Honeywell Q674L Installation Instructions Manual
Thermostats with subbases
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Also See for Q674L:
- Installation instructions manual (13 pages) ,
- Installation instructions manual (8 pages) ,
- Installation instructions manual (6 pages)
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T874R Thermostats and Q674L Subbases
APPLICATION
The T874R Thermostat and Q674L Subbase provide 24 to 30 Vac control of 2-stage heating and 1-stage cool-ing heat
pump systems with manual changeover. Q674L Subbase provides EM.HT.-HEAT-OFF-COOL system switching and
AUTO-ON fan switching. See Table 1 for specific T874R/Q674L combinations.
Thermostat/
Thermostat/
Subbase
Subbase
Package
Numbers
Y594R1243
T874R1152/
Q674L1207
Y594R1300
T874R1475/
Q674L1520
Y594R1425
T874R1616/
Q674L1587
Y594R1615
T874R1822/
Q674L1710
Y594R1664
T874R1871/
Q674L1736
Y594R1672
T874R1889/
Q674L1736
Y594R1698 b
T874R1905/
Q674L1777
Y594R1706 b
T874R1913/
Q674L1777
Y594R1763
T874R1954/
Q674L1827
Y594R1797
T874R1988/
Q674L1868
a
EM.HT. LED also shows compressor malfunction.
b
Premier White® color.
®U.S. Registered Trademark
Copyright © 1997 Honeywell Inc. •
Installation Instructions for the Trained Service Technician.
Table 1. Thermostat/Subbase Specifications.
Model
LED
Indication
AUX.HT.,
EM. HT.
AUX.HT.,
EM. HT. a
AUX.HT.,
EM. HT.,
CHECK
AUX.HT.,
EM. HT.,
CHECK
EM. HT.
EM. HT.
EM. HT.
EM. HT.
AUX.HT.,
EM. HT. a
AUX.HT.,
EM.HT.
• All Rights Reserved
INSTALLATION INSTRUCTIONS
Changeover
TRADELINE ® ; adjustable stage 2
Manual Cool
heat anticipation. Fixed anticipation
in stage 1. Auto fan in EM.HT.
TRADELINE ® ; fixed heat
Manual Heat
or Cool
anticipation. Auto fan in EM.HT.
SUPER TRADELINE ® ; fixed heat
Manual Heat
or Cool
anticipation. Factory installed jumper
across W1 and Y1. Auto fan in
EM.HT.
TRADELINE ® ; fixed heat
Manual Heat
or Cool
anticipation. Auto fan in EM.HT.
TRADELINE ® ; exact replacement
Manual Cool
for York model no. 2TH11702224.
TRADELINE ® ; exact replacement
Manual Cool
for York model nos. 2TH11702324
and 6TH11702224.
TRADELINE ® ; exact replacement
Manual Cool
for York model nos. 2TH11702324
and 6TH11702224. Includes
C815A1054 Outdoor Thermistor.
TRADELINE ® ; exact replacement
Manual Cool
for York model no. 2TH11702224.
Manual Cool
Requires C815A Outdoor Thermister
for outdoor reset. Fixed stage 1 heat
anticipation. No heat anticipation in
stage 2 heat. Auto fan in EM.HT.
Replaces Y594R1136.
TRADELINE ®
Manual Heat
or Cool
X-XX UL
Comments
69-0392-9
See
Fig.
6
7
8
10
9
11
11
9
5
12
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Table of Contents
Related Manuals for Honeywell Q674L
Summary of Contents for Honeywell Q674L
- Page 1 Installation Instructions for the Trained Service Technician. APPLICATION The T874R Thermostat and Q674L Subbase provide 24 to 30 Vac control of 2-stage heating and 1-stage cool-ing heat pump systems with manual changeover. Q674L Subbase provides EM.HT.-HEAT-OFF-COOL system switching and AUTO-ON fan switching. See Table 1 for specific T874R/Q674L combinations.
- Page 2 T874R THERMOSTATS AND Q674L SUBBASES OPERATION On a 2-heat thermostat, the two stages of heat sequentially as the temperature drops. mercury switch initiating a call for heat or cool. There is about 1° F (0.6° C) between stages so the sec- ond stage makes only when the first stage can not handle the load.
- Page 3 See Fig. 3. IMPORTANT Use 18 gauge, color-coded thermostat cable for proper wiring. T874R THERMOSTATS AND Q674L SUBBASES 4. Secure the cover plate (if used) and subbase with COVER 5. Level the subbase by using a spirit level. Firmly...
- Page 4 T874R THERMOSTATS AND Q674L SUBBASES THERMOSTAT FALL FALL POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. FIELD REMOVABLE JUMPER. Fig. 5. Internal schematic and typical wiring diagram for Y594R1763 (T874R1954/Q674L1827). Replaces GE AY28X078, AY28X139; Trane Baystat 139, Baystat 239 and Baystat 240;...
- Page 5 Fig. 8. Internal schematic and typical wiring diagram for Y594R1425 (T874R1616/Q674L1587). SUPER ® TRADELINE ; universal model for heat, cool, or first stage heating changeover systems. CHECK LED has isolated terminals for use in all systems. T874R THERMOSTATS AND Q674L SUBBASES SUBBASE RTD 1 SWITCH AUTO EM.
- Page 6 T874R THERMOSTATS AND Q674L SUBBASES THERMOSTAT FALL H1/C1 ANTICIPATOR FALL ANTICIPATOR RESET HEATER POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. Fig. 9. Internal schematic and typical wiring diagram for Y594R1664 (T874R1871/Q674L1736) and Y594R1706 (T874R1913/Q674L1777). Exact replacement for York model no. 2TH11702224.
- Page 7 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. TERMINAL LABELED C/X ON SOME MODELS. W3 TERMINAL AVAILABLE ON SOME MODELS ONLY. Fig. 12. Internal schematic and typical wiring diagram for Y594R1797 (T874R1988/Q674L1868). T874R THERMOSTATS AND Q674L SUBBASES SUBBASE FAN SWITCH AUTO...
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Page 8: Heat Anticipator Setting
T874R THERMOSTATS AND Q674L SUBBASES Mounting the Thermostat 1. Remove the thermostat cover by pulling the bottom edge of the cover away from the base until it snaps free from the cover clip. NOTE: The cover is hinged at the top and can be removed by pulling out at the bottom. -
Page 9: Emergency Heat
ON. The fan should run continuously. When the fan switch is in the AUTO position, fan operation is con- trolled by the heating or cooling system. T874R THERMOSTATS AND Q674L SUBBASES CALIBRATION Thermostat T874 Thermostats are accurately calibrated at the factory. - Page 10 T874R THERMOSTATS AND Q674L SUBBASES 69-0392—9...
- Page 11 T874R THERMOSTATS AND Q674L SUBBASES 69-0392—9...
- Page 12 T874R THERMOSTATS AND Q674L SUBBASES Automation and Control Solutions Honeywell International Inc. Honeywell Limited—Honeywell Limitée 1985 Douglas Drive North 35 Dynamic Drive Golden Valley, MN 55422 Scarborough, Ontario M1V 4Z9 69-0392—9 G.H. Rev. 10-97 69-0392—9 www.honeywell.com/yourhome...