BASstat Series BAST-221 Thermostats

Product Overview

The BASstat series of BACnet-compliant wired or wireless communicating thermostats ensure effortless integration into BACnet/IP (Wi-Fi) or BACnet MS/TP (EIA-485) networks. These thermostats are suited for single or multi-stage heating, cooling and ventilation binary output control applications such as RTU or AHU. Configurable control algorithm parameters allow adaptability to the specific application. Adaptive control algorithm applied to multi-stage on/off control saves energy and ensures seamless comfort for the occupants. Built in temperature sensor, input for remote temperature sensor, or temperature override network command from Building Automation System. A built-in relative humidity sensor (in 221CH models) allows the thermostat to display relative humidity on the screen as well as serve it as a BACnet object, dew point calculation is also served as a BACnet object (no control action is taken based on humidity). Occupancy status can be set from thermostat buttons, a wired ESI input, or over the BACnet network. Thermostat buttons are optionally lockable to prevent unauthorized control or configuration changes. Digital display with graphical icons is easy to read and understand.

Versatile BACnet Communication in Two Options

• BACnet MS/TP in B2 models with MS/TP baud rates 9.6kbps - 76.8kbps (BTL Listed)
• BACnet/IP in BW2 models with 802.11 b/g/n 2.4GHz Wi-Fi
• Both B2 and BW2 models are BACnet compliant with a B-ASC device profile

Flexible Installation

• 24VAC (+/-10%) power input
• Digital Display with graphical icons of operation, °C or °F display
• Single or Multistage, Binary Outputs for RTU or AHU applications
• Manual or Auto-changeover modes
• Occupied/Unoccupied modes with 2 sets of Cool/Heat set points
• Effective run time accumulation for energy consumption calculations
• Built-in temperature sensor
• Built-in relative humidity sensor and dew point calculation value (in 221CH models)
• Remote temperature sensor input (NTC Thermistor 3kΩ)
• Networked current temperature override from BACnet client (BMS)
• Fully Configurable Algorithm control parameters: Deadband, Proportional Gain, Integral Rate, Stage Trip Points, Stage Widths, Short Cycle Delay, Maximum Cycles Per Hour
• Stand-alone operation with setpoints reset and schedule from BACnet BMS or optional full BACnet BMS control
• 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: 14 to 22 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 white backlit LCD display is large and easy to read, even from a distance. 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 temperature set point, change HVAC modes, turn the thermostat ON/OFF, and more. Pressing the Set and Up/Down buttons can manually toggle the thermostat from occupied/unoccupied modes, where BACnet occupancy command is not an option. All 6 of these buttons are lockable in a configurable manner to prevent unauthorized configuration change. Some or all buttons can be locked for application flexibility, making the stat suitable for applications where limited user control is allowed.

Sometimes the ideal location to install the thermostat is not the ideal location to capture a correct representation of the temperature in the room, either because it is near a draft, exposed to sunlight, directly under a ceiling fan, near exterior doors or close to equipment that create hot or cold air. In that scenario, a remote temperature sensor is available. Featuring an NTC type 3kΩ thermistor, the temperature sensor is directly compatible with any BASstat model.

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