page 2 dwg. no. 21A144441 P02
INSTALLER'S GUIDE
P.I.
COOLING ANTICIPATOR
The cooling anticipator is a fixed-type resistor designed for the
best “on-off” timing of the cooling cycles. Do not remove or re-
place with a resistor of a different value.
CHECKING THERMOSTAT OPERATION
Check control system as follows to make sure that it is function-
ing properly.
The thermostat Heat Anticipator will be damaged if load
is shorted out through improper wiring or testing. Do
NOT short terminals on gas valve to test operation.
1. Set Cool-Heat system switch at “Heat” position. Manually
increase the dial temperature setting until heating plant starts.
Then decrease setting until heating plant stops.
2. Set Cool-Heat system switch at “OFF” position. Increase and
decrease temperature dial setting to make sure that neither the
heating plant nor cooling plant operates.
3. Set Cool-Heat system switch at “Cool”. Manually decrease
the dial temperature setting until the cooling plant starts.Then
increase dial setting to make sure cooling plant shuts off. DO
NOT RESTART FOR AT LEAST 5 MINUTES, AS RAPID
CYCLING WILL DAMAGE THE COOLING UNIT.
4. To check fan switch operation, procedure is as follows:
a. Place fan switch in “Auto” position and Cool-Heat switch at
“Cool”. The fan should cycle with the cooling plant.
b. With fan switch in “Auto” position and Cool-Heat switch at
“Heat”, the fan should be controlled by the fan switch in the
plenum chamber, except in some electric heater installations
(Figure 3C) where fan cycles with heaters.
c. With the fan switch at “On”, the fan should run constantly,
regardless of the position of the Cool-Heat system switch.
5. If, during operation, the burner “on” time is too short or too
long to provide the desired comfort conditions, the cycle may be
lengthened by moving the slider in the direction of the arrow on
the scale or shortened by moving the slider in the opposite direc-
tion. The slider should not be moved more than one-half a scale
division at a time.
FIELD ADJUSTMENTS
(Make Adjustments Only When Required)
The room thermostat is extremely sensitive and is affected by
heat of the hand while adjustments are being made. Therefore,
after any adjustment, allow approximately one hour for the
thermostat to become stabilized to room conditions before final
testing.
DIFFERENTIAL
The differential is factory set and cannot be changed in the field.
Proper switch action is characterized by a positive “snap” of the
armature from “Stop to Stop” as the setting dial is rotated through
the differential.
CALIBRATION
If the thermostat is found to be out of calibration when checked
in its normal operating position after remaining at least one hour
at room temperature, the calibration may be adjusted by means
of the cam rider screw, see Figure 1.
Set the dial at room temperature and selector switch on “Heat.”
Turn the cam rider screw clockwise until the heating plant is off.
Allow the thermostat bimetal to stabilize a few minutes with the
heating plant off. Then slowly turn the cam rider screw counter-
clockwise until the contacts just close and heating plant starts.
All thermostats are set to close the heating contacts at the dial
setting.
THERMOMETER
The ASYSTAT605 thermostat is equipped with a highly sensi-
tive spiral-wound bimetallic thermometer. Normally no adjust-
ments should be required. If, however, the calibration is out of
adjustment, the thermometer may be recalibrated by turning
the screw head directly behind the thermometer element inside
the cover. It is not necessary to remove the crystal on the cover
to make this adjustment.
SYSTEM WIRING DIAGRAMS
(Dotted lines are Field Wiring)
Fig. 3B. Typical Wiring Diagram of
air conditioner and furnace
hook up.
Fig. 3A. Schematic Diagram of
thermostat
Fig. 3C. Typical Wiring Diagram of air
conditioner with air handler
and heater hook up.
