model
SAS
2
1
SUPPLY
AIR
SENSOR
SENSOR
One Zone Mode
via the Zone 1
Thermostat
ZONE 1
T'STAT
C
W/E
Y
R
G
ONE
ZONE
O/B
C
W/E
Y
R
G
ONE
ZONE
ZONE 1
T'STAT
O/B
See Technical Bulletin #TB-212
for exact wiring connections.