Contemporary Controls BASstat BAST-221C-BW2 User manual

BAST-221C/CH-BW2
Wireless BACnet Communicating Thermostat for Multi-Stage Heating/Cooling/Ventilation
BASstat
Wireless Multi-Stage Thermostat
User Manual
# UM-15090500-AA1

UM-15090500-AA1 Page 1
Trademarks
BASautomation, Contemporary Controls, and CTRLink are registered trademarks of Contemporary Control
Systems, Inc. BACnet is a registered trademark of the American Society of Heating, Refrigerating and Air-
Conditioning Engineers, Inc. Powered by Sedona Framework is a trademark of Tridium, Inc. Other product
names may be trademarks or registered trademarks of their respective companies.
Copyright
© Copyright 2021, by Contemporary Control Systems, Inc. All rights reserved. No part of this publication may
be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or
computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical,
manual, or otherwise, without the prior written permission of:
Contemporary Control Systems, Inc.
Tel:
[phone]
2431 Curtiss Street
Fax:
[phone]
Downers Grove, Illinois 60515 USA
E-mail:
[email protected]
Contemporary Controls Ltd
Tel:
[phone]
14 Bow Court
Fax:
[phone]
Fletchworth Gate
E-mail:
[email protected]
Coventry CV5 6SP UK
Contemporary Controls (Suzhou) Co.
Ltd
Tel: [phone]
19F, Metropolitan Towers
Fax:
[phone]
No.199 Shishan Road
Suzhou New District
E-mail:
[email protected]
Suzhou PR China
215009
Contemporary Controls GmbH
Tel:
[phone]
Fuggerstraße 1 B
Fax:
[phone]
D-04158 Leipzig Deutschland
E-mail:
[email protected]
Disclaimer
Contemporary Control Systems, Inc. reserves the right to make changes in the specifications of the product
described within this manual at any time without notice and without obligation of Contemporary Control
Systems, Inc. to notify any person of such revision or change.

UM-15090500-AA1 Page 2
Contents
1Introduction.......................................................................................................................3
1.1 Features and Benefits.................................................................................................4
1.2 Product Image and Main Features..............................................................................5
2Specifications ...................................................................................................................7
2.1 Inputs..........................................................................................................................7
2.2 Outputs .......................................................................................................................7
2.3 Communication...........................................................................................................7
2.4 Electrical .....................................................................................................................7
2.5 Environmental.............................................................................................................8
2.6 Electromagnetic Compatibility.....................................................................................8
2.7 Mechanical (all dimensions are in mm).......................................................................9
3Installation ......................................................................................................................11
3.1 Terminal Block Pin Assignments ..............................................................................11
3.2 Limited Power Source...............................................................................................11
3.3 Power Supply Precautions........................................................................................12
3.4 Wiring Diagram .........................................................................................................12
4Operation........................................................................................................................13
4.1 User Mode ................................................................................................................13
4.2 Control Type .............................................................................................................15
4.3 Engineering Mode Menu...........................................................................................19
4.4 BACnet Objects and Network Configuration .............................................................26
5Warranty .........................................................................................................................40
6Returning Products for Repair ........................................................................................41
7Declaration of Conformity ...............................................................................................41

UM-15090500-AA1 Page 3
1 Introduction
The BAST-221C is a member of the BASstat BACnet Communicating Thermostat series. It
provides multi-stage heating and cooling control in an attractive wall-mounted enclosure with a
large LCD display. Intended for use with rooftop units (RTUs), the thermostat can control one or two
stages of heating and one or two stages of Direct Expansion (DX) cooling. The BASstat is BACnet
compliant and BTL listed to ensure seamless integration into BACnet networks. The BAST-221C-
BW2 communicates to a BACnet client over Wi-Fi and can be integrated into any 802.11 b/g/n Wi-
Fi network. 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. “221CH” thermostat models support relative humidity reading with a built-in
sensor which is shown on the display and as a BACnet object, as well as a calculated dew point
value as a BACnet object (no control action is taken based on humidity). Both models have five
relays – two for stage heating, two for stage cooling and one for fan. The BASstat is configurable
locally using the Engineering Menu or via a network connection to a BACnet client. Contemporary
Controls’ free BACnet Discovery Tool (BDT): www.ccontrols.com/sd/bdt.htm can be used for initial
discovery and configuration of the thermostat over BACnet. Control algorithm parameters such as
deadband, proportional gain, integral rate, stage trip points and stage widths are all configurable.
This BASstat also features configurable short-cycle protection, maximum cycles per hour, fan
control and occupancy selection. All states and pending delays 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.

UM-15090500-AA1 Page 4
1.1 Features and Benefits
•Stand-alone thermostat algorithm or fully BACnet network-controllable
•BTL listed with B-ASC device profile for seamless integration into BACnet networks
•24VAC (+/-10%) power input
•Manual-changeover or Auto-changeover control types
•BACnet/IP over Wi-Fi can be integrated into any 802.11 b/g/n Wi-Fi network
•Suitable for single to multi-stage heat/cool control applications with manual or
automatic changeover between heating and cooling modes
•Adjustable algorithm applied to multi-stage step control
•Adjustable minimum on/off time staging for optimizing runtime
•Effective run time accumulation for system runtime for energy consumption metering
•Full configurable control parameters such as deadband, proportional gain, integral
rate, stage trip points, and cycle time
•Adjustable minimum/maximum set point ranges
•Three options for temperature reading:
oBuilt-in temperature sensor, or
oRemote sensor (RS) input for wiring in a remote temperature sensor (NTC
3kΩ), or
oBACnet network temperature override
•Occupancy status can be switched from thermostat buttons by occupants or using
BACnet network command.
•Separate adjustable occupied set points for heating and cooling mode
•Separate adjustable unoccupied set points for heating and cooling mode
•Fan can be set to run continuously or automatically depending upon fan mode
•Non-volatile memory (EEPROM) retains user settings during power outage
•Thermostat buttons are selectively lockable to prevent unauthorized control
•°C or °F display
•Control outputs disabled during “OFF” state for safety

UM-15090500-AA1 Page 5
1.2 Product Image and Main Features
BASstat 221C-BW2

UM-15090500-AA1 Page 6
BASstat 221CH-BW2

UM-15090500-AA1 Page 7
2 Specifications
2.1 Inputs
Item
Description
Temperature Display Range
14 to 140°F (-10 to +60°C)
Temperature Display Resolution
0.1°F (0.1°C)
Temperature Accuracy
±1.8°F (±1.0°C) with all outputs off
Setpoint Range
32 to122°F (0 to 50°C) in 0.5° (°F or °C) increments
Remote Temperature Sensor
Provision for NTC Type 3kΩ thermistor
2.2 Outputs
Item
Description
Relay Outputs
Heating 1, Heating 2, Cooling 1, Cooling 2, Fan
Contact Rating
SPST 2A at 30 VAC with inductive load
Minimum contact life
100,000 cycles
2.3 Communication
Item
Description
Protocol Compliance
BACnet/IP with B-ASC, BTL Listed
Physical Layer
802.11 b/g/n Wi-Fi network
Cabling
None
2.4 Electrical
Item
Description
Supply Voltage and Current
24 VAC (±10%) 5 VA
Power Source Class
NFPA 70 (NEC) Article 725 Part III Class 2
Internal Power Supply
Half-wave rectified and filtered DC

UM-15090500-AA1 Page 8
2.5 Environmental
Item
Description
Operating Temperature
32°F to 122°F (0 to 50°C)
Storage Temperature
14 to 140°F (-10 to +60°C)
Relative Humidity
5 to 95% non-condensing
2.6 Electromagnetic Compatibility
The BAST-221C complies with the following specifications and bears the CE mark in accordance
with the provisions of the Electromagnetic Compatibility (EMC) Directive 2004/108/EC based on
the following specifications:
Standard
Test Method
Description
EN 61000-6-2
IEC 61000-4-2
Electrostatic Discharge Immunity
EN 61000-6-2
IEC 61000-4-3
Radiated, Radio-Frequency,
Electromagnetic Field Immunity
EN 61000-6-2
IEC 61000-4-4
Electrical Fast Transit/Burst Immunity
EN 61000-6-2
IEC 61000-4-5
Voltage Surge Immunity
EN 61000-6-2
IEC 61000-4-6
Immunity to Conducted Disturbances
EN 61000-6-2
IEC 61000-4-8
Power Frequency Magnetic Field
Immunity
EN 61000-6-2
IEC 61000-4-11
Voltage Dips and Interruptions
EN 61000-6-3
IEC 61000-3-2
Limits for Harmonic Current Emissions
EN 61000-6-3
IEC 61000-3-3
Limitation of Voltage Fluctuations and
Flicker in Low Voltage Supply Systems

UM-15090500-AA1 Page 9
2.7 Mechanical (all dimensions are in mm)
Wiring: 14 to 22 AWG wires or 1.5mm2 wires
Mounts directly onto wall, panel, standard 65×65mm junction box (hole pitch 60 mm) or
standard 2×4-inch vertical junction box (hole pitch 83.5mm)
Width: 94mm Height: 118mm Depth: 34mm

UM-15090500-AA1 Page 10

UM-15090500-AA1 Page 11
3 Installation
The BASstat is intended for surface-mount installation at eye-level on an interior wall, away from
direct sunlight or direct air movement. The display (top half) can be removed from its base by
loosening the small Philips screw at the bottom of the display. Once the display is removed from
the base, the base can be mounted onto the wall with appropriate fasteners. If a single-gang
electrical junction box is to be used, the top and bottom mounting holes will align with the screw
holes in the junction box.
3.1 Terminal Block Pin Assignments
Two 9-pin terminal blocks provide for all field connections. Terminal markings for mechanical
equipment follow NEMA DC 3-2003 convention. For single-stage operation, connect Y wire to Y1
and W wire to W1. The remote sensor input (RS) is at terminals 13 and 14. The remote
occupancy (ESI) input is a dry contact closure input located at terminals 14 and 15. The BASstat
is intended to be powered by a Class 2 compliant power source and only accepts 24VAC.
Number
Mark
Comment
Number
Mark
Comment
1
R
24 VAC high-side
10
2
C
24 VAC common
11
3
Y1
Cooling Stage 1
12
4
13
RS
Remote Sensor Input
5
Y2
Cooling Stage 2
14
GND
Ground
6
W1
Heating Stage 1
15
ESI
Energy Saving Input
7
W2
Heating Stage 2
16
8
G
Fan
17
9
18
3.2 Limited Power Source
The BASstat is intended to be powered by a Class 2 compliant power source and only accepts
24VAC with no more than 5VA of power consumption and should be powered by a Class 2 power
source complying with the requirements of the National Electric Code (NEC) article 725. The
power rating of a Class 2 power source is limited to 100 VA. The transformer or power supply
complying with the Class 2 rating must carry a corresponding listing from a regulatory agency
such as Underwriters Laboratories (UL).

UM-15090500-AA1 Page 12
3.3 Power Supply Precautions
Internally, the BASstat utilizes a half-wave rectifier and can share the same AC power source with
other half-wave rectified devices. Sharing AC power with full-wave rectified devices is NOT
recommended. AC power sources that power several half-wave devices have a common
secondary connection called COMMON, LO, or GROUND. Connect the HOT side of the
secondary to the 24 VAC high side input on the BASstat and the LO side to 24 VAC common.
WARNING: Devices powered from a common AC source could be damaged if a mix of half- wave
and full-wave rectified devices are both present. If you are not sure of the type of rectifier used by
another device, do not share the AC source with it.
3.4 Wiring Diagram
Wiring: 14 to 22 AWG wires or 1.5mm2 wires

UM-15090500-AA1 Page 13
4 Operation
4.1 User Mode
User-side control is accomplished with six buttons – MODE (Heat, Cool, or Ventilate), FAN (Auto
or Continuous), UP, DOWN, SET, and POWER. There are also options to lock select buttons or
all buttons on the thermostat to limit user access if so required. A large LCD display indicates
setpoint, space temperature, occupancy status, and current mode of operation using graphical
icons.
System modes (Cool, Heat, Ventilate) available to the user are dependent on control type chosen
from Engineering Menu (tyPE) or BACnet object [MSV7] Control Type. (See section 4.2 Control
Type of this manual). System modes and button operation may be limited by the installer,
especially if the thermostat is completely controlled over BACnet network.
The first tier of operation includes the following settings as shown below. To operate the
thermostat:
1. The POWER button toggles between ON or OFF states to start / stop the
thermostat outputs. This will disable control (ON/OFF control can be accomplished over
BACnet as well).
2. At power ON, press any button to start the User Mode operation. Press the MODE button
to toggle between different HVAC operating modes such as Cool, Heat, or
Ventilate@Cool and Ventilate@Heat.
Press the UP/ DOWN buttons to increase/decrease temperature
setpoint or rotate the values of a setting. Press the FAN button to toggle fan
modes of AUTO or CONTINUOUS. If no AUTO icon is displayed, the fan is in
CONTINUOUS fan mode and it will run continuously until commanded off using button on
thermostat or BACnet command. If AUTO icon is flashing, the fan is operating under delay
timer and will shut off automatically when delay timer expires.
Press the SET button and use UP/ DOWN buttons to toggle
the unit between Occupied or Unoccupied states when outside of scheduled operation. Use
SET or MODE to apply (SET button can be locked in applications forbidding occupancy
state user control).
3. Thermostat will return to normal display with the last known setting if there’s no button
pressed for 10 seconds.

UM-15090500-AA1 Page 14
User Mode Thermostat Operation
#
Item
Description
Remarks
1
Normal Display
Display current room or set-point
temperature
Use the (SP) parameter in
the Engineering Menu or
[MSV6] Display Option for
BW2 or [MSV7] Display
Option for B2 model to
choose Current room or Set-
point temperature on display.
2
Temperature
Setpoint
Setting using
Up/Down
Arrows
Set the desired temperature
The [AV0] / [AV3] Cool / Heat
Occupied and [
AV8] / [AV9]
Unoccupied Cool /
Heat
temperature setpoints BACnet
objects can be used to write or
force the setpoint to a desired
value from BACnet supervisor.
3
Mode Select
Select the working mode:
Cooling ( ), Heating ( ), or
Ventilating ( ).
After pressing the MODE
button, press the UP/ DOWN
button to rotate the selections.
Dependent on Control Type.
4
Fan Auto/
Continuo
us
Change the Fan mode between
Auto or Continuous.
When AUTO is displayed, the
fan is handled automatically.
When AUTO is flashing, the
fan is working under a delay
timer. When FAN icon is
spinning but AUTO is not
displayed, the fan will run
continuously until commanded
off.
5
Occupancy
Setting
Press SET, Used UP and DOWN
arrows to toggle between the
Occupied and Unoccupied setting.
Use MODE or SET buttons to
apply.
The SET button could be
locked for applications
forbidding user occupancy
state control.

UM-15090500-AA1 Page 15
User Mode Flow Chart
4.2 Control Type
Control Type, System Mode and Algorithm Configuration
The BAST-221C supports two different control types, selectable in Engineering Menu item
(tyPE) BACnet object [MSV7].
Control type is only configurable by the installer using Engineering Mode Menu or BACnet
supervisor. The installer must decide the control type suitable for the application, set it to a
static value, or program the BACnet supervisor to change the control type automatically. The
default control type is set to 2- stage Heating and Cooling with Auto Changeover. This is the
most common control type. 2- stage Heating and Cooling with Manual Changeover can be
used to limit frequent automatic change of system modes (Cool or Heat).
System modes available to the user are dependent on control type chosen from Engineering
Menu (tyPE) or BACnet object [MSV7] Control Type.
Dual Stage Heat and Cool with Auto Changeover - This the default control type in this
thermostat. Mostly used for standalone operation. The thermostat will switch between Cool
and Heat modes automatically. In this control type, the user will be presented with a choice of

UM-15090500-AA1 Page 16
Heat or Ventilation@Heat when the thermostat is in Heat mode (automatic), and Cool or
Ventilation@Cool when the thermostat is in Cool mode (automatic).
Dual Stage Heat and Cool with Manual Changeover – In this control type the thermostat will
wait for a command from user or BACnet supervisor to switch between Cool and Heat modes.
The user will be presented with a choice of Heat or Ventilation@Heat when the thermostat is in
Heat mode, and Cool or Ventilation@Cool when the thermostat is in Cool mode. The user can
choose to switch between Cool and Heat modes using the MODE button.
BACnet controlled – In this control scheme, the built-in thermostat algorithm can be bypassed,
and the thermostat can be controlled over the BACnet network with commands from the
supervisor device. The logic executing in the supervisor (such as Niagara or Sedona logic) can
control the thermostat over the BACnet network. To put the thermostat in BACnet network
control mode, use the Lock [AV18] object bit 9: Control DOs by thermostat algorithm “0”
(default) or BACnet supervisor “1” (add decimal=512).
Cool Only (nullified/disabled in firmware), and Heat Only (nullified/disabled in firmware) control
types are listed in the BACnet object and Engineering Menu object but are not available for
use.
Fan Output in Heat Mode
By default, the BASstat thermostat will not provide Fan output signal when in Heat Mode since
most HVAC comfort systems such as RTU systems provide their own fan control signal based
on a delay after a call for heating. This can be configured from Engineering Menu item (F-Ht)
or BACnet object [BV15] Fan Output For Heating. The default value is “0”. To enable fan
control signal output for heating coming from the BASstat, set this value to “1”.
Algorithm
•A PID adaptive control algorithm is applied to minimize overshoot, in addition to
proportional band (Stage Width) and derivative (Differential) calculation.
•When the thermostat is active (either the heating or cooling stage is on), a
“Working
( )” icon will be shown on the LCD.
•Stage 1 operation will show the icon ( ). Stage 2 operation will display ( ).

UM-15090500-AA1 Page 17
System Mode
•The default control type is 2-stage cooling and heating with automatic
changeover. This makes the thermostat operate fully stand-alone. Control Type
can be selected in (tyPe) or [MSV7]. Manual Changeover control type allows
restriction of mode selection to Cool only or Heat only in applications where
necessary.
•Occupied Cooling [AV0] and Heating [AV3] set points and Unoccupied Cooling
[AV8] and Heating [AV9] setpoints can be set individually for cooling and heating
modes, with either manual or automatic changeover control. Minimum deadband
[AV7] can be programmed as well.
•For cooling/ heating with manual changeover control, cooling or heating can be
selected by pressing the MODE button or using a BACnet command to object [
MSV1]. In application where user control needs to be limited, the lock button
function can be used to disable MODE button.
Fan Control Output
•Fan Output for Heating - the fan output for Heat mode is disabled “0” in [BV15]
by default. The thermostat lets the RTU circuity control the fan during Heat
mode. Fan output can be enabled “1” for Heat mode if desired [BV15].
•Lowest Fan Speed is the speed the fan will default to after a control action
(Heating or Cooling). If the lowest fan speed [MSV4] is set as “Stop (1)”, the fan
will be automatically shut off after the control action (Heating or Cooling) and a
2-minute fan-off time delay. During this delay time, the AUTO icon will be
flashing, and the fan will shut off after the 2-minute time delay expires. If lowest
fan speed is set to “Low (2)” the fan will run continuously after a control action.

UM-15090500-AA1 Page 18
This feature is useful for thermostat models with multiple fan speeds.
•Fan Mode can be toggled between AUTO or CONTINUOUS by using the FAN
button on the thermostat (user) or BACnet object [MSV0] Fan Mode (BACnet
supervisor). By default, this value is set to “Auto(1)”, the AUTO icon is displayed,
and the fan will be controlled automatically. To put the fan in CONTINUOUS
mode set to “Low(2)” this will cause the fan to run continuously (no AUTO icon is
displayed). Fan icon spinning when fan is active. Optionally, the FAN button can
be locked to limit user access to this feature or the BACnet supervisor can be
programmed to default the thermostat to certain state at the end of an
occupancy cycle.
Short Cycle and Maximum Cycles per Hour
•There are short cycle and maximum cycles per hour protection for both cooling
and heating modes [AV23 – 26] Cooling Short Cycle Delay, Cooling Maximum
Cycles per Hour and Heating Short Cycle Delay, Heating Maximum Cycles per
Hour.
•The short cycle time (in minutes) will determine the minimum on time and
minimum off time of each stage before changing its state. The default setting is
3 minutes.
•Maximum cycles per hour will count the number of cycles in an hour. When the
cycle count reaches the maximum cycles in an hour, it won’t allow additional
cycles until the next hour.
•When a stage change is pending due to a Short Cycle Delay or a Maximum
Cycle count, the Clock icon ) will appear on the LCD.
•To disable short cycle checking, set the short cycle to 0 minutes. NOTE: Do not
use this value unless the heating and cooling equipment is equipped with an
internal timer. Damage to equipment may occur.
Floating Deadband
•The Heat and Cool temperature setpoints could be “attached” together. This
means that as one setpoint is adjusted and “hits” against the deadband region, it
will “push” the deadband region and the other setpoint along the temperature
setpoint axis to allow for adjustment while maintaining the configured deadband.
If the setpoint is adjusted back the other way, it will “pull” the deadband region
and the other setpoint along the temperature setpoint axis.
Minimum Cooling Setpoint and Maximum Heating Setpoint
•Minimum Cooling Setpoint will be confined by set point low limit plus dead band
and Minimum cooling setpoint [AV-39] default: 18°C/65°F
•Maximum Heating Setpoint will be confined by set point high limit minus dead
band and Maximum heating setpoint [AV-40] default: 25°/77°F
Assigned Current Temperature

UM-15090500-AA1 Page 19
A current temperature value can be assigned thru BACnet AV-1 to take place of
the onboard temperature sensor value. The assigned value is valid if BACnet
communication is driving a flip-flop signal to (BV-16: heartbeat signal) within the
(AV-29: Heartbeat Rate time) period (in seconds). Otherwise, the assigned
temperature will revert back to the onboard sensor reading.
Occupancy Setting
There are three ways to define thermostat occupancy state. NOTE: Occupancy will be
detected by ESI contact by default.
•Energy Savings Input (ESI) This is a dry contact input meant for communication
from a customer supplied occupancy sensor. (default)
•Occupancy status (occupied/unoccupied) can be set by a BACnet supervisor
using writable object ESI Contact Definition [BV14]. “0” for occupied, and “1” for
unoccupied. E12/AV18 must be set with a value of 64 (disabled) in advance
(E12/AV18 is set as 0 by default)
•User control of occupancy state is allowed from the SET button if E12/ AV18
Lock has the ESI Contact disabled. Pressing the SET button and UP/DOWN
buttons will toggle the occupancy state. Press SET button to confirm. The SET
button can work in conjunction with BACnet occupancy Command [BV14] on
last-write-wins basis. The SET button could be locked to limit user control (use
Lock [AV18] BACnet object or (LOC) engineering menu item to lock SET
button). In this case only the BACnet supervisor can set occupancy states.
•Occupancy Status [BI0] is a read-only BACnet object indicating current
occupancy state - “0” for occupied, and “1” for unoccupied. (AV18 is set as 0 by
default).
•When in unoccupied state, a Moon ( ) icon will be displayed on the LCD and
the thermostat will change the set-point temperatures to the Unoccupied Cool
and Unoccupied Heat setpoints [AV8 – 9]. When the state changes back to
occupied, the thermostat will return to the occupied set-point values for Cooling
and Heating Temperature Setpoint [AV0, AV3] and a sunlight icon ( ) will be
displayed to indicate occupied state on LCD.
4.3 Engineering Mode Menu
Thermostat configuration can be performed using the engineering mode menu described
below or BACnet objects using a BACnet client tool such as Contemporary Controls free
BACnet Discovery Tool (BDT). It is highly suggested that engineering mode be operated by
trained installers only, because it is related to system parameters that will affect the control
results.
Operation of Engineering Menu
•At power “ON”, press and hold both the UP and DOWN buttons simultaneously
for 5 seconds to enter Engineering Mode menu.
•Press the UP or DOWN buttons to rotate through the menu items. The last item