Contemporary Controls BAST-221C, BASstat 221C-B2, BASstat Series, BASstat 221C-BW2 User Manual

BAST-221C

BACnet Communicating Thermostat for Multi-Stage Relay Heating/Cooling/Ventilation

BASstat

Binary (B2-BW2) User Manual

# UM-15090000-AA4

Trademarks

Contemporary Control Systems, Inc.

Tel:

[phone]

2431 Curtiss Street

Fax:

[phone]

Downers Grove, Illinois 60515 USA

E-mail:

[e-mail]

Contemporary Controls Ltd

Tel:

[phone]

14 Bow Court

Fax:

[phone]

Fletchworth Gate

E-mail:

[e-mail]

Coventry CV5 6SP UK

Contemporary Controls (Suzhou) Co.

Tel:

[phone]
11 Huoju Road

Fax:

[phone]

Industrial Park — Science &

E-mail:

[e-mail]

New District, Suzhou
Contemporary Controls GmbH

Tel:

[phone]

Fuggerstraße 1 B

Fax:

[phone]

D-04158 Leipzig Deutschland

E-mail:

[e-mail]

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 2018, 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:

Ltd

Technology

PR China 215009

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-15090000-AA4 Page 2

Contents

1 Introduction .............................................................................................................. 4

1.1 Features and Benefits ........................................................................................ 4

1.2 Product Image and Main Features ..................................................................... 6

2 Specifications ........................................................................................................... 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

3 Installation .............................................................................................................. 11

3.1 Terminal Block Pin Assignments ...................................................................... 11

3.2 Limited Power Source ...................................................................................... 12

3.3 Power Supply Precautions ............................................................................... 13

3.4 Wiring Diagram ................................................................................................ 13

4 Operation ............................................................................................................... 14

4.1 User Mode........................................................................................................ 14

4.2 Control Type..................................................................................................... 16

4.3 Engineering Mode Menu .................................................................................. 20

4.4 BACnet Objects and Network Configuration .................................................... 30

5 Warranty ................................................................................................................ 52

6 Returning Products for Repair ................................................................................ 53

7 Declaration of Conformity ....................................................................................... 54

UM-15090000-AA4 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. There
are two models with the only difference being the way the thermostat communicates to a
BACnet client. One model (B2) is BACnet MS/TP connected and can be routed to BACnet/IP
clients using a BASrouter (BASRT-B)
be integrated into any 802.11 b/g/n Wi-Fi network. User-side comfort control is accomplished
with six buttons – Mode (Heat, Cool, or Ventilation), Fan, Raise (Up Arrow), Lower (Down
Arrow), Set, and Power. There also are options to lock select buttons or all buttons on the
thermostat. 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. Both models have five relays – two for stage heating, two for stage cooling
and one for fan. The BASstat is configurable using its buttons and entering the Engineering
Menu or via a network connection to a BACnet client. Contemporary Controls’ free

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, stage
trip points and stage widths are all configurable. The BASstat also features configurable short­cycle 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

Discovery Tool (BDT). All features available are configurable using both methods.

. The other model, (BW2) is BACnet/IP over Wi-Fi and can

BACnet

BACnet

1.1 Features and Benefits

• Fully 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

• Two models of thermostats for BACnet communication options:

-B2 model - BACnet MS/TP with baud rate selections up to 76.8kbps

-BW2 model -BACnet/IP over Wi-Fi model 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

UM-15090000-AA4 Page 4

• 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:

-Built-in temperature sensor, or

-Remote sensor (RS) input for wiring in a remote temperature sensor (NTC 3kΩ), or

-BACnet 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-15090000-AA4 Page 5

1.2 Product Image and Main Features

BASstat 221C-B2 and BASstat 221C-BW2

UM-15090000-AA4 Page 6

2 Specifications

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

32-122°F (0-60°C) in 0.5° (°F or °C) increments

Remote Temperature Sensor

Provision for NTC Type 3kΩ thermistor

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

Item

Description

Protocol Compliance

BACnet MS/TP or BACnet/IP with B-ASC, BTL Listed

Physical Layer

2-wire, non-isolated EIA-485, no built-in EOL termination

Baud Rate

9.6, 19.2, 38.4, 76.8 kbps (default 38.4 kbps), N81 format

Cabling

Single-pair twisted 24GA with shield

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

2.1 Inputs

2.2 Outputs

2.3 Communication

2.4 Electrical

UM-15090000-AA4 Page 7

2.5 Environmental

Item

Description

Operating Temperature

32°F to 122°F (0 to 50°C)

Storage Temperature

-40°F to +85°F (-40°C to 30°C)

Relative Humidity

5 to 95% non-condensing

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,

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

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

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:

Electromagnetic Field Immunity

Immunity

Flicker in Low Voltage Supply Systems

UM-15090000-AA4 Page 8

2.7 Mechanical (all dimensions are in mm)

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-15090000-AA4 Page 9

UM-15090000-AA4 Page 10

3 Installation

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

7

W2

Heating Stage 2

16

D+

BACnet MS/TP Data +

8

G

Fan

17

D-

BACnet MS/TP Data -

9

18

The BASstat is intended for surface-mount installation at eye-level on a wall, not subjected to
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. There is no need to remove the
screw. Once the display is removed from the base, the base can be mounted onto the wall with
appropriate fasteners. The dimensions of the oval mounting holes are 4mm x 6mm allowing for
perfect fit adjustments. 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. Thanks to its EEPROM, the
BASstat will store its configuration in the event of power loss.

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. BACnet MS/TP data communication connections can be found at
terminals 16 and 17 and are polarity sensitive. The BASstat (B2 MS/TP model) does not provide
End-of-Line termination. If the BASstat-B2 is the first or last device on the MS/TP bus, a
termination resistor (120Ω) must be applied across pins 16 and 17 of the input terminal. The
remote sensor input (RS) is at terminals 13 and 14. The BASstat is intended to be powered by a
Class 2 compliant power source and only accepts 24VAC.

UM-15090000-AA4 Page 11

3.2 Limited Power Source

The BASstat thermostats accept 24VAC only with no more than 5VA of power consumption and
should be powered by a limited power source complying with the requirements of the National
Electric Code (NEC) article 725 or other international codes meeting the same intent of limiting
the amount of power of the source. Under NEC article 725, a Class 2 circuit is that portion of the
wiring system between the load side of a Class 2 power source and the connected equipment.
For AC or DC voltages up to 30 volts, 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-15090000-AA4 Page 12

3.3 Power Supply Precautions

Internally, the BASstat utilizes a half-wave rectifier and therefore can share the same AC power
source with other half-wave rectified devices. Sharing AC power with full-wave rectified devices
is NOT recommended. Full-wave rectified devices usually require a dedicated AC power source
that has a secondary elevated above ground. Both secondary connections are considered HOT.
AC power sources that power several half-wave devices have a common secondary connection
called COMMON, LO, or GROUND. This connection might be tied to earth. The other side of
the secondary is considered the HOT or HI side of the connection. 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 on
the BASstat. All other half-wave devices sharing the same AC power source need to follow the
same convention.

WARNING: Devices powered from a common AC source could be damaged if a mix of half­wave and full-wave rectified devices exist. 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

UM-15090000-AA4 Page 13

4 Operation

4.1 User Mode

User-side comfort 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 required in certain
applications. 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 for BW2 model
and [MSV8] Control Type for B2 model. (See section 4.2 Control Type of this manual).
System modes and button operation may be limited by installation engineer, 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. 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-15090000-AA4 Page 14

User Mode Thermostat Operation

# Item

Description

Remarks

1

Normal Display

Display current room or set-point

Use the (SP) parameter in

point temperature on display.

2

Temperature

Set the desired temperature

The [AV0] / [AV3] Cool / Heat
Occupied and [
Unoccupied
t

BACnet
objects can be used to write or
force the setpoint to a desired
value from

3

Mode Select

Select the working mode:

Ventilating (

).

After pressing the MODE

4

Fan Auto/

Change the Fan mode between

When AUTO is displayed, the

continuously until commanded
off.

5

Occupancy Setting

Press SET, Used UP and DOWN

apply.

The SET button could be
locked for applications
forbidding user occupancy
state

Setpoint Setting
using Up/Down
Arrows

Continuous

temperature

Cooling ( ), Heating ( ), or

Auto or Continuous.

the Engineering Menu or
[MSV6] Display Option for
BW2 or [MSV7] Display
Option for B2 model to
choose Current room or Set-

AV8] / [AV9]

Cool / Heat

emperature setpoints

BACnet supervisor.

button, press the UP/ DOWN
button to rotate the selections.
Dependent on Control Type.

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

UM-15090000-AA4 Page 15

arrows to toggle between the
Occupied and Unoccupied setting.
Use MODE or SET buttons to

control.

User Mode Flow Chart

4.2 Control Type

Control Type, System Mode and Algorithm Configuration

Both binary thermostat models (B2 and BW2) support two different control types, selectable in
Engineering Menu item (tyPE) or BACnet object [MSV8] Control Type for B2 model or [MSV7]
Control Type for BW2 model.

Control type unlike thermostat system mode, is not selectable by the end user, only configurable
by the installation engineer using Engineering Mode Menu (manual) or BACnet supervisor using
BACnet commands (commanded by BACnet supervisor). The engineer installing the thermostat
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 based on logic for the application
requirements such as change of seasons or geolocation. The default control type is set to 2­stage Heating and Cooling with Auto Changeover. This is the most common control type. 2­stage Heating and Cooling with Manual Changeover can be used to limit frequent automatic
change of system modes (Cool or Heat).

UM-15090000-AA4 Page 16

System modes available to the user are dependent on control type chosen from Engineering
Menu (tyPE) or BACnet object [MSV7] Control Type for BW2 model and [MSV8] Control Type
for B2 model.

Dual Stage Heat and Cool with Auto Changeover - The default control type in the thermostat is
set to Heat and Cool with Auto Changeover. Mostly used for standalone operation. Based on an
algorithm using setpoint, current temperature, and deadband, the thermostat will switch
between Cool and Heat modes automatically. In this control type, the user will be presented with
a choice of 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 – This control type is similar to Heat and
Cool with Auto Changeover but in this control type the thermostat will wait for a command from

user or BACnet supervisor to switch between Cool and Heat modes. In this control type, the
user will be presented with a choice of Heat or Ventilation@Heat when the thermostat is in Heat
mode (manual command), and Cool or Ventilation@Cool when the thermostat is in Cool mode
(manual command). The user can also choose to switch between Cool and Heat modes using
the MODE button.

BACnet controlled – The built-in thermostat algorithm can be bypassed completely, and the
thermostat can be controlled over the BACnet network with commands from 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.
They are nullified/disabled in the firmware.

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-15090000-AA4 Page 17