® AUTOMATED HVAC THE BEST IN INDOOR AIR COMFORT Communicating Thermostat System Installation Manual A PA R T O F T H E A P R I L A I R E® I N D O O R A I R C O M F O R T S Y S T E M
COMMUNICATING THERMOSTAT SYSTEM INSTALLATION MANUAL This manual will guide the installer through the installation, wiring and checkout of an Aprilaire Model 8870 Communicating Thermostat System. Instructions for the Aprilaire 8840 Series communicating thermostat system are found in a separate document (DP 10004345). A portion of the command set is found in Appendix 2 in this manual. For a complete command set with programming suggestions, see the programming manual (DP 10005756).
Step1 GET ALL THE COMPONENTS YOU WILL NEED COMPONENTS YOU WILL NEED… (see ILLUSTRATION 1) • One Aprilaire® Model 8870 Communicating Thermostat for each zone or single zone HVAC system • One Aprilaire Model 8818 Distribution Panel per eight (8) thermostats in the system • One Aprilaire Model 8811 Protocol Adapter per 32 thermostats or one per Model 8823 system controller • 4 to 8 conductor thermostat cable depending on equipment stages (18 – 20 gauge) • Category 5 communication wire (4-pair twisted cable) •
MODEL 8870 THERMOSTAT The Model 8870 Thermostat is field configurable to operate single and multi-stage separate heating and cooling equipment (such as furnace and air conditioner or roof top units), or single and multi-stage heat pump systems. A menu driven set up, using the message center display of the thermostat, can be used to configure many other features. Network communication is non-isolated, full duplex RS-485 (RS-422).
Step 3 RUN THE REQUIRED WIRES (SEE ILLUSTRATION 2) 3. Run Category-5, 4-pair twisted cable (8-conductor) from each thermostat to the Distribution Panel. 4. At the Distribution Panel, use a piece of tape to ✍ label the location of the thermostat on the cable as you go. 5. Run Category-5 wire from the Distribution Panel to the Protocol Adapter. If more than one Distribution Panel is used, run Category-5 wire between each panel. 6.
Step 4 LOCATE AND MOUNT THE AUTOMATION SYSTEM COMPONENTS 1. Thermostats and sensors are to be located according installation instructions provided with the units. The thermostat has four configuration dip switches on the circuit board that must be set according to the equipment the thermostat will be controlling. Sensors have six configuration dip switches that must be properly set. The installation manuals provided with the products detail how the switches are to be set.
CAT-5 WIRE DISTRIBUTION PANEL POWER RX TX RX TX RX TX DATA ENABLE DATA RS-485 RS-485 RS-232 CAT-5 WIRE ADDRESS RS-232 LOCATION RS-485 ADDRESS RS-485 Model 8811 Protocol Adapter Power 7.
Step 5 CONNECT THE CONTROL WIRES TO THE HVAC/ZONE SYSTEM AND THERMOSTATS DIAGRAM 1 – Typical Heating / Cool Wiring Schematic MULTI-STAGE FURNACE USE 18-20 GA. THERMOSTAT CABLE. NUMBER OF CONDUCTORS REQUIRED DEPENDS ON THE HVAC SYSTEM BEING CONTROLLED Y2 2ND STAGE COOL 2ND STAGE HEAT W2 1ST STAGE COOL 1ST STAGE HEAT Y1 W1 FAN RELAY G C 24 VAC 120 VAC R L1 L2 A qualified HVAC technician should perform this step to ensure proper termination. 1. Make sure the HVAC system power is off. 2.
COMMUNICATION SYSTEM WIRING DIAGRAM 3 shows all communication system wiring with terminations. Steps 6 through 8 provide additional detail for each wiring step. DIAGRAM 3 – System Communication Wiring Model 8811 PROTOCOL ADAPTER POWER RX TX RX TX RX TX DATA ENABLE DATA RS-485 RS-485 RS-232 2-WIRE TSTAT CABLE 7.
Step 6 CONNECT THE COMMUNICATION AND POWER WIRES TO THE DISTRIBUTION PANEL AND THERMOSTAT 1. MAKE SURE THAT ALL SWITCHES IN THE DISTRIBUTION PANEL ARE OFF! 2. Connect the communication wires. DIAGRAM 4 shows how each thermostat is to be wired to the distribution panel. • Use the wire colors shown in DIAGRAM 4 to help ensure proper, consistent connections. 3.
Step 7 CONNECT MULTIPLE DISTRIBUTION PANELS 1. MAKE SURE THAT ALL SWITCHES IN THE DISTRIBUTION PANEL ARE OFF! 2. If more than one Distribution Panel is used in the thermostat network, the communication lines must be daisy-chained together. • Use the wire colors shown in DIAGRAM 5 to help ensure proper, consistent connections.
Step 8 CONNECT PROTOCOL ADAPTER TO THE DISTRIBUTION PANEL AND HOST COMPUTER OR AUTOMATION SYSTEM 1. MAKE SURE THAT ALL SWITCHES IN THE DISTRIBUTION PANEL ARE OFF! 2. Use Category-5 wire to connect the main communication terminals on the Distribution Panel with the “Flying Leads” of the protocol adapter (see DIAGRAM 6). 3. Connect the RS-232 port of the protocol adapter to the computer or automation system. A 6 ft.
Step 9 PROVIDE POWER TO THE DISTRIBUTION PANEL 1. MAKE SURE THAT ALL SWITCHES IN THE DISTRIBUTION PANEL ARE OFF! 2. Use a 2-wire thermostat cable to connect the load terminals of the Model 8027 Plug-in Transformer to the 24V AC terminals of the Distribution Panel (see DIAGRAM 3). 3. Plug-in the transformer. 4. NO LEDs ON THE DISTRIBUTION PANEL SHOULD BE ON. Step 10 TURN ON POWER TO ALL HVAC EQUIPMENT AND TO THE THERMOSTATS A+ A- B+ B- R R C C B- B+ A- A+ FUSE C C R A+ A- B+ B- R B- B+ A- A+ 4.
Step 12 ADDRESS THE THERMOSTATS AND SET HIGHEST ADDRESS IMPORTANT! THESE STEPS MUST BE DONE AT EACH THERMOSTAT FOR COMMUNICATION TO WORK PROPERLY. 1. Press the Mode and Enter buttons simultaneously through the thermostat. It may take a couple of tries to get them pressed together. This will enter the Thermostat Set Up Menu.
Step 13 SETUP COMPUTER FOR COMMUNICATION SYSTEM CHECKOUT 1. Connect the Protocol Adapter RS-232 output to a computer with Windows ’95, ’98, Windows 2000 or Windows NT. This may already have been done in Step 7. 2. Turn on the computer. 3. From the Start menu, select PROGRAMS➾ ACCESSORIES➾ COMMUNICATION➾ HYPERTERMINAL (see ILLUSTRATION 6). HyperTerminal is a terminal emulator program provided with Windows that will be used to test the communication system.
6. This will bring up a Connect to dialog box. From the pull down next to “Connect using:”, select the Com port to which the Protocol Adapter is connected (see ILLUSTRATION 8). Start with Com port 1 (or the next lowest available number) if you are unsure which one to use. Click OK. ILLUSTRATION 8 – Select Com Port 7. A COM1 Properties dialog box should appear.
8. From the File pull-down menu, select Properties. This will bring up a Properties dialog box. 9. Select the Settings tab. Make the following selections (see ILLUSTRATION 10): Terminal keys Ctrl+H Emulation: Auto Detect Telnet terminal: ANSI Backscroll buffer lines: 500 ILLUSTRATION 11 – ASCII Setup ILLUSTRATION 10 – Terminal Settings 10.Then select the ASCII Setup button. This will bring up an ASCII Setup dialog box.
Step 14 CHECK-OUT COMMUNICATIONS TO THE THERMOSTAT NETWORK 1. At the computer type SN? (it does not matter if it is small or capital letters) then press Enter. You should get no response because none of the communication switches to the thermostats have been turned on yet. 2. Go to the Distribution Panel and turn on the communication switches for the thermostat with address #1 (see ILLUSTRATION 12). 3. Type SN? and press Enter. The computer should respond SN1.
Appendix 1 SPECIAL CONSIDERATIONS FOR INSTALLING THE MODEL 8870 WITH THE 8840 SERIES COMMUNICATING THERMOSTAT If adding a Model 8870 thermostat to a system using 8840 series thermostats (8844, 8846, 8847 or 8848), you must change the power supply installation, modify the addressing method and remove terminating resistors from the Model 8811 protocol adapter. 1. A separate power supply is required for Model 8870 thermostats and 8840 series thermostats. This requires different wiring.
DIAGRAM 8 – Adding an 8840 Series Thermostat MODEL 8870 THERMOSTAT C R RSR RSC RSB RSA REF BRN GRN CAUTION! TURN ALL DISTRIBUTION PANEL SWITCHES OFF BEFORE DOING ANY WIRING.
Appendix 2 APRILAIRE COMMAND SET SN# [Command] [? or =] [Value (use with = only) ] Enter A full command set and detailed explanation of the EXCEPTION: The command SN? or SN0? will respond with command set is available for those who want to write their all connected thermostats returning their address. own software. Contact Research Products Corporation at 888-782-8638 to request a copy of DP 10005756. Upper or lower case letters may be used for all commands.
MODEL 8870 BASIC COMMAND SET COMMAND DESCRIPTION Communication Control Commands CR Command Response Control C1 Change of State (COS) – HVAC relays C2 COS – Temperature C3 COS – Remote Temperature C5 COS – Set Points C6 COS – Network Override C7 COS – Mode C8 COS – Fan HOLD User Hold Status NAME Location Name ID Report Model No. and software rev.
21 CAT-5 WIRE DISTRIBUTION PANEL POWER RX TX RX TX RX TX DATA ENABLE DATA RS-485 RS-485 RS-232 CAT-5 WIRE ADDRESS LOCATION TO DISTRIBUTION PANEL Power 7.
1015 E. WASHINGTON AVE. • MADISON, WI 53703 • PHONE: 888/782-8638 • FAX: 608/257-4357 • www.aprilaire.com DP 10005754 1.5.4.
