Table of Contents
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Product Description
The DNT-T221-FCU is a packaged product consisting of a DNT-T221
and an FCM relay module, designed for use with a multi or variable
speed Fan Coil units. The product makes use of the relay board and the
DNT's analog output in order to control the fan.
The DNT-T221 is an intelligent room thermostat with a custom 3-value,
96 segment, LCD display. The DNT communicates directly on a
BACnet MS/TP network. It is capable of displaying a wide-range of
digital or analog values, including setpoints, temperature, heating and
cooling status, fan speed, valve position and more.
When connected on a BACnet MS/TP network the DNT-T221-FCU
functions as an independent BACnet thermostat. The firmware can be
flash loaded over the network, and have jumper selectable termination
resistors.
The DNT-T221 has 3 inputs, 2 analog outputs, 1 binary output and a
built-in Fan Coil application control strategy. As a result, this BACstat is
capable of stand-alone control when directly connected on an MS/TP
network.
Contents
Delta Network Thermostat: BACstat III
Application Guide ........................................................................... 1
Contents ....................................................................................... 1
Important Information ................................................................... 2
Setup & Configuration .................................................................. 3
Software & Programming ........................................................... 10
Control Functions ....................................................................... 14
Output Functions & Types .......................................................... 22
OWS Functions .......................................................................... 25
Appendix A: Programming Notes ............................................... 28
Appendix B: Two Pipe Fan Coil Configuration ........................... 29
Appendix C: Four Pipe Fan Coil Configuration .......................... 30
Application Guide
Document Edition 1.3
DNT-T221-FCU
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Related Manuals for Delta Controls BACstat III DNT-T221-FCU
Summary of Contents for Delta Controls BACstat III DNT-T221-FCU
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Page 1: Table Of Contents
Application Guide Delta Network Thermostat: BACstat III DNT-T221-FCU Document Edition 1.3 Product Description The DNT-T221-FCU is a packaged product consisting of a DNT-T221 and an FCM relay module, designed for use with a multi or variable speed Fan Coil units. The product makes use of the relay board and the DNT’s analog output in order to control the fan. -
Page 2: Important Information
DNT-T221-FCU Application Guide Important Information Related Documents The following documents are available for download from Delta Controls support site at https://support.deltacontrols.com. • Delta Controls Wiring Guidelines • ORCAview Technical Reference Manual • Associated BACstat Installation Guide (DNT-T221-FCU) • Release Notes for relevant firmware and BACstat products Although BACstat firmware is independent from ORCAview, System Controllers, and Application Controllers, certain BACstat capabilities require support from the other products. -
Page 3: Setup & Configuration
Document Edition 1.3 Setup & Configuration Network Communications On an MS/TP network, BACstats communicate at a default speed of 76,800 bps. Refer to the DNT- T221BX-FCU Release 4 Application Guide for network installation details. Flash Programming BACstat III offers flash loadable firmware across a network connection. It is supported by Flashloader V3.33+, and operates the same way as other Delta controllers. - Page 4 DNT-T221-FCU Application Guide Button & Navigation Functions The buttons functions as follows, within the Configuration Menu: Button Description • Represents a value of 0 when entering the PIN access code. Top Left ( • Previous: Enter the current setting (and go backward in the menu). •...
- Page 5 Document Edition 1.3 Configuration Menu Options Navigate the Configuration Menu to make changes to the device setup. Menu Item Description Displayed momentarily to indicate you have successfully entered the Configuration Menu. [Application] The Control Application (AV12). Only the following application is available: •...
- Page 6 DNT-T221-FCU Application Guide Menu Item Description - Setpoint is always displayed (adjustable) - No Setpoint until an arrow button is pressed (not adjustable) - Setpoint is always displayed (not adjustable) - Temperature from AI1 - Value from AI2 - Humidity from AI3 - Value from AV5 House &...
- Page 7 Document Edition 1.3 Menu Item Description The LINKnet Communications Setting (On or Off), to match the connection method. The should be set to Off when connecting to MS/TP. The DNA Setting (On or Off), for inheriting a derived address from system ...
- Page 8 DNT-T221-FCU Application Guide • Navigate to the desired item and use the arrow buttons to make any necessary changes. Once the changes are made press Next or Previous to save and move to the next option. • After 30 minutes, the BACstat exits the Service Tool Mode and returns to normal display mode. Any outputs commanded manually remain in manual.
- Page 9 Document Edition 1.3 Input Scale Ranges Local Input Scale Ranges are selected by setting the units, from the following available options. Input Valid Units Scale Description Application Notes C / F Standard 10K Thermistor (in ºC Only available options for AI1. or ºF) Contact closure sets FCU mode to unoccupied.
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Page 10: Software & Programming
DNT-T221-FCU Application Guide Software & Programming Objects The following is a list of predefined objects that reside in BACstat III products which cannot be created or deleted. When connected to an MS/TP network, these objects are accessible over the network. Object Name Description... - Page 11 Document Edition 1.3 AV28 Output3 Bin Delay Seconds As required Displays cooling output when AV5 is set to “yr” in Multispeed Fan/4-Pipe mode AV29 Setup 6 Setup Variable 6 (Name Changes) As required Displays heating output when AV5 is set to “yr”...
- Page 12 DNT-T221-FCU Application Guide System Log (AV35) The Description field in this object provides a log of the ten most recent events. If the time and date were previously set, then the event time is displayed. Each log entry has the format [dd/mm/yy hh:mm:ss ***] where *** is the event code.
- Page 13 Document Edition 1.3 Programming (MS/TP Connection) Objects All of the existing predefined BACstat III objects are readily accessible over the MS/TP network. Control Applications BACstats with I/O may be configured to run only the Fan Coil built-in control application. Another option disables local control altogether.
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Page 14: Control Functions
DNT-T221-FCU Application Guide Control Functions Overview Control Applications When connected to an MS/TP network, the BACstat can be configured to operate in a Fan Coil application control strategy and displayed in the Application variable (AV12). Application Description AV12 Provides control of a Fan Coil Unit with heating/cooling and a fan. - Page 15 Document Edition 1.3 Software Controller Loop General The operation of the BACstat III is centered on a software controller. The controller uses the following parameters in its operation. Parameter Object Default Value Notes Room Temperature Input 1 Temperature Occupied: Uses Day Setpoint (AV6) Setpoint Unoccupied: Uses Night Heat Setpoint (AV10) if the Input is below the Night Heat Setpoint (AV6);...
- Page 16 DNT-T221-FCU Application Guide • If the Input temperature is between these two extents for Heating and Cooling, then the controller is in a null zone For all control applications the Controller Status (AV14) modulates from -100 to 100% and sequences any necessary output stages.
- Page 17 Document Edition 1.3 Day Minimum Setpoint (AV7) – This is the minimum value to which a user can adjust the Day Setpoint. If a lower value is commanded from the OWS or another device, it will not accept the change. The value for Day Minimum Setpoint can be set in the Configuration Menu, or by commanding the variable (via GCL+ or ORCAview OWS or 3 Party devices).
- Page 18 DNT-T221-FCU Application Guide Control Diagram The following diagram displays occupied mode and helps illustrate the relationship between the internal software loop controller and various objects, including outputs. Fan (Multi or Variable Speed) Output 1 BACstat Buttons Constant Fan (mFnC/VFnC) (or remote Manual Fan Analog (Direct only) command via...
- Page 19 Document Edition 1.3 Control Applications Fan Coil Unit (FCU) – [Application (AV12) = 4] Function: Control of a Fan Coil Unit with a single or multi-speed fan. DNT-T221-FCU I/O (Outputs 1 & 2 are Analog, and Output 3 is a Triac) Input AI1 Input AI2* Input AI3...
- Page 20 DNT-T221-FCU Application Guide Sequence of Operation The fan coil application is designed to be used with multiple and variable speed fans. A relay board (FCM) is used to convert an analog output into 1, 2 or 3 binary outputs in order to control a multi-speed fan.
- Page 21 Document Edition 1.3 Heat/cool four pipe configuration Heating Control Ao2 H/C Control Cooling Control Bo3 Mode Output 2 is connected to the FCM. The FCM steers this signal to the Cooling Valve terminal or the Heating Valve terminal. Output 3 is used internally in the FCM to route the controlling signal to either the heating control valve or the cooling control valve.
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Page 22: Output Functions & Types
DNT-T221-FCU Application Guide Output Functions & Types The binary TRIAC output of the DNT-T221-FCU is capable of switching up to 24 VAC at a maximum of 0.5 A, and may be configured as binary or PWM, see table below. The DNT-T221-FCU supports two 0- 10v outputs, up to a maximum of 20 mA each. - Page 23 Document Edition 1.3 Types Output Type Description Action Code Binary Provides On/Off control with a triac output. Direct Revers Provides modulating control using a Pulsed Direct Width Modulation signal with a triac output. Revers Analog Provides modulating control using a 0-10v Direct ...
- Page 24 DNT-T221-FCU Application Guide 2.93 Sec. 0.59 Sec. 100% If the output using PWM is also configured as reverse acting then the output device will be considered to be reverse acting (i.e., Normally Open) and the input value will be inverted internally before being applied to the physical output.
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Page 25: Ows Functions
Document Edition 1.3 The FCM, which provides the fan switching for single, multi, or variable-speed fans, is always connected to Analog Output(1) of the DNT-T221-FCU. This output can only be configured as direct acting. Each configuration has a specific sequence of operation that is tailored to control that type of terminal unit. - Page 26 DNT-T221-FCU Application Guide • Day Setpoint: AV6 • Day Minimum: AV7 • Day Maximum: AV8 • Day Differential: AV9 • Night Heat Setpoint: AV10 (which can only be changed remotely, not via the keypad) • Night Cool Setpoint: AV11 (which can only be changed remotely, not via the keypad) Additional Settings These are additional settings you may also want to set from the OWS, and may be commanded as necessary, but rarely are once they have been set (or the control loop has been tuned).
- Page 27 Document Edition 1.3 Reconfigure If DNA is enabled on the BACstat, this will re-configure its address by deriving portions of it from other higher-level devices (for Area and System numbers). BACstat DNA addressing limited to 4194199. Reset This will reset the device, similar to powering it off and then back on again. Reload •...
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Page 28: Appendix A: Programming Notes
DNT-T221-FCU Application Guide Appendix A: Programming Notes The following provides additional important programming information. Configuration Variables (AV12 & AV21-23): These variables should never be commanded on the fly from a GCL+ program (or user command). They must be configured in the proper sequence and they radically alter operation too much to make frequent changes. -
Page 29: Appendix B: Two Pipe Fan Coil Configuration
Document Edition 1.3 Appendix B: Two Pipe Fan Coil Configuration Fan Coil Controller 2-Pipe Auto Changeover H / C RETURN DISCHARGE COIL OPTIONAL CHWR CHWS 77.0 STG2 elta XXX.AI1 SPACE TEMPERATURE (INTERNAL) XXX.AI2 INTERLOCK INPUT (CLOSE TO STOP) OPTIONAL XXX.AI3 SUPPLY WATER TEMP (CH’OVER) 0.5A BAC ID... -
Page 30: Appendix C: Four Pipe Fan Coil Configuration
DNT-T221-FCU Application Guide Appendix C: Four Pipe Fan Coil Configuration Fan Coil Controller 4-Pipe Heating / Cooling RETURN DISCHARGE COIL COIL OPTIONAL DNT-T221-FCU CHWR CHWS 77.0 STG2 elta XXX.AI1 SPACE TEMPERATURE (INTERNAL) XXX.AI2 INTERLOCK INPUT (CLOSE TO STOP) OPTIONAL XXX.AI3 SUPPLY AIR TEMPERATURE OPTIONAL 0.5A...
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