Honeywell T841A, T841A1498, T841A1423, T841A1464, T841A1308 User Manual

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T841A Heating-Cooling Heat Pump Thermostat
APPLICATION
The T841A Heating-Cooling TRADELINE® Thermostat provides 24 Vac control of two-stage heating and one­stage cooling in heat pump systems, using manual changeover. This thermostat provides SYSTEM switch selections of EM. HEAT-HEAT-OFF-COOL and FAN switch selections of AUTO-ON. See Fig. 1. See Table 1 for T841A TRADELINE® specifications.
Table 1. T841A TRADELINE® Specifications.
OS Number
T841A1308 EM. HEATa,
T841A1316 G, R, E, L, X
T841A1423bEM. HEAT,
T841A1464 T841A1498 EM. HEAT Stage 2 fixed,
T841A1506
a
EM. HEAT LED also indicates compressor malfunction.
b
Premier White® color.
c
Sold only in Australia: degrees C.
d
CHECK LED indicates compressor malfunction.
LED
Indication Changeover
AUX. HEAT
AUX. HEAT,
d
CHECK
b,c
b
FRONT OF DEVICE
Manual Cool or Heat
Heat
Anticipation
Stage 2 fixed, 0 to 1.5A
Stage 2 adjustable, 0.1 to 1.2A
0 to 1.5A
80
80
70
70 60
60
50
50
CHECK
EM. HEAT HEAT OFF COOL
SYSTEM SWITCH
FAN
EM. HEAT AUX. HEAT
FAN SWITCH
Fig. 1. External view of T841A.
Test holes are provided on the front of the thermostat to accommodate test meter probes without removing the thermostat from the wall. Remove the cover of the thermostat to expose the test holes, which are labeled to correspond with the terminals on the back of the thermostat.
Terminal
Designations Remarks
G, R, W2, E, L, B, X, Y, O
W2, B, W1, Y1, O W3, G, R, W2, E, L, B, X, Y, O
G, R, W, H, B, X, O, Y
COVER
THERMOMETER
SET POINT SCALE
LED (UP TO THREE)
INSTALLATION INSTRUCTIONS
System
Switch
EM. HEAT, HEAT, OFF, COOL
2
WIRING TERMINAL (UP TO 12)
MOUNTING HOLES (4)
Use when E and W2 are jumpered. Does not replace T841A1068. Not for systems with E to W jumper
Exact replacement for York model no. 2TH11703324
BACK OF DEVICE
Auto Fan
in EM.
HEAT
No
Yes
M2960A
®U.S. Registered Trademark Copyright © 1997 Honeywell Inc. • • All Rights Reserved
X-XX UL
69-0452-8
T841A HEATING-COOLING HEAT PUMP THERMOSTAT
OPERATION
The stages of heat drops.
Make
heat or cool.
There is about 1°F (0.6°C) between stages so the second stage (auxiliary heat) makes only when the first stage cannot handle the load. This 1°F is the
tial
.
The LED indicators on certain thermostat models light up when something specific happens within the system. When the green or amber LED lights, the auxiliary heat (second stage heat) is operating because the weather is so cold, the heat pump alone cannot handle the load. When the red EM. HEAT LED lights, the emergency heat is operating (usually electric strip heaters), because the homeowner has physically switched to the EM. HEAT position. See heating/cooling manufacturer instructions for specific meaning.
make
refers to the mercury switch initiating a call for
sequentially as the temperature
interstage differen-
RECYCLING NOTICE
This control contains mercury in a sealed tube. Do
not
place the 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 your old control in the trash.
Contact your local waste management authority for instructions regarding recycling and the proper disposal of this control, or any control containing mercury in a sealed tube.
INSTALLATION
When Installing this Product…
1. Read these instructions carefully. Failure to follow them could damage the product or 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 technician.
4. After installation is complete, check out product operation as provided in these instructions.
not
place
CAUTION
1. Disconnect power supply to prevent electrical shock or equipment damage.
2. To prevent interference with the thermostat linkage, keep wire length to a minimum and run wires as close as possible to the thermo­stat base.
3. Do not overtighten the thermostat captive mounting screws, because damage to the threads can result.
4. Do not short across coil terminals on the relay. This can burn out the thermostat heat anticipator.
5. Never install more than one wire per terminal unless a factory-supplied jumper with spade terminal is used.
Location
Locate the thermostat about 5 ft (1.5m) above the floor in an area with good air circulation at average room tempera­ture.
Do not mount the thermostat where it can be affected by: — drafts, or dead spots behind doors and in corners. — hot or cold air from ducts. — radiant heat from sun, appliances or fireplaces. — concealed pipes and chimneys. — unheated (uncooled) areas such as an outside wall
behind the thermostat.
This thermostat is a precision instrument and was carefully adjusted at the factory.
Handle it carefully.
Mounting and Wiring
CAUTION
Disconnect power supply before beginning installation. Can cause electrical shock or
equipment damage.
The T841A can be mounted directly to a wall or horizontal outlet box. Choose the method that best fits your installation.
In replacement applications, check the existing thermostat wires for cracked or frayed insulation. Replace wires in poor condition.
All wiring must comply with local codes and ordinances.
69-0452—8
2
T841A HEATING-COOLING HEAT PUMP THERMOSTAT
Grasp the thermostat cover at the top and bottom with one hand. Pull outward on the bottom edge of the cover until it snaps free of the thermostat base. Carefully remove and save the packing material surrounding the mercury switches.
1. Run the wiring (if necessary) to the location. If the
wiring is plastered into the wall, make a hole next to the cable and loosen the wires so that they can be pushed back into the wall later. Thread the wires through the hole in the packing material saved above. Connect the wires to the terminals on the back of the thermostat. See Fig. 2 through 5.
2. Set the second stage adjustable heat anticipator to
match the current draw of the primary heating control (see Heat Anticipator Setting section).
3. Push the excess wire back through the hole and
plug any opening with packing material to prevent drafts that may affect thermostat performance.
4. Use screws to loosely secure the thermostat to the
wall or outlet box through the two mounting holes in the middle of the device.
The sheetmetal screws included with the thermostat are designed for use in plaster walls that do not need anchors.
IMPORTANT
An incorrectly leveled thermostat causes inaccurate temperature control.
5. Level the thermostat using a spirit level or plumb
line. Tighten the two mounting screws at the middle of the device.
6. Install the two screws in the top mounting holes and
tighten.
7. Replace the thermostat cover.
H1
C1
H1 & C1 ANTICIPATOR
FALL
FAN SWITCH
AUTO
ON
H2 ANTICIPATOR
SYSTEM
H2
FALL
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
1
PROTECTION AS REQUIRED.
WHEN SYSTEM MONITOR IS CONNECTED TO L TERMINAL, EM. HT.
2
LED ALSO INDICATES COMPRESSOR MALFUNCTION.
X TERMINAL MUST BE CONNECTED FOR PROPER OPERATION.
3
Fig. 2. Internal schematic and typical wiring diagram for TRADELINE® T841A1308 with EM. HEAT and AUX. HEAT
LEDs. No fan control in EM. HEAT. Provides heat or cool changeover relay control.
SWITCH
EM. HEAT
HEAT
OFF
COOL
SETTINGS
Heat Anticipator Setting
The second stage heat anticipator is adjustable. Move the adjustable indicator to match the current draw of the second stage heating primary control, or the anticipator setting of the old thermostat. See Fig. 6.
Temperature Setting
Move the setpoint lever to the desired control point on the temperature scale.
SYSTEM Switch Setting
The SYSTEM switch positions control the system opera­tion as follows:
EM. HEAT: Emergency heat relay is energized. Cooling
system is off. Compressor is de-energized. Fan runs on call for heat if FAN switch is in the AUTO position. EM. HEAT LED is on.
HEAT: Heating system is automatically controlled by
the thermostat. Cooling system is off.
OFF: Both the heating and cooling systems are off. If
the fan is at the AUTO position, the cooling fan is also off.
COOL: Cooling system is automatically controlled by
the thermostat. Heating system is off.
FAN Switch Setting
AUTO: Fan operates in response to thermostat in both
heating and cooling.
ON: Fan operates continuously.
L1
1
M1099B
(HOT) L2
69-0452—8
AUX. HT. LED (GREEN)
EM. HT. LED (RED)
3
ODT 1
RTD 1
EHR 1
RTD 2
ODT 2
RTD 3
LACO
ERH 2
RD
CHANGEOVER RELAY (HEAT)
COMPRESSOR CONTACTOR
CHANGEOVER RELAY (COOL)
RTD 1
EM. HEAT RELAY
CHP
FAN RELAY
G
R
SYSTEM MONITOR
W2
E
L
B
2
X
3
Y
O
T841A HEATING-COOLING HEAT PUMP THERMOSTAT
L1 (HOT)
1
CHANGEOVER
CHANGEOVER RELAY (HEAT)
COMPRESSOR CONTACTOR
RELAY (COOL)
FAN RELAY
EM. HT. RELAY
AUX. HT. RELAY
HEAT RELAY 1
M1103E
O
H1
H2
1
2
3
4
Fig. 3. Internal schematic and typical wiring diagram for SUPER TRADELINE® T841A1316 with AUX. HEAT and
EM. HEAT LEDs. Provides heat or cool changeover relay control and automatic fan in EM. HEAT mode.
FALL
C1
H1 ANTICIPATOR
C1 ANTICIPATOR
FALL
H2 ANTICIPATOR
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
REMOVE W1-Y1 JUMPER WHEN HEAT RELAY 1 IS USED.
WHEN L TERMINAL IS CONNECTED TO SYSTEM MONITOR, EM. HEAT LED ALSO INDICATES COMPRESSOR MALFUNCTION.
X TERMINAL MUST BE CONNECTED FOR PROPER OPERATION.
FAN SWITCH
AUTO
ON
SYSTEM
SWITCH
EM. HT.
HEAT
OFF
COOL
EM. HT. LED (RED)
AUX. HT. LED (GREEN)
L
SYSTEM
3
MONITOR
G
R
E
4
X
W2
B
W1
2
JUMPER
Y1
L2
AUTO
SYSTEM SWITCH
3
EM. HT.
HEAT
COOL
ON FAN
SWITCH
OFF
EM. HT. LED (RED)
4
FALL
H1
C1
H1/C1 ANTICIPATOR
H2 ANTICIPATOR
FALL
H2
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
1
OVERLOAD PROTECTION AS REQUIRED.
2
B TERMINAL MUST BE CONNECTED FOR PROPER OPERATION.
3
AUTO FAN IN EM. HEAT.
Fig. 4. Internal schematic and typical wiring diagram for TRADELINE® T841A1498 and T841A1506
with EM. HEAT LED. Provides cooling changeover relay control.
69-0452—8
G
R
W
H
2
B
X
O
Y
FAN RELAY
HEAT RELAY
"H" RELAY
EM. HT. RELAY
CHANGEOVER RELAY (COOL)
COMPRESSOR CONTACTOR
M3171B
L1 (HOT)
L2
1
T841A HEATING-COOLING HEAT PUMP THERMOSTAT
AUX. HT. LED (GREEN)
EM. HT. LED (RED)
W3
G
R
W2
E
L
CHECK LED (RED)
B
X
Y
O
8
EM. HT.
HEAT
OFF
COOL
FAN SWITCH
AUTO
ON
SYSTEM SWITCH
2
H1
C1
FALL
H1/C1 ANTICIPATOR
H2
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
AUTO FAN IN EM. HEAT.
2
FALL
5
9
3
4
12
11
10
6
LACO
RTD 1
RD
ODT 1
EHR 1
ODT 2
FAN REALY
EM. HT. RELAY
SYSTEM MONITOR
HEAT CHANGE­OVER VALVE
COMPRESSOR CONTACTOR
COOL CHANGE­OVER VALVE
RDT 2
RTD 3EHR 2
RTD 1
1
L1 (HOT)
CHP
M6059C
L2
Fig. 5. Internal schematic and typical wiring diagram for TRADELINE® T841A1423 and T841A1464 (sold only in
Australia) with AUX. HEAT, EM. HEAT and CHECK LEDs. Provides heat or cool changeover relay control and
automatic fan in EM. HEAT mode.
.10
.12
.15
1.2
.8.6.4
.2
.3
LONGER
EM.HEAT HEAT OFF COOL
MOVE INDICATOR TO MATCH CURRENT RATING OF PRIMARY CONTROL
M2962B
Fig. 6. Second stage adjustable heat anticipator indicator.
5
69-0452—8
T841A HEATING-COOLING HEAT PUMP THERMOSTAT
CHECKOUT
Heating
Move the SYSTEM switch on the thermostat to HEAT and the FAN switch to AUTO. Move the setpoint lever to about 10°F (6°C) above the room temperature. Heating should start and the fan should run. Move the setpoint lever about 10°F (6°C) below the room temperature. Heating and fan should shut off.
NOTE: To prevent compressor short cycling, a minimum-
off timer may be included to prevent the com­pressor from starting for up to five minutes from when the thermostat last turned the compressor off, or from when the system first received power.
Cooling
CAUTION
Do not operate cooling if outdoor temperature is below 50°F (10°C). Refer to manufacturer recom­mendations.
Move the SYSTEM switch on the thermostat to COOL and the FAN switch to AUTO. Move the setpoint lever about 10°F (6°C) below the room temperature. Cooling and fan should start. Move the setpoint lever about 10°F (6°C) above the room temperature. Cooling and fan should shut off.
Fan
Move the SYSTEM switch to OFF, and the FAN switch to ON. The fan should run continuously. Move the FAN switch to AUTO. In this position, the fan operates in response to the thermostat in both heating and cooling.
Automation and Control Solutions
Honeywell International Inc. 1985 Douglas Drive North Golden Valley, MN 55422
69-0452—8 J.S. Rev. 5-97 www.honeywell.com/yourhome
69-0452—8
Honeywell Limited-Honeywell Limitée 35 Dynamic Drive Scarborough, Ontario M1V 4Z9
6
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