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T8511G,R Microelectronic
Heat Pump Thermostats
INSTALLATION INSTRUCTIONS
APPLICATION
The T8511 Microelectronic Heat Pump Thermostat provides electronic control of 24 Vac two-stage heating and one-stage
cooling heat pump systems. Refer to Table 1 for a general description of the thermostat. All T8511 Thermostats require a
common wire to supply power.
Table 1. Description of T8511 Thermostats.
Fan
T8511 Changeover System Selection Selection Comments
G Automatic Em. Heat-Heat-Off-Auto-Cool On-Auto
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS YES NO NO 5 FEET [1.5 METERS] NO M10106 Fig. 1. Typical location of thermostat. WALL 4. Position the wallplate over the holes, pulling wires through the wiring opening. WIRES 5. Loosely insert the mounting screws into the holes. THROUGH WALL 6. Tighten mounting screws. WIRING WALL All wiring must comply with local electrical codes and ANCHORS (2) ordinances. Refer to Fig. 3 through 5 for typical hookups. A letter code is located near each terminal f
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS THERMOSTAT THERMOSTAT OT OT W1 O/B G Y1 C E W2 L R OT OT B OG Y C L R 2 2 OUTDOOR OUTDOOR TEMPERATURE TEMPERATURE SENSOR SENSOR EM. HEAT RELAY HEAT EQUIPMENT RELAY 2 COMPRESSOR COMPRESSOR MONITOR CONTACTOR CONTACTOR EQUIPMENT MONITOR FAN FAN RELAY RELAY COOL COOL/HEAT CHANGEOVER CHANGEOVER VALVE VALVE HEAT HEAT CHANGEOVER 1 RELAY 1 1 VALVE L1 L1 (HOT) (HOT) L2 L2 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS A. ENGAGE TABS AT TOP OF THERMOSTAT AND WALLPLATE. Heat: The thermostat controls the heating. Off: Both the heating and cooling are off. Cool: The thermostat controls the cooling. Auto: The thermostat automatically changes between heating and cooling operation, depending on the indoor temperature. Fan settings control the system fan as follows: On: Fan operates continuously. Auto: Equipment controls fan. B. PRESS LOWER EDGE OF CASE TO LATCH. The s
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS INSTALLER SETUP Em Ht Temporary Setting Remote Aux Ht Room NOTE: For most applications, the thermostat factory- settings do not need to be changed. Review the %Humid factory settings in Table 2 and if no changes are Outdoor Repl necessary, go to the Installer System-Test Wait Heat Cool Batt section. System Fan Em HeatOffCool Auto Only OnAuto The Installer Setup is used to customize the thermostat to specific systems. Some of the options include temp
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS Table 2. Thermostat Installer Setup Options (Continued). Installer Setup Other Choices Number Factory-Setting (Press ▲ or ▼ key to change) (Press i key Actual Select to change) Display Description Display Description Setting Extended fan 19 00 No extended fan 01 Fan operation is extended operation in operation after the call 90 seconds after the call for heating for heat ends heat ends Extended fan 20 00 No extended fan 01 Fan operati
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS NOTE: Press and hold the increase ▲ and decrease ▼ INSTALLER SYSTEM-TEST keys for three seconds to exit the system-test. The system-test times out after five minutes Use the Installer System-Test to check the thermostat without any key presses. configurations and operation. Refer to Table 3 for a list of the available system-tests. Table 3. Tests Available in the Installer System-Test. Test To start the system-test: Number System-Test Description N
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS Table 4. Installer System-Test Options. (Continued) Key To Test Press Number Description Fan Equipment System-Test (T8511G only) i 40 Change from cooling to fan equipment system-test. ▲ 41 Fan comes on. ▼ 40 Fan turns off. T8511G System Key or T8511R System Switch Operation System-Test IMPORTANT Test numbers will only be displayed when the system is configured for the selected function. EXAMPLE: Numbers 60, 61 and 62 are the only numbers tha
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS 5. Press the increase ▲ key again to display the CHECKOUT EEPROM identification code. (Example: 222 = EEPROM ID 222) Outdoor Temperature Sensor (Where Applicable) Allow the outdoor temperature sensor to soak in the outdoor air for a minimum of five minutes before taking a reading. With an accurate thermometer (±1°F [±0.5°C]), measure the temperature at the sensor location, allowing time for the thermometer to stabilize before reading. Match the ther
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS TROUBLESHOOTING GUIDE (Continued) Symptom Possible Cause Action Heating will not Thermostat minimum off time is Wait up to five minutes for the system to respond. come on. activated. (Continued) System selection is not set to Set system selection to Heat. Heat. O/B terminal configured Check Installer Setup mode number 29 and reconfigure a incorrectly . correctly. a O or B terminal miswired . Check system description to determine whether changeover s
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS 11 69-0927—4
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T8511G,R MICROELECTRONIC HEAT PUMP THERMOSTATS Automation and Control Solutions Honeywell International Inc. Honeywell Limited-Honeywell Limitée 1985 Douglas Drive North 35 Dynamic Drive Golden Valley, MN 55422 Scarorough, Ontario M1V 4Z9 69-0927—4 G.H. Rev 69-0927—4 . 04-04 www.honeywell.com/yourhome 12
