Honeywell Q682B User manual

169-0431—2
D.F. • Rev. 9-94 • • ©Honeywell Inc. 1994 • Form Number 69-0431—2
T8090A/Q682B
Heating, Cooling, and Heating-Cooling
Thermostat, Wallplate and Subbase
Installation Instructions for the Trained Service Technician.
Preparation
Check thermostat and subbase (if used) suitability for the
heating, cooling, or heating/cooling system. Refer to Table 1.
Assembletoolsrequired:flatbladedscrewdriver,handor
powerdrillwith3/16in.drillbit,wirecutter/stripperorsharp
knife, bubble level or plumb bob and line.
Assure power is off to the heating, cooling, or heating/
cooling system at the main fuse panel. Most buildings have
a separate switch box or circuit breaker for disconnecting
power to the heating and cooling (if applicable) equipment.
This thermostat is compatible with all heating, cooling or
heating/cooling systems when thermostat is powered by bat-
teries. If the thermostat is not powered by batteries, refer to
Table 1 for thermostat and system compatibility information.
aIf thermostat is not compatible with the system being controlled, the system will not operate. No hazard exists. The
thermostat will not be damaged unless it is used to directly control a line voltage system. For proper system operation, a
Honeywell R841 or R8239D1015 Isolating Relay must be added to the thermostat control circuit.
bConsult manufacturer for installation requirements.
TABLE 1—SYSTEM COMPATIBILITY FOR NON-BATTERY POWERED THERMOSTATS.
M3375
Recycling Notice
This control contains mercury in a sealed tube. Do not
place control in the trash at the end of its useful life.
If this control is replacing a control that contains mercury
in a sealed tube, do not place your old control in the trash.
Contact your local waste management authority for in-
structionsregarding recycling and theproper disposal of this
control, or of an old control containing mercury in a sealed
tube.
If you have questions, call Honeywell Inc. at 1-800-
468-1502.
M3375
Type of Heating System to be Controlled Conditions/Compatibility
Electric (Line Voltage)—typical baseboard
and radiant • The R8239D1015 Isolating Relay or R841 Silent Switching Center must be installed in the thermostat control circuit.
a
Fan Coil Unit • Compatible. Assure correct subbase identity selected for fan
control.
Gas—Direct Spark Ignition (DSI),
Intermittent Pilot (IP), and Standing Pilot
(SP)
• Compatible. If not using battery backup, assure that 24V control
transformer common is accessible for connection to thermostat
cable conductor and power to the transformer is not regularly
interrupted by high temperature or limit operation.
Heat Pump • Compatible. Assure correct subbase identity is selected for
fan control and changeover control (O terminal for cool and
B terminal for heat).
Hot Water Zone • Honeywell 2-wire valves are compatible.
• Some non-Honeywell 2-wire valves require an R8239D1015
Isolating Relay in the thermostat control circuit.
a
• Some 3-wire valves require an R8239A1052 Isolating Relay in
the thermostat control circuit.
a, b
Oil • If not using battery backup, assure that the 24V control
transformer common is accessible for connection to thermostat
cable conductor and power to transformer is not regularly
interrupted by high temperature, purge cycle, or limit operation.
Vent Damper • Honeywell damper motors are compatible.
• Some non-Honeywell damper motors require an R8239D1015
Isolating Relay in the thermostat control circuit.
a
Check control
amperage requirement.
Warm Air Zone • Most are compatible.
SUPER TRADELINE®

69-0431—2 2
Installation
WHEN INSTALLING THIS PRODUCT…
1. Read these instructions carefully. Failure to follow
them could cause a hazardous condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for your
application.
3. Installer must be a trained experienced service
technician.
4. After installation is complete, check out product op-
eration as provided in these instructions.
IMPORTANT: An incorrectly leveled subbase will cause
the temperature control to deviate from setpoint. It is
not a calibration problem.
CAUTION
1. Disconnect power supply to prevent electrical
shock or equipment damage.
2. To prevent interference with the thermostat
linkage,keepwirelengthtoaminimumandrun
wires as close as possible to the subbase.
3. Do not overtighten thermostat captive mount-
ing screws because damage to subbase threads
can result.
4. Donot short acrosscoil terminals on relay. This
can burn out the thermostat heat anticipator.
LOCATION
Locate thermostat about 5 ft [1.5m] above the floor in an
area with good air circulation at average temperature.
Donotmountthe thermostat where it maybeaffected by:
—drafts, or dead spots behind doors and in corners.
—hot or cold air from ducts.
—radiant heat from the sun or appliances.
—concealed pipes and chimneys.
—unheated (uncooled) areas behind the thermostat.
Run wires from the heating, cooling or heating-cooling
equipment to the thermostat location.
The number of wires required to connect this thermostat
to the heating, cooling or heating-cooling equipment de-
pends on how the thermostat is powered—by the 24 Vac or
battery, or through the control system. Refer to the Typical
Wiring Diagrams section to determine the number of wires
required for your application.
UNPACK THERMOSTAT
Handle your new thermostat carefully; rough handling
may interfere with its accuracy. Before unpacking, refer to
Fig. 1.
Remove and discard the shipping wrap.
IMPORTANT: Save package of screws and instructions
for homeowner.
Remove thermostat cover by lifting from the bottom. Set
aside cover until needed later.
Carefully remove material protecting mercury switch
bulb.
Loosen two captive mounting screws and separate
wallplate (if provided) from back of thermostat base.
Fig. 1—Unpack thermostat.
12
6
3
9
50 60 70 80
THERMOSTAT
COVER
LIFT
COVER
CAPTIVE
MOUNTING
SCREWS
THERMOSTAT
BASE
M1518
MOUNT WALLPLATE OR SUBBASE
Wall Mounting (Fig. 2)
Holdwallplate or subbasein position onwall as shownin
Fig. 2.
Mark holes on the wall for anchors. Use spirit level to
make sure the wallplate or subbase is level.
Drill 3/16 in. holes and gently tap anchors into holes until
flush with the wall.
Pull wires through large wiring hole in wallplate or
subbase.
Loosely fasten the wallplate or subbase to the wall with
the three screws. Do not tighten screws completely. Care-
fullylevelthewallplateorsubbase(Fig.3)andfirmlytighten
the screws.
Fig. 2—Mounting wallplate or subbase to wall.
M1552A
AUTO OFF COOL HEATON
FAN
R
G
O
W
Y
B
3 SCREW HOLES
WITH PLASTIC
ANCHORS
HEATING/COOLING SUBBASE
3 SCREW HOLES
WITH PLASTIC
ANCHORS
HEATING-ONLY
WALLPLATE
M857

369-0431—2
Fig. 3—Leveling methods for wallplate or
subbase.
AUTO OFF COOL HEATON
FAN
B
O
W
Y
R
G
M1555
SPIRIT LEVEL
PLUMB
LINE
PLUMB
BOB OR
WEIGHT
Outlet Box Mounting (Fig. 4)
Use a horizontally mounted outlet box if possible. If a
verticaloutletboxisused, mount the wallplate or subbaseon
a 193121A (beige) or 202689A (white) Cover Plate Assem-
bly (ordered separately). Follow the instructions provided
with the cover plate assembly.
Align wallplate or subbase mounting holes on the outlet
box and loosely fasten with two screws.
Carefully level the wallplate or subbase (Fig. 3) and
firmly tighten the screws.
WIRE WALLPLATE OR SUBBASE
Follow the instructions provided by the heating, cooling
or heating-cooling equipment manufacturer. If not avail-
able, refer to Typical Wiring Diagrams section at the end of
this publication.
Disconnect power supply before making wiring connec-
tions to prevent electrical shock or equipment damage.
NOTE: All wiring must comply with local electrical codes
and ordinances.
This thermostat clock can be powered by 24 Vac trans-
former with battery backup, 24 Vac transformer only or bat-
tery only, or through the control system. See Figs. 15 through
19 for hookup diagrams of typical powering applications.
Wallplate (Heating or Cooling Systems)
Refer to Fig. 5 and strip thermostat wire insulation as
necessary.
Forheating-only systems,connectwirestoR,Wand C(if
applicable) terminals. For cooling-only systems, connect
wires R, Y and C (if applicable) terminals. Firmly tighten
screws. See Fig. 20.
Push excess wire back into the wall.
Plug the hole in the wall with nonhardening caulk, putty,
or nonflammable insulation to prevent drafts from affecting
thermostat operation.
Subbase (Heating-Cooling Systems)
Refer to Fig. 5 and strip the thermostat wire insulation as
necessary.
Fig. 4—Mounting wallplate or subbase on horizontal outlet box.
M1554A
B
O
W
Y
R
G
VERTICAL
OUTLET
BOX
ADAPTER
RING
1
2
NOT INCLUDED WITH UNIT.
ACCESSORY PARTS AVAILABLE.
SUBBASE OR
WALLPLATE
1
2
2
COVER
PLATE
MOUNTING
SCREWS (2)
M1553A
EXISTING
HORIZONTAL
OUTLET BOX
HEATING/
COOLING
SUBBASE
AUTO OFF COOL HEATON
FAN
R
G
O
W
Y
B
EXISTING
HORIZONTAL
OUTLET BOX
WALLPLATE
R
W
M856

69-0431—2 4
Fig 5.—Methods of connecting terminals. Connect the wires to corresponding terminals on the subbase. If labels do not agree with your new subbase, refer
to Table 2, Figs. 21-22, and the installation instructions
furnished with the subbase.
NOTE: If wiring a dual transformer system, only the O or
the B terminal may be used.
Push excess wire back into the wall.
Plug the hole in wall with nonhardening caulk, putty, or
nonflammable insulation to prevent drafts from affecting
the thermostat operation.
TABLE 2—TERMINAL DESIGNATIONS.
BARRIER
FOR WRAPAROUND
CONNECTION—
STRIP 7/16 in. [11 mm]
FOR STRAIGHT
CONNECTION—
STRIP 5/16 in. [8 mm]
M1556B
Subbase Terminal Control Function
R Control transformer power.
RcLine side of 24V power supply; cooling side, 2 transformer heat-cool system.
RhLine side of 24V power supply; heating side, 2 transformer heat-cool system.
W Heating control circuit.
Y Cooling control circuit; jumper to W for heat pump compressor control if no
P terminal on subbase.
G Fan control circuit.
C Clock control (transformer common).
O Cooling damper or changeover/reversing valve, makes continuously in cool.
B Heating damper or changeover/reversing valve, makes continuously in heat.
P Heat pump contactor; P terminal on some models only.
MOUNT THE THERMOSTAT
Note the tabs on the top inside edge of the thermostat
base. These tabs fit the slots molded into the top of the
wallplate or subbase.
Hang thermostat base on wallplate or subbase.
Insert the two captive mounting screws located in the
bottom corners of the base (Fig. 6).
Firmly tighten the screws.
INSERT CLOCK OPERATION
Power is supplied to the clock by the 24 Vac transformer
or two AAA alkaline batteries (included), or by the heating
or cooling control circuit. Backup batteries may be installed
to supply power to the clock if power is interrupted when
using 24 Vac powering method.
Install the batteries in the thermostat as shown in Fig. 7.
Once a year or when batteries are dead, replace with two
new AAA alkaline batteries. We recommend Energizer®
batteries.
Fig. 6—Thermostat mounting.
TAB (2)
MOUNTING SLOT (2)
CAPTIVE
MOUNTING SCREWS
THERMOSTAT
BASE
WALLPLATE
OR SUBBASE
35
30
25
20
10
12
11
10
9
8
7
6
5
4
3
2
1
12
11
10
9
8
7
6
M8584

569-0431—2
BATTERY LOCATION FOR
(2) AAA BATTERIES;
INSTALL WITH POSITIVE
ENDS UP
M7188
Fig. 7—Insert clock batteries. Fig. 8—Set clock.
TIME
INDICATOR
ARROW
MINUTE
HAND
M8561
SET CLOCK
Adjust the clock by moving the minute hand in a clock-
wise direction. Do NOT reverse the minute hand.
Whentime iscorrectlyset,the timeindicatorarrow(Fig. 8)
mustpointtothe correct time and the corresponding daytime
(light) or nighttime (dark) portion of the program dial.
SET HEAT ANTICIPATOR
Adjust the heat anticipator lever to match the current
ratingoftheprimarycontrol forthepropercycle rate(Fig.9).
Adjustable anticipation must be set for total current of heat
and fan control.
The current rating is usually stamped on the control or
valve (Fig. 10), or a setting may be given in the device
instructions.
If no current rating or heat anticipator setting is given,
measure the current with an ammeter. Proceed with the
following steps.
Remove thermostat from wallplate or subbase. Connect
an ac ammeter of appropriate range (about 0A to 2A) be-
tween the R and W terminals on the wallplate or subbase
except in electric heat and heat pump systems.
Let the system operate for one minute.
Adjustthe heat anticipator leverto match the numberthat
reads on the ammeter.
Fig. 9—Adjust heat anticipator.
M7317
ANTICIPATOR
SCALEPLATE
ANTICIPATOR
SETTING LEVER
Fig. 10—Current rating of primary control.
V8043E 1004 4
24V 50/60CY
.32 AMP @ 60CY
8406
24 Vac 50/60 Hz
0.4 AMP
30 VAC
0.2 AMP
T
F
T
F
OIL BURNER CONTROL
SHOWS
CURRENT
DRAW
SHOWS LOW
VOLTAGE
M6116A
FROM MAIN
FUEL SUPPLY
SHOWS
VOLTAGE
RATING TO
BURNER
SHOWS
ANTICIPATOR
SETTING
TYPICAL GAS VALVE
ZONE VALVE
SHOWS
VOLTAGE
RATING
SHOWS
ANTICIPATOR
SETTING

69-0431—2 6
ATTACH THERMOSTAT COVER
Make sure the packing inserts in the thermostat base are
removed.
Place the two tabs on the upper edge of the cover into the
mounting slots in the thermostat base (Fig. 11).
Swing the cover downward until it catches at the bottom
of the base.
Fig. 11—Attach cover.
Thesubbase fan switch controlsfan operation as follows:
ON: Fan operates continuously.
AUTO: Fan operates with cooling equipment as con-
trolled by the thermostat or with the heating equip-
ment as controlled by the plenum switch. In electric
heat, heat pump and fan coil systems, the fan is
controlled by the thermostat in heating and cooling.
To switch positions, use thumb or index finger to slide
lever to desired position. Switch lever must stop in detent
over the desired function indicator mark for proper circuit
operation.
Checkout
CAUTION
DoNOT check operation by shortingacross termi-
nals of system controls. This will damage the heat
anticipator.
HEATING-ONLY SYSTEM
Turn on power to the furnace.
Pushboth temperature setting leverstogether at least5°F
[3°C] above room temperature. The main burner should
come on. The fan will start when the furnace heats up.
Move both levers 5°F [3°C] below room temperature.
The burner should shut off.
Operate the entire heating system at least one complete
cycle.
If thermostat fails any test, refer to the Troubleshooting
Guide in the Owner’s Manual.
Reset both temperature setting levers to the desired
temperatures.
COOLING-ONLY SYSTEM
Turn on power to the cooling equipment.
Pushboth temperature setting leverstogether at least5°F
[3°C] below roomtemperature. The cooling equipment will
operate, and the fan will start. Allow for any time delay that
may be built into the compressor control circuit.
NOTE: To avoid compressor damage, do not operate the
systemwhenoutdoortemperatureis below 50°F [10°C].
Refer to manufacturer recommendations.
Move both levers 5°F [3°C] above room temperature.
The cooling equipment and the fan should shut off.
Operate the entire cooling system at least one complete
cycle.
If thermostat fails any test, refer to the Troubleshooting
Guide in the Owner’s Manual.
Reset both temperature setting levers to the desired
temperatures.
HEATING/COOLING SYSTEM
Turn on power to the furnace and cooling system.
Place the system switch lever to HEAT and fan switch
lever to AUTO.
12
6
3
9
50 60 70 80
M1519
SET TEMPERATURE CONTROL LEVERS
The two levers on top of the thermostat control the low
and high temperatures for energy savings and comfort con-
trol (Fig. 12). The lever on the left (blue mark) controls the
lowertemperature.The lever on the right (redmark)controls
the higher temperature.
We recommend pushing the levers together at an appro-
priate temperature for either heat or cool until the occupant
programs the thermostat and makes the final temperature
selections.
Fig. 12—Temperature control levers.
50 60 70 80
HIGH TEMPERATURE
(RED MARK)
SET LEVER
LOW TEMPERATURE
(BLUE MARK)
SET LEVER
M859
SET SUBBASE SWITCHES (IF APPLICABLE)
The subbase system switch controls system operation as
follows:
HEAT: Heating system is controlled by the thermostat.
Cooling system is off.
COOL: Cooling system is controlled by the thermostat.
Heating system is off.
OFF: Both the heating and cooling systems are off. If the
fan switch is in the AUTO position, the fan is also off.

769-0431—2
Pushboth temperature setting leverstogether at least5°F
[3°C] above room temperature. The main burner should
come on. The fan will start when the furnace heats up. (If
central electric heat, fan coil or heat pump system, fan starts
immediately.)
Move both levers 5°F [3°C] below room temperature.
The burner should shut off.
Placethesystemswitchlever toCOOLand thefanswitch
leverto AUTO. The cooling equipment will operate, andthe
fan will start. Allow for any time delay that may be built into
the compressor control circuit.
NOTE: To avoid compressor damage, do not operate the
systemwhenoutdoortemperatureis below 50°F [10°C].
Refer to manufacturer recommendations.
Move both temperature setting levers together at least
5°F[3°C]aboveroom temperature. The coolingequipment
should shut off.
Place the fan switch to ON. The fan should run continu-
ously with the system switch in any position.
Place the system switch to OFF. Move both temperature
setting levers to various positions. The heating and cooling
systems should not operate.
Operate the entire system for at least one complete cycle
with the system switch at COOL and one complete cycle
with the switch at HEAT.
If thermostat fails any test, refer to the Troubleshooting
Guide in the Owner’s Manual.
Reset both temperature setting levers to the desired
temperatures.
Leave Owner’s Manual and assistance information in a
convenient place for the building occupant or provide with
other appliance manuals.
Calibration
THERMOMETER
The thermometer in your thermostat was accurately cali-
brated at the factory. The thermometer should need adjust-
mentonly if it hasbeendroppedorshifteddue to mishandling.
If the setpoint lever and the thermometer reading do not
agree:
1. Remove the thermostat cover by pulling up from the
bottom of cover until it clears the mounting slots.
2. Set the thermostat cover on a table near an accurate
thermometer.
3. Allow five minutes for cover thermometer to sense
area temperature; compare the readings. Be careful not to
touch thermometer or breathe on it.
4. If the readings are the same, replace cover and put the
system into operation.
5. Ifthe readings are different, insert a small screwdriver
in the thermometer and turn it until the thermometers have
the same reading. See Fig. 13.
6. Replace thermostat cover and put the system into
operation.
NOTE: Radiant heat from your hands will offset the ther-
mometer reading. After making each adjustment, wait
fiveortenminutesforthethermometer to stabilize before
comparing.
THERMOSTAT
This thermostat was calibrated at the factory and should
not need recalibration in the field. If recalibration seems
necessary, first assure wallplate or subbase is accurately lev-
eled. Then check thermometer calibration.
To check thermostat calibration, allow several hours of
operation after installation. Then read thermometer and
remove cover. Push temperature levers together to a setting
below room temperature. Slowly move them up the scale
together until the mercury slides across the tube. If the
thermometer reading and the high temperature lever posi-
tion are approximately the same at the instant the mercury
moves to the other end, no recalibration is needed.
If calibration is necessary, proceed as follows:
1. Remove the cover.
2. Place open-end calibration wrench, part no. 104994A
(ordered separately), on the hex nut under the bimetallic coil
controlled by the red lever. See Fig. 14. Hold lever so it does
not move, and gently turn the wrench clockwise until
the mercury rests securely in the right end of the tube.
3. Put the thermostat cover on and wait 10 minutes.
4. Read the thermometer. Then remove the cover. Mov-
ing both levers, place the HIGH lever at the thermometer
reading. Hold lever so it does not move and gently turn the
wrench counterclockwise until the mercury just slides
totheleft end of the tube but no farther.Trytodothisquickly
so the heat from your hands does not affect the thermostat.
5. Repeat this procedure for the blue lever.
Fig. 13—Thermometer calibration.
.35
.30
.25
.20
.10
M8583
ANTICIPATOR
SETTING
LEVER
ANTICIPATOR
SCALEPLATE
CALIBRATION
WRENCH
Fig. 14—Use of 104994A calibration wrench.
M5128
INCREASE

69-0431—2 8
Typical Wiring Diagrams
Fig. 15—Typical hookup for clock powered by
separate 24 Vac transformer.
Fig. 17—Typical hookup for clock powered by
system transformer. Clock powered by battery
when system is not powered (e.g., power to
system is off or interrupted).
L1
(HOT)
L2
1
L1
(HOT)
L2
1
CCRW
HEAT
RELAY
CLOCK
THERMOSTAT
SUBBASE
1
2
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
BATTERY BACKUP MAY BE USED IF POWER TO
CLOCK IF INTERRUPTED. M1512B
BATTERY
Fig. 16—Typical hookup for clock powered by
two AAA alkaline batteries only.
L1
(HOT)
L2
1
1POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
CCRW
HEAT
RELAY
CLOCK
THERMOSTAT
SUBBASE
M1511A
BATTERY
L1
(HOT)
L2
1
CCRW
HEAT
RELAY
CLOCK
THERMOSTAT
SUBBASE
1
2
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
M1513A
BATTERY
Fig. 18—Typical hookup for clock powered
through control system. Clock powered by
battery when heating or cooling equipment is
on; clock takes power from system when
heating equipment is off.
L1
(HOT)
L2
1
1
L1
(HOT)
L2
1
HEAT
RELAY
COMPRESSOR
CONTACTOR
CLOCK
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
JUMPER RH-RC TERMINALS WHEN ONE TRANSFORMER
POWERS BOTH HEATING AND COOLING.
FOR POWER STEALING ON HEATING, JUMPER
C-RH AND C-W TERMINALS.
2
3
32
THERMOSTAT
BATTERY
SUBBASE
CCRHRC WY
M1514C

969-0431—2
Fig. 19—Typical hookup for clock powered through control system. Clock powered by battery when
heating or cooling equipment is on; clock takes power from system when cooling equipment is off.
L1
(HOT)
L2
1
1
L1
(HOT)
L2
1
HEAT
RELAY
COMPRESSOR
CONTACTOR
CLOCK
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
JUMPER RH-RC TERMINALS WHEN ONE TRANSFORMER
POWERS BOTH HEATING AND COOLING.
FOR POWER STEALING ON HEATING, JUMPER
C-RC AND C-Y TERMINALS.
2
3
32
THERMOSTAT
BATTERY
SUBBASE
CCRHRC WY
M720A
Fig. 20—Internal schematic and typical hookup for T8090A Thermostat/191108AJ Wallplate in heating-
only system.
H
FALL
C
L1
(HOT)
L2
1
1
H
FALL
C
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
HEAT
ANTICIPATOR
HEAT
ANTICIPATOR
CCRWY
HEAT
RELAY
CLOCK
THERMOSTAT
WALLPLATE
M1515A

69-0431—2 10
Fig. 21—Internal schematic and typical hookup for T8090A Thermostat/Q682B Subbase in heating-
cooling system; auto fan on call for heating or cooling.
HEAT
OFF
COOL
ON
AUTO
HC
H
C
FAN
SWITCH
T8090A
THERMOSTAT
Q682B
SUBBASE
M1516B
HEAT
ANTICIPATOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
WITH NO O TERMINAL LOAD, THERMOSTAT CURRENT DURING HEATING CYCLE VARIES DEPENDING ON WHETHER
FAN SWITCH IS IN THE ON OR AUTO POSITION. HEATER SHOULD BE SET FOR COMBINED CURRENT LEVEL OF HEAT
RELAY AND FAN RELAY COILS. WITH O TERMINAL LOAD, SET THERMOSTAT HEAT ANTICIPATOR TO ITS MAXIMUM
SETTING AS COOLING ANTICIPATOR IN SERIES WITH O TERMINAL LOAD PROVIDES HEAT ANTICIPATION IN THE
HEATING CYCLE. (LIMIT THE THERMOSTAT HEATING LOAD CURRENT TO 0.8 AMPS TO ASSURE GOOD PERFORMANCE.)
IN HEAT PUMP SYSTEMS, CONNECT P TERMINAL TO HEAT PUMP CONTACTOR; DO NOT CONNECT W OR Y
TERMINAL TO SYSTEM CONTROLS.
1
COOL
ANTICIPATOR
HEAT
ANTICIPATOR
SYSTEM SWITCH
HEAT
OFF
COOL
BO
G
Y
WR
COOL
DAMPER
HEAT
DAMPER
FAN
RELAY
HEAT
RELAY
COMPRESSOR
CONTACTOR 1L2
L1
(HOT)
2
2
CLOCK
C P
C3
3
FALL
FALL

11 69-0431—2
Fig. 22—Internal schematic and typical hookup for T8090A Thermostat/Q682B Subbase with Rcand Rh
terminals jumpered for single transformer system; O and B terminals connected for control of dampers
or changeover valves.
HEAT
OFF
COOL
ON
AUTO
HC
FAN
SWITCH
T8090A
THERMOSTAT
Q682B
SUBBASE
M1517A
HEAT
ANTICIPATOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
ON SINGLE TRANSFORMER SYSTEMS (RH-RC JUMPERED) WITH O TERMINAL LOAD, SET THERMOSTAT HEAT
ANTICIPATOR TO ITS MAXIMUM SETTING AS COOLING ANTICIPATOR IN SERIES WITH O TERMINAL LOAD
PROVIDES HEAT ANTICIPATION IN THE HEATING CYCLE. (LIMIT THE THERMOSTAT HEATING LOAD CURRENT
TO 0.8 AMPS TO ASSURE GOOD PERFORMANCE.)
FIELD INSTALLED JUMPER.
1
COOL
ANTICIPATOR
HEAT
ANTICIPATOR
SYSTEM SWITCH
HEAT
OFF
COOL
OGY
W
RH R RC
COOL
DAMPER
HEAT
DAMPER
FAN
RELAY HEAT
RELAY
COMPRESSOR
CONTACTOR
1L2
L1
(HOT)
2
2
CLOCK
C
C
3
3
FALL
HC
FALL

Automation and Control Solutions
Honeywell International Inc. Honeywell Limited—Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422-4386 Scarborough, Ontario M1V 4Z9