PG 1 Install Guide CT80 Caution • The thermostat is a precise instrument, handle with care. • Turn off electricity to the HVAC system before installing or servicing thermostat or any part of the system. • Do not turn electricity back on until work is completed. • Do not short (jumper) across electric terminals at the control on the furnace or air conditioner to test the system. This may damage the thermostat. • All wiring must conform to local codes and ordinances.
PG TOOLS You will need a small Phillips screwdriver and a drill with 3/16-in. (4.8mm) bit for wall mounts. LOCATION Replacement installations - mount the CT80 in place of the thermostat. You must have a “C” wire or other 24VAC power available at the CT80 location. A new location will require moving your wiring. New installations and for relocating the CT80 - follow the guidelines listed below: • Locate the thermostat on an inside wall, about 5 ft. (1.5m) above the floor, and in a room that is used often.
REMOVE OLD UNIT Switch OFF electricity to the furnace and air conditioner; then follow these steps. • Remove cover from old thermostat. Most are snap-on types and simply pull off. Some have locking screws on the side or front. These must be loosened. DO NOT remove wires. Note the letters printed near the terminals. Attach labels (enclosed) to each wire for identification. Caution • Label the wires one at a time. You must label all the wires before you proceed.
PG What wires do you have? Make sure your wires are labeled. This may require you to find the ‘other end’ connection for each wire on your heating or air conditioning equipment and read the label there. Refer to the Wire Reference page at end of install section for better understanding of wire labels from different HVAC system makers. IMPORTANT: The CT80 requires constant 24VAC power from the HVAC system’s “C wire”.
Find the step-by-step diagram for your system W C WRG From HVAC R W C Go To page 14 C G Go To page 14 B W 5 Wire Heat/Cool Y R Go To page 15 or O YR G Heat Pump w/o Aux Heat From HVAC From HVAC C G WIRES Multi-stage Cool Multi-stage Heat WIRES WIRES Wn Yn R G From HVAC 4 Wire Heat R WYRG From HVAC WIRES 3 Wire Heat WIRES W R WIRES WIRES From HVAC • Select the reference page with your wiring diagram and set-up W Y RH RC G information below.
PG • “Fan out” wires as illustrated with CT80 below the wall opening. As in the example: fan out the wires so that the C wire is above the C terminal, the W above the W. This allows the CT80 to fit snug to the wall. from HEAT/COOL system C W Y R G Caution Do not allow wires to touch each other or parts on thermostat. • Wires will position behind the CT80 and up over the terminal area. • Do not bunch wires behind the CT80. Feed any slack back into the wall opening.
Wall Mount the CT80 to Wall 1. Hold the CT80 against the wall, with the wires coming over the CT80 top; above terminal block. The CT80 will cover the hole in the wall. 2. Position CT80 for best appearance. 3. Attach the CT80 to the wall with the screws provided. 4. If you are mounting the CT80 to sheet rock or if you are using the old mounting holes, use the plastic anchors provided. 5. Mark first and drill a 3/16-in.(4.8mm) hole for the insert at each from screw location, then mount the unit.
PG Turn ON Power With all the wires connected (including the C wire), it is time to turn the AC power back on. Do this at the breaker you used to switch it off. The CT80 will power-up in the control OFF mode. Your CT80 is not configured to operate your HVAC system yet. You must now use the menu driven HVAC SET-UP function. HVAC setup IMPORTANT: Make sure the CT80 is powered up and is in the OFF mode before set-up.
Is your heat GAS/OIL or ELECTRIC? Is your system multi-stage? No 2 Stages 3 Stages Thank you, your thermostat is configured to control your HEATing. Configure COOL? How many stages of A/C do you have? 1 stage 2 stage Thank you, your thermostat is configured to control your COOLing.
PG 4. Select the appropriate number of stages for your heating system (from 1 to 3) by touching the number of STAGES (in brackets) to highlight, and using the +/- buttons to increase or decrease. 5. Touch the appropriate FAN CONTROL setting. Select HVAC if your heating system controls the fan (appropriate for most gas, oil, propane and similar furnaces). Select TSTAT if you want the thermostat to control the fan (for most electric heating systems). 6.
5. If you have AUXILIARY heat, touch the number of stages (default is [NONE] ) use the +/buttons to select 1-3 stages. (NOTE: The CT80 controls a maximum of 5 stages total between pump and AUX.) 6. (If you have AUX) Select the type of auxiliary heat that you have - Electric or Gas-Oil. NOTE: Most heat pump systems have electric heat strips for auxiliary heat. 7. Fan Control is set by the CT80 (tstat) for heat pumps. 8. Press HOME button to return to the Home Fan screen.
PG Test Installation cont. To check HEAT mode: 1. Press the mode control and select HEAT. 2. Press the + button to raise the target temp to 90 F. Allow the system 2 minutes to respond. 3. Verify that heat is blowing from the system. o 4. Return mode control to OFF (leave OFF for 4 minutes before checking COOL). To check COOL mode (do not operate AC if outside temp is below 65oF) : 1. Press the mode control and select COOL. 2. Press the blue - button to lower the cool target temperature to 50oF.
STATEMENT OF USE - This thermostat can be used with all 24VAC and millivolt (24VAC external power) heating and cooling systems. It cannot be used with line voltage systems. This thermostat is digital and your desired heat or cool temperatures can easily be set on the large touch screen with the +/- buttons. A minimum 4 minute off time protects heating and cooling compressors from damage.
PG Step-by-step wiring diagrams WIRES 3 Wire Heat GAS MILLIVOLT or 24VAC system STEP 1 - Connect the R (or RH) wire to the RH terminal. HVAC SYSTEM This connects the heat power. W R C STEP 2 - Connect the W wire to the W terminal. POWER This connects the heat. STEP 3 - Connect the C wire to the C terminal. Your heater is now connected to the CT80.
HVAC SYSTEM WIRES C W WYRG Y R G POWER 5 Wire Heat/Cool STEP 1 - Connect the W wire to the W terminal. This connects the heat. C H B O W W2 W3 Y Y2 RH RC G A DH EX STEP 2 - Connect the Y wire to the Y terminal. THERMOSTAT TERMINALS This connects the cooling compressor. STEP 3 - Connect the R (or RH) wire to the RH terminal. This connects the power. STEP 4 - Connect the G wire to the G terminal on the thermostat. This connects the fan. STEP 5 - Connect the C wire to the C terminal.
PG 16 Wn Yn R G Multi-stage Heat and Multi-stage Cool The CT80 can handle up to 3 stages of HEAT and 2 stages of COOL. HVAC SYSTEM STEP 1 - Connect the W, W2 and W3 wires to the W terminals. This C W W2 W3 Y Y2 R G POWER connects the stages of HEAT. STEP 2 - Connect the Y and Y2 wires to the Y terminals. This connects the stages of COOL. C H B O W W2 W3 Y Y2 RH RC G A DH EX STEP 3 - STEP 5 - Connect the R (or RH) wire to the RH THERMOSTAT TERMINALS terminal. This connects the power.
O or B AUXn Yn R G Multi-stage Heat Pump with Multi-stage Aux Heat The CT80 can handle up to 2 stages of Pump compression and 3 stages of AUX heat. STEP 1 - Connect O wire to the O terminal or B wire to the B terminal. This connects the change-over valve. If you have both O and B - connect only the O wire to the O terminal and DO NOT connect B to B terminal (see wire reference under Trane for B wire terminal).
PG Humidifier - To use the CT80 internal humidistat to control an external humidifier unit, connect it as shown. Connect the H terminal to the control leg of the humidifier relay. This allows H to turn the humidifier ON and Off. DeHumidifier - To use the CT80 internal humidistat to control an external dehumidifier unit, connect it as shown. Connect the DH terminal to the control leg of the dehumidifier relay. This allows DH to turn the dehumidifier ON and OFF.
Wire Reference Table Possible Wires R or V or VR RH or 4 RC W W2 W3 Y Y2 G or F C or X H DH EX B O B and O E L T What They Control RH and RC Single power for HEAT and COOL RH Power for HEAT (RH not connected to RC with switch in UP position) RC Power for COOL (RH not connected to RC with switch in UP position) W Heat control - Normal 1st stage heat or heat pump aux 1st stage W2 Normal 2nd stage heat or heat pump aux 2nd stage W
PG Wire Ref Cont.
APPENDIX 1 : Multi-staged HVAC theory of operation Staging for 2 stage normal Cool and 2 stage heat pump Cool Target Temperature Maintenance in COOL - If the room temperature is within the target temperature plus the “2nd stg on at” setting, the 1st stage of cool will turn on. If the target temperature is not reached within 15 minutes, the 2nd stage of cool will turn on with the 1st stage to the target temperature.
PG Staging for Heat Pump with 2 stages of compression (no auxiliary) Target Temperature Maintenance - If the room temperature is within the target temperature minus the “2nd stg on at” setting, the 1st stage heat pump will turn on. If the target temperature is not reached within 15 minutes, the 2nd stage of heat pump will turn on with the 1st stage to target.
APPENDIX 2 : FRESH AIR install and operation To use the FRESH AIR option; your system needs to have a fresh air baffle or an air to air exchanger. This unit needs to be in the closed/off position (outside air is blocked) when not energized (normally closed). Fresh Air baffle/ air to air exchanger installation - Connect one end of the wire to the HVAC’s C terminal and connect the other end to EX terminal on the thermostat. When Fresh Air is requested, the thermostat energizes EX (connects EX to RH).
