Danfoss MCX08M User manual

REFRIGERATION &
AIR CONDITIONING DIVISION User manual
MAKING MODERN LIVING POSSIBLE
Danfoss Electronics spa
Air handling Seq.
control algorithm
Software version 2.1

DKRCC.PS.RI.A1.02 / 520H4358 - Air Handling Seq. user manual - V 2.2
Produced by Danfoss Electronics spa Graphic Department, 10-2009
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Danfoss Electronics spa
Air Handling seq. - user manual
Index
1| Introduction 4
2| User interface 5
2.1| Keyboard 5
2.1.1| Direct access to special functions 5
2.1.2| Menu navigation 5
2.2 Turning the unit ON and OFF 5
2.3| Main screen 6
2.3.1| LED Display 6
2.3.2| LCD Display 7
2.4| Menu-based navigation 8
2.4.1| Displaying and managing alarms 9
2.4.2| Login 9
2.4.3| Parameters 10
2.4.4| Displaying the input/output values 10
2.4.5| Utilities 11
3| Conguring the AHU software 13
3.1| Conguration overview 13
3.2| Input/Output conguration 14
4| Coils control 17
4.1| Assign a control sequence to a coil 17
4.2| Coil output management 18
4.3| Valve control 19
4.3.1| ON/OFF and 0/10V valve control 19
4.3.2| 3-point valve control 20
4.4| Step control 21
4.4.1| Linear step switch 21
4.4.2| Variable step switch 22
4.4.3| Binary step switch 23
4.5| Locking sequences 24
4.6| Pumps control 25
4.7| Single Heat/Cool coils 26
4.8| Cooling coil defrost control 27
4.9| Heat/Cool request 27
5| Dampers and Energy recovery control 28
5.1| External and Mixing dampers 28
5.1.1| ON/OFF dampers 29
5.1.2| 0/10V dampers 29
5.1.3| Damper locked 29
5.2| Energy recovery 30
6| Temperature control sequences 31
6.1| Damper control sequences 31
6.1.1| Freecooling/Freeheating selection 32
6.1.2| Minimum opening 32
6.2| Heat and cool control sequences 33
6.3| Connection of setpoint sequences 35
6.4| Main setpoint 36
6.5| Local setpoint 37
7| Cascade Control 38
8| Examples 39
8.1| Example 1 39
8.2| Example 2 40
9| Frost protection 42
10| Controlling the supply temperature limits 43
10.1| Supply temperature limits in cascade control 43
10.2| Supply temperature lower limit 43
10.3| Supply temperature upper limit 44
11| umidity control 45
11.1| Control sequences 46
11.2| Humidier control 46
11.3| Dehumidier control 47
11.3.1| Cooling coil in dehumidication 48
11.4| Controlling the supply humidity limits 49
11.4.1| Upper limit 50
11.4.2| Lower limit 50
12| Supply and return fans 51
12.1| Type of supply and return fans 51
12.2| Fan speed conguration 53
12.3| Fans and antifreeze 54
12.4| Fans lock 54
13| Air quality control 55
14| Alarms 56
14.1| Actions following an alarm 56
14.2| Types of reset 56
14.3| Alarms table 56
15| Parameters 59

Danfoss Electronics spa
Air Handling seq.- user manual
DKRCC.PS.RI.A1.02 / 520H4358 - Air Handling Seq. user manual - V 2.2
Produced by Danfoss Electronics spa Graphic Department, 10-2009
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15.1| Parameters table 59
16| Modbus Communication 60
16.1| Table of exported variables 60
17| APPENDIX – Use of the Congurator 67
17.1| Guide to modifying the application software 67
17.2| “Parameters”Page 67
17.3| “Alarms”Page 68
17.4| “Parameters_x_Model”Page 68
17.5| I/O conguration pages 68

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Danfoss Electronics spa
Air Handling seq. - user manual
1| Introduction
The algorithm is aimed at controlling the main types of air treatment units.
It can run on the entire line of MCX systems and envisages the use of a remote MMI interface, Modbus
communication and EXC06 expansion.
It can handle the following main functions:
control of heating and cooling coils using PID logic and cascade control;
control of fans according to air pressure using PID logic;
humidity control;
air quality control;
“freecooling”and “freeheating”;
energy recovery;
limiting of supply temperature and humidity;
management of ON/OFF, 3-point, 0/10V valves;
management of ON/OFF and 0/10V dampers;
frost protection.
The type of AHU to be controlled is dened by conguring the parameters and dening the inputs and outputs
to be used to control the various elements that make up the AHU.
Both the parameters and the inputs and outputs can be congured from the instrument user interface or from
a PC using the Congurator software “AHU_Interface_vNN.xls” supplied with the algorithm (see "17] APPENDIX
– Use of the Congurator").*
Note
* In the latter case, it is possible to
generate as many binary
application les as the number of
congurations desired and, after
loading them into the MMIMYK
accessory, select the
conguration to download onto
the MCX on a case-by-case basis.
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Danfoss Electronics spa
Air Handling seq.- user manual
DKRCC.PS.RI.A1.02 / 520H4358 - Air Handling Seq. user manual - V 2.2
Produced by Danfoss Electronics spa Graphic Department, 10-2009
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2| User interface
2.1| Keyboard
Key Function
Up
Down
Enter
Esc
Keys are used to access directly some special functions and to navigate through the user interface menu.
2.1.1| Direct access to special functions
for 1s: access the alarms screen (see “2.4.1] Displaying and managing alarms”).
for 3s: access the main setpoint (see “6.4] Main setpoint”).
for 1s: access the menu.
for 3s: switch between ON/OFF status (see “2.2] Turning the unit ON and OFF”).
2.1.2| Menu navigation
Press for 1s to access the menu. Use the and keys to navigate through the menu; pressing lets you
descend a level in the menu, if this is possible, and pressing lets you move up a level.
Use the following keys to modify the selected parameters: , to enter the modication mode, and to
modify the value, to conrm the modication and to abandon it without conrming.
2.2| Turning the unit ON and OFF
The instrument can be switched from OFF to ON and vice versa in the following ways:
pressing the key and keeping it pressed for 3s;
using the digital“ONF - ON/OFF” input, if present; remember, the digital input acts on the status change.;*
Note
* if, during the input
conguration phase, you set
“Polarity”=N.C., the unit is OFF
when the input is open;
from a Modbus supervisor through coil 129, (see “16.1] Table of exported variables”).
When OFF, the machine mode is indicated as OFF on the main screen.
Passing from OFF to ON turns on the main screen.
Activating of the digital and analog outputs is delayed, respectively, by the dOt and AOt times
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DKRCC.PS.RI.A1.02 / 520H4358 - Air Handling Seq. user manual - V 2.2
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Danfoss Electronics spa
Air Handling seq. - user manual
UNIT ON AND OFF
GEN General Min Max Default U.M. Text value
ODL Out Delay
dOt Digital output delay 0 9999 10 sec
AOt Analog output delay 0 9999 10 sec
Tab.1_[User interface - Unit on and o]
2.3| Main screen
From the main screen, press and keep it pressed for 1 second to access the menu (see ”2.4] Menu-based
navigation”).
Note
*After ve minutes of inactivity,
the main screen is automatically
shown.
The main screen varies depending on whether a LED or LCD display is being used.
2.3.1| LED Display
Fig 1_[User interface - LED display]

Danfoss Electronics spa
Air Handling seq.- user manual
DKRCC.PS.RI.A1.02 / 520H4358 - Air Handling Seq. user manual - V 2.2
Produced by Danfoss Electronics spa Graphic Department, 10-2009
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LED DISPLAY
GEN General Min Max Default U.M. Text value
dSP Out Delay
dSA Display A value 1 17 RET ;NO;StH;StC;SUP;REt;OUt;tH1;tH2
;tC1;tC2;bAR;SHU;RHU;OHU;THU
;CO2;VOC
dUA Unit of measure A 1 4 °C ;NO;°C ;RH%;bAR
dSb Display B value 1 17 StH ;NO;StH;StC;SUP;REt;OUt;tH1;tH2
;tC1;tC2;bAR;SHU;RHU;OHU;THU
;CO2;VOC
dUb Unit of measure B 1 4 °C ;NO;°C ;RH%;bAR
Tab 2 _ [User interface -LED display]
Using dSA and dSB, you can choose which setpoint and probe reading values are to be shown on displays A and B
respectively.
dUA and dUb establishes the unit of measure used on the display A and B . The choices are: none, °C, RH%, bar.
The meaning of the icons is indicated in the gure.
The icon associated with a given function follows the trend in activation/deactivation for that function.
2.3.2| LCD Display
The rst screen displays:
the measurement detected by the two analog inputs (see “display
A” and “display B”for the version with LED display);
the symbols of the main active functions (see gure).
Fig 2 _ [User interface - LCD display]
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Air Handling seq. - user manual
2.4| Menu-based navigation
Press for 1 second to access the menu described in the table below.
MENU-BASED NAVIGATION
Menu Submenu Submenu Function Notes
LED
code LCD description LED code LCD description LED code LCD description
ALA Alarms Accesses the alarms
menu
AAL Active Lists all currently active
alarms
SAL Historic Presents the alarms
history
RAL Reset Used to reset alarms
that are reset manually
LOG Login Login Species the degree of
access to menus and
parameters.
The password is the
one indicated by the
parameters L01, L02
and L03
PAR Parameters Accesses the
parameters menu You must login rst.
For a description of the
parameters menu, (see
“15 Parameters”)
…. Parameters menu See the Congurator
software AHU_
Interface_vNN.xls
IO Input/Output
IOd I/O Values Displays the input and
output values
IOC I/O Cong Accesses the input/
output conguration
menu
(only if enabled through
the Congurator
Software)
dI Digital Input Conguration of the
digital inputs
dO Digital Output Conguration of the
digital outputs
AI Analog Input Conguration of the
analog inputs
AO Analog Output Conguration of the
analog outputs
UtI Utilities Accesses the utilities
function
COM Commissioning Enable commissioning
screen
DEF Load Default Load default
parameters
RTC Clock Setup Set date and hour Only for models tted
with real time clock
LON Lock Fan Stop and lock fans
LOF Unlock Fan Unlock fans
WIN Winter Sets the winter
operating mode
SUM Summer Sets the summer
operating mode
Tab 3 _ [User interface -Menu-based navigation]

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Air Handling seq.- user manual
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Use the and keys to navigate through the menu; pressing lets you descend a level in the menu, if this is
possible, and pressing lets you move up a level.
Use the following keys to modify the selected parameters: , to enter the modication mode, and to
modify the value, to conrm the modication and to abandon it without conrming.
2.4.1| Displaying and managing alarms
Menu: ALA – Alarms
Sub-menu: AAL – Active
Displays the active alarms.
Screen with description of the alarm (LCD), alarm code and number of active alarms.
Note that you can go to the alarm screen pressing the key directly from the main screen.
Each screen is dedicated to a specic alarm. Use the and keys to move from one screen to the next.
Press to reset the alarm currently displayed. To reset all alarms keep pressed for 5 seconds or use the
sub-menu “RAL – Reset”.
Sub-menu: SAL – History
Displays the history of the alarms which are no longer active.
The screens present the alarm code, description (LCD) and duration in days, hours, minutes and seconds.
Each screen is dedicated to a specic alarm. Use the and keys to move from one screen to the next.
Pressing the + keys simultaneously voids the alarms history.
2.4.2| Login
Menu: LOG – Login
Insert the 4-digit password that denes the level of access to the menus and parameters.
Press and to modify the value of the digit selected.
Press to conrm the value and move on to the next digit, if present, or to login.
The LEFT and RIGHT keys, if present, make it possible to move the cursor to the desired digit.
The passwords for access levels 1 through 3 are dened, respectively with parameters L01, L02 and L03.
LOGIN
GEN General Min Max Default U.M. Text value
pas Password
L01 Level 1 0 9999 0
L02 Level 2 0 9999 2000
L03 Level 3 0 9999 3000
Tab 4 _ [User interface - Menu-LOG - Login]
Note
*If you have not logged in, the
access level is 0. This level does not
let you display any parameters
and menus belonging to higher
access levels. The level for a given
menu and the parameters is
dened through the Congurator
software.“AHU_Interface_vNN.xls”.

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Air Handling seq. - user manual
2.4.3| Parameters
Menu: PAR - Parameters
Provides access to the parameters.
For a description of the parameters management submenus, (see chapter “15] Parameters”).
2.4.4| Displaying the input/output values
Menu: IO – Input/Output
Sub-menu: IOd – I/O Values
LED Display
The input and output values are displayed in sequence ( and ), indicating the input/output tags on display A
(“AI” for analog inputs; “AO” for analog outputs; “dI” for digital inputs and “dO” for digital outputs) while the value is
shown on display B (analog inputs which are not present or are in alarm mode are indicated with ----).
LCD Display
It is used to call up the three screens that display all inputs and outputs; each screen can display a group of 8 I/O. Use
the and keys to move from one screen to the next. The second and third screens are only for the MCX15 and
MCX20.
Fig 3 _ [Menu-based navigation - Displaying the input&output values]
Sub-menu: IOC – I/O Cong
If enabled through the Congurator software, makes it possible to access the input/output conguration screens.
For each input/output for the instrument, it is possible to set the type, work eld, polarity and function performed.