GE CC-SCSTAT - Manual

SmartCommand Thermostat Installation Manual 2 Product overview The SmartCommand thermostat (model CC-SCSTAT) provides typical thermostat functions as well as the capability to send and receive information via serial communications. This capability allows the thermostat’s setpoint, mode, and fan oper...

SmartCommand Thermostat Installation Manual 4 Thermostat control screen The Thermostat control screen ( Figure 2 ) is the default display screen normally displayed on the WDU. F igure 2. Thermostat control screen Temperature display The WDU will normally display the current temperature from the inte...

5 Up and down buttons The Up and Down buttons adjust the setpoint temperature. Press Up to increase the setpoint value by one degree and press Down to decrease the setpoint one degree. Pressing and holding a button down will cause the setpoint to continuously change until the button is released. The...

SmartCommand Thermostat Installation Manual 6 Run/Hold button The Run/Hold button controls the automatic schedule operation. In hold mode, the current temperature is maintained until changed by manual or remote network command. In the run mode, the schedule loaded into the thermostat is activated an...

7 Main menu screen The thermostat has a menu tree that can be accessed by pressing the Menu button on the main Thermostat control screen. Various configurations of the unit can have different screen contents. The first screen that will display is the Main menu screen ( Figure 3 ). This is a list of ...

9 Schedule setup screen The Schedule setup screen allows you to review and set the setback schedule for the thermostat. The thermostat has a 4 by 7 schedule. Four times a day can be selected for heating and cooling setpoints. Each day of the week can have a different schedule. Groups of days can be ...

SmartCommand Thermostat Installation Manual 10 Heat and cool schedule screen When you select the Heat and cool schedule menu item, the Heat and cool schedule screen ( Figure 6 ) opens and the schedule for the current day will be displayed. Use the scroll buttons to highlight the data to be modified....

SmartCommand Thermostat Installation Manual 12 User settings screen The User settings screen ( Figure 8 ) allows you to set or change various user options of the thermostat such as the clock, minimized screen timeout, Fahrenheit/Centigrade mode, sensor calibration, and backlight settings. F igure 8....

13 Set clock screen The Set clock screen ( Figure 9 ) is a sub screen of the User settings screen. The Set clock screen allows you to set the thermostat’s internal clock. To set the time and day, do the following: 1. Move the cursor with the navigation arrows until the data you want to change is hig...

SmartCommand Thermostat Installation Manual 14 Sensor calibration screen The Sensor calibration screen ( Figure 10 ) is a sub screen of the User settings screen on page 12. The Sensor calibration screen allows you to change the temperature calibration for the internal and any external remote tempera...

15 Backlight display screen The Backlight display screen ( Figure 11 ) is a sub screen of the User settings screen. The Backlight display screen allows you to set the backlight on and off brightness levels and contrast. F igure 11. Backlight display screen Screen options include: Backlight timeout. ...

SmartCommand Thermostat Installation Manual 16 Thermostat information screen The Thermostat information screen ( Figure 12 ) displays the current configuration of the thermostat wall display unit and the HVAC control unit. This information is useful for quick check of firmware versions and HVAC syst...

17 Installer settings screen The Installer settings screen is a hidden screen designed for installer use only. Do not change any settings in this screen unless you are a qualified service technician. Changing these settings will affect the operation of the heating/cooling system. To enter this scree...

SmartCommand Thermostat Installation Manual 18 Screen options include: Display lock: Y or N (default N). Use this setting to lock or unlock the thermostat wall display unit buttons. When the buttons are locked (Y), you can still access the Menu screen, but you will not be allowed to select any menu ...

19 Heating delta stage 3 on: 1 to 8 degrees (default 5). Set the delta from setpoint that stage 3 heating starts. Stage 3 turns off at setpoint. Cooling delta stage 1 on: 1 to 8 degrees (default 1). Set the delta from setpoint that stage 1 cooling starts. Stage 1 turns off at setpoint. Cooling delta...

SmartCommand Thermostat Installation Manual 20 Installation overview Before you remove an existing thermostat and install the SmartCommand thermostat, follow these guidelines: • Record existing wiring information. • Do the bench test. • Check WDU wiring before applying power to the control unit. • B...

21 Freeze protection In cold climates that require the heating system to be used for building freeze protection, a mechanical backup freeze protection device must be installed on the heating system. This can be a simple mechanical heating thermostat or a preset thermoswitch installed in the heated a...

SmartCommand Thermostat Installation Manual 22 Wall display unit installation Choose a location for the wall display unit (WDU) that best represents the temperature of the area to be controlled. Avoid locations that are subject to drafts or areas with direct sunlight exposure. Mounting To mount the ...

23 Control unit installation Install the control unit in a protected, convenient, indoor location near the HVAC system or in a service accessible area such as an equipment closet or garage. Mount the control unit in a vertical position on a wall or sturdy structural member. If you mount the control ...

SmartCommand Thermostat Installation Manual 24 HVAC system wiring Wiring will differ depending on if your system is a standard gas or electric system or if your system is a heat pump system. Standard HVAC system wiring Figure 18 shows the wiring diagram for a standard gas or electric HVAC system. Wi...

25 For standard HVAC systems, follow these guidelines: Single-stage systems. Use W1 for heating stage 1, and Y1 for cooling stage 1. Two-stage heating systems. Use W1 for stage 1, and W2 for stage 2 heating. Two-stage cooling systems. Use Y1 for stage 1 and Y2 for stage 2 cooling. HVAC system 24 VAC...

SmartCommand Thermostat Installation Manual 26 Heat pump HVAC system wiring Figure 19 shows the wiring diagram for a heat pump HVAC system. Wire colors are typical thermostat color codes. Note: Do not cut JP1 for heat pump systems. RC and RH are common for heat pumps. F igure 19. Heat pump HVAC syst...

27 For heat pump HVAC systems, follow these guidelines: Single-stage compressor systems. Use Y1 for stage 1 heating/cooling, and W1 for stage 2 heating (heat strips). Two-stage compressor systems. Use Y1 for stage 1, Y2 for stage 2 heating/cooling, and W1 for stage 3 heating (heat strips). DIP switc...

SmartCommand Thermostat Installation Manual 28 Control unit connection The control unit requires 24 VAC power from the HVAC system it is controlling. Connect the 24 VAC Common (blue wire/terminal) and 24 VAC R (red wire/terminal) from the HVAC system to the control unit’s HVAC system terminal block ...

29 Serial communication Serial communication includes: • RS485 com port • RS485 address • RS485 protocol • Thermostat network commands RS485 com port The thermostat has a RS485 serial com port. This is a two-wire (plus ground), half-duplex communication network. Typically, the thermostat will be use...

SmartCommand Thermostat Installation Manual 30 RS485 protocol The thermostat has a robust serial protocol. It is based on a simple ASCII message format as described in the Serial Communications Protocol manual, DCN: 150-00225. Note: Not all of the commands/variables defined in the protocol document ...

31 System checklist We strongly recommend that you hook-up and run a simple bench test before installing the thermostat. Not only will this save you time in system checkout, but will also make you familiar with the thermostat’s operation. Thermostat bench test To bench test the thermostat, do the fo...

SmartCommand Thermostat Installation Manual 32 Serial communication test Connect the thermostat to a PC via an RS232/485 converter to a PC serial com port. Note: Any RS232 to RS485 adapter used with SmartCommand serial thermostats must have automatic send data control. To use Windows HyperTerminal, ...

33 HVAC system testing If you have difficulty with the HVAC system operation, you can do the following test to verify the HVAC system is operational. Thermostats, like the SmartCommand thermostat, are just switches to the HVAC system as shown in the Figure 20 . This is a simplified example of a ther...

SmartCommand Thermostat Installation Manual 34 Standard HVAC system quick test You can do a quick test of the HVAC system by shorting across the appropriate terminals on the HVAC system’s thermostat connector. Use a short 6-in. wire to connect across the terminals shown in Table 1 . Heat pump system...

35 Control unit wiring Figure 21 shows the control unit wired to a wall display unit and the HVAC system. Wire colors are typical thermostat wiring colors. The fuse is a mini ATO 2 amp. Note: For heat pump HVAC systems, the orange wire (O) is the changeover valve. F igure 21. Control unit wiring HVA...

SmartCommand Thermostat Installation Manual 36 DIP switch SW1 settings White indicates a switch is in the On position. Set the DIP switches as follows: SW1-S1. HVAC system type selection. Standard or heat pump. Set S1 to Off (STD) for gas/electric systems (default setting).Set S1 to On (HP) for heat...

37 Serial network command and variable list Refer to the Serial Communications Protocol Manual 150-00225 for format details. Network commands Table 3 shows the network commands and a description of each command. Table 3. Network commands Command Description BF Set setback flag CFM Set F or C tempera...

SmartCommand Thermostat Installation Manual 38 Network variables Table 4 shows the network variables for use with the system variable, SVx command. The system type, fan type, and changeover type variables are determined by the controller DIP switch SW1 setting. They can be viewed by the system varia...

39 Contacting technical support For assistance installing, operating, maintaining, and troubleshooting this product, refer to this document and any other documentation provided. If you still have questions, you may contact technical support during normal business hours (Monday through Friday, exclud...