Introduction - Contemporary Controls BASstat BAST-421C-B2 User Manual

1 Introduction

The BAST-421C-B2 is a member of the BASstat BACnet Communicating Thermostat series. It
provides modulated heating and cooling control in an attractive wall-mounted enclosure with a
large LCD display. Intended for use with 4-pipe heated/chilled water Fan Coil units, the
thermostat can control 2 analog modulating water valve actuators and one binary supply fan.
This BASstat is BACnet compliant and BTL listed to ensure seamless integration into a BACnet
network, using BACnet/MSTP over 2-wire RS-485, and can be routed to BACnet/IP clients using
a Contemporary Controls BASrouter (BASRT-B). A large and 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 BACnet. 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. All
states are indicated by graphical icons 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). All features available are configurable using both methods.
NOTE: 2-pipe heat/cool applications and floating-type valve actuators are not supported by this
device.
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