This solution consists of two pieces:
- The TB-100, which is a Z-Wave communicating digital temperature sensor and control panel. It does not contain any on-board relays, and operates on battery power (4 x CR-123). It communicates wirelessly with the RPTAC-5 to control the HVAC unit.
- The RPTAC-5, which is a remote HVAC controller, connects directly to the HVAC unit via 24VAC connections. It listens for wireless commands from the TB-100 and engages the HVAC unit’s heating, cooling, and fan modes accordingly. This device is typically installed directly inside of a PTAC unit or heat pump.
This solution is often used when no common wire exists between the existing thermostat and HVAC unit. It is intended to control the following types of HVAC systems with standard 24VAC connections:
- Fan Coil systems with multiple speeds
- PTAC units with standard thermostat connections
- Heat pump units, including emergency electric heat as well as configurable reversing valve control (with heat or with cool)
The large number in the middle of the TB-100 display represents the ambient (room) temperature; the small number on the right hand side of the display represents the set-point temperature.
There are 6 accessible buttons on the device:
- Temp Up: Each press of this button increases the setpoint by 1-degree. The thermostat will then prompt the user to select “Done” to immediately engage the new setpoint, or after a 5-second period it will automatically engage the new setpoint.
- Temp Down: Each press of this button decreases the setpoint by 1-degree. The thermostat will then prompt the user to select “Done” to immediately engage the new setpoint, or after a 5-second period it will automatically engage the new setpoint.
- ON/OFF: Pressing this button completely disengages the HVAC system, and “OFF” will be displayed on the graphical display. While in this mode, the thermostat will not call for heating, cooling, or any fan control. To re-engage the HVAC system, press the ON/OFF button again and the “OFF” display will disappear.
- System Mode (Auto, Heat, Cool): By default, the thermostat operates in “Auto changeover”, meaning it calls for either heating or cooling depending on the current room temperature vs. selected setpoint temperature. Pressing this button locks the thermostat into only calling for heating or cooling, and ignores setpoints that conflict with the manual heating or cooling setting.
- Fan Mode (High, Med, Low, Auto): The number of fan speeds visible and accessible by a user is dependent on the fan mode- for example, if the thermostat is configured as a 2 speed device, then only High, Low, and Auto will be able to be cycled. By default, the thermostat operates in “Auto” fan mode, whereby the fan speed selected is dependent on the delta between setpoint and current room temperature.
In a 2 speed configuration, the system operates in low fan speed when the delta between setpoint and current room temperature is 1-degree. The system operates in high fan speed when the delta is 2-degrees or greater.
In a 3 speed configuration, the system operates in low fan speed when the delta between setpoint and current room temperature is 1-degree. The system operates in medium fan speed when the delta is 2-degrees. The system operates in high fan speed when the delta is 3-degrees or greater.
- Fahrenheit/Celsius (F/C): Pressing this button cycles both the current and setpoint display temperatures between Fahrenheit and Centigrade.