1 Introduction
The BAST-321HP-B2 is a member of the BASstat BACnet Communicating Thermostat
series. It provides multi-staged heating and cooling control in an attractive wall-mounted
enclosure with a large LCD display. Intended for use with single and multiple stage heat
pump units, the thermostat can control 2 reversible DX heat pump compressors, one
binary reversing valve, one binary supply fan relay, plus one binary stage of auxiliary
heating (gas or electric). This BASstat is BTL listed to ensure seamless integration into a
BACnet network, using BACnet/MSTP over 2-wire EIA-485, and can be routed to
BACnet/IP clients using a Contemporary Controls BASrouter (BASRT-B). A large, easy to
read LCD display indicates setpoint, space temperature and current mode of operation
using graphical icons.
The BASstat has a built-in space temperature sensor with provision for remote wired 3kΩ
NTC thermistor sensor or temperature value can be sent by another communicating
device over the BACnet network. The BASstat is configurable locally using the
Engineering Menu or via a network connection to a BACnet client. Contemporary Controls’
free BACnet Discovery Tool can be used for initial discovery and configuration of the
thermostat over the network. Control algorithm parameters such as deadband,
proportional gain, integral rate and trip points are all configurable. This BASstat also
features configurable fan control and occupancy selection. Operating states are indicated
on the thermostat display.
The numerous features available in the BASstat can be configured by the systems
integrator to meet user requirements in two different ways. One way is using a button
sequence on the thermostat in order to enter the Engineering Menu - which requires
physical access to the thermostat. Optionally, the buttons could be locked to limit user
access to Engineering Menu after installation is complete. The second method is
configuring the thermostat over the BACnet network using a BACnet client device or
software such as Contemporary Controls’ free BACnet Discovery Tool (BDT).
