BASstat Series BAST-121 Single Mode Thermostats

Product Overview

The BASstat series of BACnet-compliant wired or wireless communicating thermostats are BTL listed to ensure effortless integration into BACnet/IP (Wi-Fi) or BACnet MS/TP (EIA-485) networks. The BAST-121C is suited for single or multi-stage heating only or cooling only binary or analog output control applications, such as unitary heating or cooling units. The thermostat can control one or two stages of heating, one or two stages of Direct Expansion (DX) cooling, or a single 0-10V control output for either modulated heating or cooling. Configurable and adaptive control algorithm applied to multi-stage on/off control saves energy and ensures seamless comfort for the occupants. Three sensing options are available: built in temperature sensor, input for a remote temperature sensor, or temperature network command from a Building Automation System. Occupancy status can be set from thermostat buttons, a wired ESI input, or over the BACnet network. Thermostat buttons are optionally lockable to prevent tampering. Digital display with graphical icons is easy to read and understand.

Versatile BACnet Communication in Two Distinct Models

• BACnet MS/TP in B2 models with MS/TP baud rates 9.6kbps – 76.8kbps
• BACnet/IP in BW2 models with 802.11 b/g/n 2.4GHz Wi-Fi
• Both B2 and BW2 models are BACnet compliant and BTL listed

Flexible Installation

• 24VAC (+/-10%) power input
• Digital Display with graphical icons of operation, °C or °F display
• Designated heating or cooling mode with ventilation optional
• Occupied/Unoccupied modes with 2 sets of Cool/Heat set points
• Effective run time accumulation for energy consumption calculations
• Built-in temperature sensor
• Remote temperature sensor input (NTC Thermistor 3kΩ)
• Fully Configurable Algorithm control parameters: Stage Differential, Stage Width, Integral Time, Short Cycle, Cooling Short Cycle Delay Time, Maximum Cycles per Hour
• Non-volatile memory (EEPROM) retains user settings during power loss
• Lockable buttons/user interface
• Operating Environment: 0-50°C, 5-95% RH (non-condensing)
• Wiring: 16-18 AWG wires or 1.5 mm² wires
• Dimensions: 94×118×34 mm (W × H × D)
• Mounts directly onto wall, panel, standard 65×65 mm junction box (hole pitch 60 mm) or standard 2×4 inch vertical junction box (hole pitch 83.5 mm)

Product Details

The BASstat's backlit LCD display is large and easy to read. It incorporates graphical icons to aid visual indication of current state of operation. Several icons indicate parameters such as: Active Mode, Cooling stage 1 or 2, Heating stage 1 or 2, Ventilation Only, Fan Active, Occupied/Unoccupied state, and Clock icon to indicate Short Cycle Delay or Max Cycles per hour active waiting state. These icons are very useful in indicating the thermostat's current state of operation.

Six buttons on the BASstat allow users to manipulate set point, turn the thermostat ON/OFF, change modes, and more. Pressing the Up/Down buttons for more than 3 seconds can manually toggle the thermostat from occupied/unoccupied modes, where occupancy sensors are not an option. These buttons are lockable in a configurable manner. Some or all buttons can be locked for application flexibility, making the stat suitable for applications where limited user control is allowed.

The thermostat can be configured from the resident Engineering Menu or over the BACnet network. Two control types are available: Cooling only or Heating only. The default control type is Heating Only. These control types are selectable from the Engineering Menu or BACnet object. For configuration over the BACnet network, use our free BACnet Discovery Tool.

Ordering Information