C7660 SELECTABLE TEMPERATURE SENSOR
3
63-2670EF—01
Fig. 2. Wiring Connections for C7660 Temperature Sensor.
CAUTION
1. Before beginning installation, disconnect power
supply to prevent electrical shock or equipment
damage.
2. When selecting the location, make sure the
sensor is not exposed to rain, snow or direct
sunlight.
Location
The C7660 Temperature Sensor can be mounted in any
position; however, the sensor must be installed where it is
exposed to freely circulating air but protected from rain and
direct sunlight.
Wiring
Disconnect power supply before beginning installation to
prevent electrical shock or equipment damage. All wiring must
comply with applicable codes and ordinances. Follow the
wiring information furnished by the equipment manufacturer or
see Fig. 2 for typical wiring hookups.
OPERATION
Temperature Change Over Control Setting
The temperature change over setpoint is made by changing
the setting on a 3-position dip switch through the cover of the
sensor. See Fig. 3 for temperature change over settings.
Operation
The C7660 Selectable Temperature Sensor is used with an
economizer control and damper actuator to proportion an
outdoor air damper in a ventilation system.
When outdoor air temperature is below the change over
setpoint, the sensor will provide a 20 mA signal to the
economizer with translate to
OK to economize
positioning the
damper open on a call for cooling. When the outdoor air is
above the change over setpoint, the sensor provides a 4 mA
signal to the economizer which translates to
not OK to
economize
and the outdoor damper drives to minimum
position.
The C7660 temperature sensors replace the control function of
the temperature changeover in the economizer control.
The A, B, C, D potentiometer on the economizer does not
control the changeover point when a C7660 sensor is used in
place of an enthalpy sensor. This potentiometer is only
adjusted when using a C7400 enthalpy sensor for single
enthalpy changeover. For single dry-bulb and differential
enthalpy set the potentiometer to “D”.
L1
(HOT)
L2
1
1
TR1
TR
+
+
+
5
2
4
T1
P1
SO
SR
1
3
T
P
–
620 OHM
RESISTOR
C7660 OUTDOOR
AIR TEMPERATURE
SENSOR
A
B
C
D
TEMPERATURE
SETPOINT
OPEN
MINIMUM
POSITION
MINIMUM
POSITION
24 Vac
MIXED AIR
SENSOR
TR
TR1
TR
TR1
TR
TR1
SEE W7459 SPECIFICATIONS FOR ADDITIONAL WIRING INFORMATION.
POLARITY OF SENSOR IS REQUIRED TO C ON SENSOR TO + ON ECONOMIZER AND – ON SENSOR TO SO ON ECONOMIZER.
ONLY ONE C7660 SENSOR CAN BE USED WITH AN ECONOMIZER FOR SINGLE DRY-BULB CHANGEOVER. DO NOT USE A SECOND
C7660 SENSOR ON THE SR AND SR+ TERMINALS.
W7459 ECONOMIZER PACKAGE MOUNTED ON ACTUATOR
W7459 ECONOMIZER PACKAGE
ACTUATOR
M27635
2
3
2
3