Desert Aire CM3550 Series User manual

Installation and Operation Manual
for GA, GS and GV Units
• Controls specific to
Controlled
Environment
Agriculture
• Monitoring of
temperature, RH,
dew point, and VPD
• Photocell input
allows for feedback
of light cycle
• Optional CO2
monitoring and
automated control
• Capability to link
units for coordinated
control in a single
space
• Cloud-based logging,
alarms, and control
when used with
AireGuard™

2

3
DANGER
ONLY TRAINED, QUALIFIED PERSONNEL SHOULD INSTALL AND/OR SERVICE
DESERT AIRE EQUIPMENT. SERIOUS INJURY, DEATH AND PROPERTY DAMAGE CAN
RESULT FROM IMPROPER INSTALLATION/SERVICE OF THIS EQUIPMENT. HIGH VOLTAGE
ELECTRICAL COMPONENTS AND REFRIGERANT UNDER PRESSURE ARE PRESENT.
Desert Aire
Dehumidication Equipment Standard Limited Warranty
Desert Aire warrants the dehumidifying unit to be free from defects in materials and workmanship subject to the terms,
conditions and limitations stated herein.
TERMS
Desert Aire warrants all components (except as noted) for a period of two (2) years from the date of shipment. This
warranty shall be limited to the supply of new or rebuilt parts for the part which has failed because of
defects in workmanship or material, and does not include the cost for labor, transportation or other costs not herein
provided for. Replaced parts are warranted only for the remaining portion of the original warranty period.
CONDITIONS
The warranty is subject to the following conditions:
1. The unit must be properly installed and maintained in accordance with the Desert Aire
“Installation and Operation Manual” provided with each unit and/or other documentation provided.
2. The Start-Up Report must be completed and returned to Desert Aire Service for evaluation. If no
deciencies are identied a Warranty Validation Letter will be issued that provides all warranty dates
and coverage. If installation or start-up deciencies are present, these must be corrected and
communicated to Desert Aire in order to activate warranty.
3. This warranty shall not apply to any part that has been tampered with, or has been subject to
misuse, negligence or accident. A warranty can be obtained for altered equipment but only with
written consent from Desert Aire.
 4. Thefollowingpartsandcomponentsareexcludedfromthewarranty:belts,lters,driers,fusesand
refrigerant.
5. Refrigerant coils or other components that corrode due to improperly balanced pool chemistry or
corrosive air quality will not be warranted.
6. All replacements or repairs will be FOB Germantown, WI.
7. This warranty shall be null and void if defects or damages result from unauthorized opening of the
refrigerant circuit, tampering with factory set controls, or operating outside the original design conditions.
8. Desert Aire shall not be liable for labor costs incurred in diagnosing the problem, or the removal
or replacement of the part or parts being repaired.
9. Desert Aire must preauthorize all warranty coverage described herein.
Desert Aire - CM3550 Manual

4
Extended Warranty:
Your Desert Aire unit may have extended warrantees beyond this Standard Limited Warranty document.
Extended warrantees are only available at the time of the purchase of the original equipment. These extended
warrantees are covered under a separate document and their terms and conditions are separate from this
document. It is mentioned in this document for informational purposes only. Any Extended Warranties will be
identiedontheWarrantyValidationletter.
Any and all incidental or consequential damages are expressly excluded from this warranty. Some states do not
allow the exclusion of incidental or consequential damages for personal injury, so the above limitations may not
apply to you for certain damages. This warranty gives you specic legal rights, and you may also have other
rights, which vary from state to state. No person or representative is authorized to make any warranty or assume
any liability not strictly in accordance with the aforementioned.
Inquiries regarding warranty matters should be addressed to:
Desert Aire Corp
c/o Service Manager
N120 W18485 Freistadt Road
Germantown, WI 53022
PH: [phone]
FAX: [phone]
E-MAIL: [email protected]
Additional copies of this manual can be purchased for a nominal fee from Desert Aire. Desert Aire also posts the most
current revision of our I/O Manuals on our website. For a digital copy of the I/O Manual for your unit revision, please
submit request to the contact information listed above.
Desert Aire - CM3550 Manual

5
Desert Aire - CM3550 Manual
Product Warning for the State of California

6Desert Aire - CM3550 Manual

7
TABLE OF CONTENTS
1. Installation ........................................................................................................................ 9
1.1. Introduction ............................................................................................................. 9
1.2. Sensor Installation .................................................................................................. 9
1.3. Auxiliary Air Heating Control Wiring ....................................................................... 9
1.3.1. Auxiliary Heating - Dry Contact Closure ...................................................... 9
1.3.2. Auxiliary Heating - Proportional Signal ........................................................ 10
1.4. CM3550 Controller Overview .................................................................................. 10
2. CM3550 Controller Details .............................................................................................. 11
2.1. Menu Overview and General Instructions .............................................................. 11
2.2. Zone Setpoints ....................................................................................................... 12
2.3. Main Menu .............................................................................................................. 13
2.3.1. Status Menu ................................................................................................. 14
2.3.1.1 Modes and Time ........................................................................... 14
2.3.1.2 I/O Status ..................................................................................... 15
2.3.1.2.1 Digital Inputs ................................................................ 15
2.3.1.2.2 Analog Inputs ................................................................ 17
2.3.1.2.3 Digital Outputs (Binary) ................................................ 19
2.3.1.2.4 Analog Outputs ............................................................. 20
2.3.1.2.5 pLAN Data .................................................................... 21
2.3.1.3 EXV/EMV Status .......................................................................... 22
2.3.2. Setback Menu ............................................................................................ 24
2.3.2.1 Schedule Options ......................................................................... 24
2.3.2.2 Current Schedule ......................................................................... 24
2.3.2.3 Temporary Holidays ..................................................................... 25
2.3.2.4 Annual Holidays ............................................................................ 26
2.3.2.5 Temporary Setback ....................................................................... 26
2.3.2.6 Set Time ....................................................................................... 27
2.3.3. Service Menu .......................................................................................... 27
2.3.3.1 Unit Setup ..................................................................................... 28
2.3.3.1.1 Intake Dew Point .......................................................... 28
2.3.3.1.2 Intake Air Temperature ................................................. 29
2.3.3.1.3 Timer Settings .............................................................. 30
2.3.3.1.4 Blower Setup ................................................................ 30
2.3.3.1.5 Remote Setpoints ......................................................... 33
2.3.3.2 Parameter Settings ...................................................................... 35
2.3.3.2.1 Reheat Settings ............................................................ 36
2.3.3.2.2 Aux Heat Settings ......................................................... 36
2.3.3.2.3 Ext Heat Settings .......................................................... 37
Desert Aire - CM3550 Manual

8
2.3.3.2.4 Zone Reset Settings ...................................................... 38
2.3.3.3 Sensor Offsets .............................................................................. 40
2.3.3.4 Pressure Cutouts .......................................................................... 41
2.3.3.5 CO2Setup ..................................................................................... 41
2.3.4. Unit Revision .............................................................................................. 43
3. Alarm Menu ..................................................................................................................... 45
3.1 Blower Motor Fault ................................................................................................. 45
3.2 Very Low Suction Pressure Alarm .......................................................................... 45
3.3 Low Suction Pressure Alarm .................................................................................. 46
3.4 High Discharge Pressure ....................................................................................... 46
3.5 Compressor OL ...................................................................................................... 46
3.6 Temperature Sensor Failure ................................................................................... 46
3.7 Low Voltage Monitor Tripped .................................................................................. 46
3.8 High Condensate Level .......................................................................................... 47
3.9 Smoke Alarm .......................................................................................................... 47
3.10 Low Air Flow Condition ........................................................................................... 47
3.11 Low Water Flow Condition ...................................................................................... 47
3.12 Freeze ‘Stat Alarm .................................................................................................. 47
3.13 Condenser Fan OL ................................................................................................. 47
3.14 Air Filter Service Required ...................................................................................... 47
3.15 ModBus Sensor Fault ............................................................................................. 48
3.16 Maximum / Minimum Zone Temperature / RH Alert ................................................ 48
3.17 Sensor Fault High / Low CO2.................................................................................. 48
3.18 Alarm History Screen .............................................................................................. 48
4. Hardware Details ........................................................................................................... 49
4.1. Programmable Controller ....................................................................................... 49
4.2. Suction Pressure Transducer .................................................................................. 49
4.3. Discharge and Liquid Pressure Transducer ............................................................. 49
4.4. Suction Line, Liquid and Supply Air Temperature Sensor ...................................... 50
4.5. Zone Air Temperature and Relative Humidity Sensor .................. ...... ...................... 50
4.6. Air Flow Proving Differential Pressure Sensor ....................................................... 50
5 Appendix ........................................................................................................................... 51
5.1 Remote Communication .......................................................................................... 51
5.1.1 BACnet Ethernet ........................................................................................ 51
5.1.2 BACnet MS/TP ........................................................................................... 54
Desert Aire - CM3550 Manual

9
1 Installation
1.1 Introduction
Your Desert Aire controller is designed for precise monitoring and control of air temperature, relative
humidity (RH) and Dew Point (DP) within a conditioned environment.
This CM3550 control system is easy to install and operate. The controller itself is installed in the
  electricalcabinetofthedehumidierandfeatureseitheraninternaldisplayterminal(IDT)oraremote
display terminal (RDT). This display allows viewing and adjustment of the unit’s sensors and set
  points.Italsoindicatestheoperatingstatusofmajorcomponentsinsidethedehumidier.
  Mostsensorsanddeviceshavebeenfactory-installedandwiredinsidethedehumidier.Inmost 
cases, only connection to a remote condenser, electrical power connection, zone and supply air
sensors are required. Connection to the facilities computer network or building management system
may also be required.
The CM3550 controller features optional building automation access. This includes options for
network communication ability including BACnet IP, BACnet MS/TP, ModBus RTU and ModBus IP.
1.2 Sensor Installation
The CM3550 control system requires a zone mounted combination relative humidity and temperature
sensor. Mount this sensor in the conditioned space away from any hot spots but in an area that is
  representativeofthezone.Constantairowacrossthissensorwillhelpinsureproperreadings.
A supply air temperature sensor is also required. Mount this sensor in the air duct supply conditioned
air to the zone.
1.3 Auxiliary Air Heating Control Wiring
Note: you must use the Desert Aire CM3550 control system to control or interlock with the room
  heatingsystem.Thispreventswideuctuationsinroomairtemperature.Italsopreventstheheater
  fromtryingtoheattheroomwhilethedehumidierisrunninginthecoolingmode.
1.3.1 Auxiliary Heating - Dry Contact Closure
The standard Desert Aire CM3550 Controller provides a dry contact closure to operate the
auxiliary space heater. The contact closes to energize a heater (may be supplied by others)
which has its own power source.
Install two wires from the thermostat blocks on the heater to the terminals H1 and H2 in the
   controlpanelofthedehumidier.Seeyourwiringschematicforconnectiondetails.
   Note:Unitswithaninternalelectricairheaterhaveanairowprovingswitchinstalled
between the heater and the control enclosure. If an air heater is installed external to the unit,
   provideanexternalairowprovingswitchforprotectionoftheheater.
Desert Aire - CM3550 Manual

10
1.3.2 Auxiliary Heating - Proportional Signal
Desert Aire will provide a proportional 0-10 VDC direct-acting signal to
modulate a heating coil control valve or other auxiliary modulating heater.
This signal may be changed to reverse acting. Contact Desert Aire’s service
department for help with this option.
   Mostproportionalvalveshaveeitherthree(3)orfour(4)terminalsforeld
installed wiring.
• Four-terminal valves have two terminals for 24 VAC power and two
terminals for the signal input.
• Three-terminal valves have one terminal for the “hot” 24 VAC input,
a second terminal for the “positive” signal input and a third, common
terminal for the “neutral” 24 VAC input and the “negative” signal
input.
You must follow the instructions included with any heating valve used.
Observe the proper polarity or you may damage both the valve and the
controller. See your wiring schematic for connection details.
1.4 CM3550 Controller Overview
  DesertAire’sCM3550microprocessorcontrollerisapowerful,exiblecontrollerwith
many useful features including:
• Display of zone air conditions and refrigerant pressures.
   •Displayofequipmentoperatingstatussuchasdehumidication,coolingand
heating.
• Display of alarms for abnormal conditions such as sensor failures or tripped
safety controls.
• Remote setpoint option as well as lights on and lights off setpoints.
• A convenient, easy-to-understand display interface which allows the
operator to view and change setpoints and time schedules.
Desert Aire - CM3550 Manual

11
2 CM3550 Controller Details
2.1 Menu Overview and General Instructions (Figure 1)
  YourDesertAirecontrollerispre-programmedandconguredatthefactoryforusein
  theapplicationyouhavespecied.Theinternaldisplayterminal(IDT,seeFigure1)
allows the operator to monitor and adjust the setpoints of your Desert Aire system.
The IDT has an LCD screen and six keys. These keys are labeled as below:
The remote display terminal (RDT) has an LCD screen and six keys. These keys are
labeled as below:
  TheHomeScreen(Figure1)displaystheDesertAirelogoandshowsthedehumidier
status, intake temperature and relative humidity and the operational state of the unit.
  Therightsideofthedisplayshows“Esc→Menu”whichindicatesthatiftheEsc key
is pressed, the Main Menu will be displayed. Pressing Esc on any other screen will
  takeyoubackonescreen.The“Prg→Stpt”indicatesthatifthePrg key is pressed,
  thesetpointscanbechanged.The“↑↓→Help”indicatesthatiftheUP or DOWN keys
are pressed, the help screens will be shown. The UP and DOWN keys will now scroll
through the help screens.
Menu screens allow the user to select from a series of actions. The action that is
capitalized on the screen is selected by pressing the ENTER key. To cycle through the
selections on a menu screen, use the UP and DOWN keys.
If setpoints or selections can be altered on a screen, the ENTER key will cycle through
those items. Once the cursor is over an item, the UP and DOWN arrow keys will
modify the setting. Numeric values require that the ENTER key be pressed to accept
Desert Aire - CM3550 Manual

12
the value. An “on” or “off” selection is altered as soon as the UP or DOWN keys are
pressed.
When an alarm is triggered, the red LED behind the ALARM key will light and will
remain on until the alarm is reset.
To view the alarms from any menu, simply press the ALARM key. If no alarm is active,
the display will state NO ALARMS. If an alarm is present, it will be displayed along
with the date and time it was triggered. The bottom two lines will display two data
points recorded when the alarm was triggered.
To reset the alarm, use the DOWN key until the reset instructions are shown. Pressing
the ALARM key for three seconds will reset all active alarms. See Section 3 for further
alarm and alarm data logging information.
Screens which display a small up arrow in the upper right and a small down arrow in
the lower right are part of a series of screens which can be accessed by pressing
either the UP or DOWN arrow keys. If the operator has not pressed a key for an hour,
the display will return to the Home Screen.
Figure 1
2.2 Zone Setpoints (Figure 2)
Pressing the Prg key from the Home Screen displays the ZONE SETPOINTS
  (Figure2).Thismenuallowsformodicationsofthetemperatureandhumidity
  setpointsspecictotheunitintheLightsOnorLightsOffmode.Tomodifythe
setpoints, press the ENTER key and use the arrow keys until the desired setting is
shown. Press the ENTER key to accept the setpoint value.
Desert Aire - CM3550 Manual

13
Figure 2
To return to the Home Screen, press the Esc key.
Pressing the DOWN key from the Zone Setpoints screen will display the Zone Alerts
screen shown in Figure 3. If the zone sensor readings fall below the Min settings or
rise above the Max settings, a Zone Alert will be triggered. Any alert will be recorded
as an alarm and will require the alarm to be reset. Alerts will not affect the operation
  ofthedehumidier.ThisalarmpointwillberecordedintheAlarmpoolcondenseris
  suppliedwiththedehumidier.
Figure 3
To return to the MAIN MENU, press the Esc key.
2.3 Main Menu (Figure 4)
Pressing the Esc key from the Home Screen displays the MAIN MENU (Figure 4).
This menu allows the operator to select the STATUS MENU, set an Occupancy
Schedule, enter the Service Menu and view the Unit Revision.
Desert Aire - CM3550 Manual

14
Figure 4
To return to the Home Screen, press the Esc key.
2.3.1 Status Menu (Figure 5)
Selecting the Status Menu will display the screen shown in Figure 5. The
Modes and Time may be selected as well as the status of the Analog and
Digital inputs and outputs and the electronic valve status.
Figure 5
2.3.1.1 Modes and Time (Figure 6)
Selecting MODES & TIME from the STATUS MENU displays a text
explanation of the unit. The Blower On or Off and the status of the
    SystemSwitchisshownontherstlineofthisdisplay.The
Compressor Off or the number of the compressors running and the
Lights On or Off is shown on the second line. The third line shows the
Unit Status, which will be one of the following states:
     •Off/Satised
• Heating Req.
• Cooling Req.
• Dehum Req.
• Dehum & Heat
• Dehum & Cool
• EXV Initialization
Desert Aire - CM3550 Manual

15
• Discharge Pressure Limiting
The fourth line will show any compressor that is required but delayed
due to its non-short cycling timer. The bottom line displays the date
and time.
Figure 6
To return to the STATUS MENU, press the Esc key.
2.3.1.2 I/O Status (Figure 7)
Selecting the I/O Status from the STATUS MENU displays Digital
Inputs, Analog Inputs, Digital Outputs, Analog Outputs and pLAN
Data selection menu. Use the UP or DOWN key to make a selection
and press the ENTER key.
Figure 7
To return to the STATUS MENU, press the Esc key.
2.3.1.2.1 Digital Inputs (Binary) (Figures 8-10)
Selecting the Digital Inputs Screen shows the state of the
     digitalcontactsusedbythecontrolsystem.Therstpage
     showsthestateoftherstveinputs.Thesescreensare
provided for troubleshooting the control system.
      •TherstlinewillshowthestatusofID1,thedigital 
Desert Aire - CM3550 Manual

16
setback input, “On” if the contact is closed, and “Off” if the contact is open.
• The second line will show the status of ID2, the supply blower
motor starter overload contacts, “OK” if no overload is present, and
“Flt” if an overload exists.
• The third line will show the status of ID3, compressor 1 motor
starter overload contacts, “OK” if no overload is present, and “Flt”
if an overload exists.
• The fourth line will show the status of ID4, compressor 2 motor
starter overload contacts, “OK” if no overload is present, and “Flt”
if an overload exists.
     •ThefthlinewillshowthestatusofID5,theVoltageMonitor,or
jumper, “OK” if the system voltage is stable, and “Flt” if the
system voltage is unstable.
Figure 8
The second page of the Digital Inputs shows the status of the next 5
contacts wired to the controller.
    •TherstlinewillshowthestatusofID6,thecondensatelevel
switch, or jumper, “OK” if the level is normal, and “Flt” if the level
is high.
    •ThesecondlinewillshowthestatusofID7,thewaterowswitch,
    “On”forowand“Off”fornoow.
• The third line will show the status of ID8, the Smoke
Alarm/General Fault Input, “OK” when the contact is closed and
“Flt” when the contact is open.
• The fourth line will show the status of ID9, the water coil t’stat,
“OK” if the contact is closed, and “Flt” if the contact is open.
    •ThefthlinewillshowthestatusoftheID10,thesystemswitch
“On” if the switch is on and “Off” if the switch is off.
Desert Aire - CM3550 Manual

17
Figure 9
The third page of the Digital Inputs shows the status of the last four
contacts wired to the controller.
    •TherstlinewillshowthestatusofID11,thephotocell,“On”if
there is no light, and “Off” if there is light.
• The second line will show the status of ID12, compressor 3 motor
starter overload contacts, “OK” if no overload is present, and “Flt” if
an overload exists.
• The third line will show the status of ID13, compressor 4 motor
starter overload contacts, “OK” if no overload is present, and “Flt”
if an overload exists.
    •ThefourthlinewillshowthestatusofID14,thelterswitch,“OK”
if the pressure drop is low, and “Flt” if the pressure drop is high.
Figure 10
The return to the I/O STATUS MENU, press the Esc key.
2.3.1.2.2 Analog Inputs (Figures 11-15)
Selecting the Analog Inputs Screens shows the state of the
      sensorsusedbythecontrolsystem.Therstpageshowsthe
suction and discharge pressure, the intake sensor RH and
Temperature readings as well as the supply air temperature
sensor.
Desert Aire - CM3550 Manual

18
Figure 11
The second page of Analog Inputs shows the readings of the
zone sensor RH and temperature readings; as well as the off
evaporator temperature and the differential air pressure drop
     forairowproving.
Figure 12
The third page of Analog Inputs shows the calculated dew
point readings of the intake and zone sensors.
Figure 13
The fourth page of Analog Input shows the suction pressure
and temperature. The suction P2T is also shown. The
superheat shown is a calculated value derived from the P2T
less the suction temperature.
Desert Aire - CM3550 Manual

19
Figure 14
     ThefthpageofAnalogInputsshowsthereadingsofthe
liquid pressure and temperature. The liquid P2T is also
shown. The subcooling shown is a calculated value derived
from the P2T less the liquid temperature.
Figure 15
To return to the I/O STATUS screen, press the Esc key.
2.3.1.2.3 Digital Outputs (Binary) (Figures 16 and 17)
The Digital Outputs screen shows the state of the devices
      turnedonandoffbythecontrolsystem.Therstpageshows
      thestateoftherst4relayoutputsofthecontroller.
      •TherstlinewillshowthestatusofCompressor1motor
starter, “On” and “Off”.
• The second line will show the status of Compressor 2
motor starter, “On” and “Off”.
• The third line will show the status of Compressor 3 motor
starter, “On” and “Off”.
• The fourth line will show the status of Compressor 4
motor starter, “On” and “Off”.
Desert Aire - CM3550 Manual

20
Figure 16
The second page shows the state of the last 4 outputs of the
controller.
     •TherstlinewillshowthestatusofAuxiliaryHeater,“On”
and “Off”.
• The second line will show the status of the Alarm
contact, “On” and “Off”.
• The third line will show the status of the Water Pump,
“On” and “Off”.
• The fourth line will show the status of the Supply Blower,
“On”, and “Off”.
Figure 17
To return to the I/O STATUS screen, press the Esc key.
2.3.1.2.4 Analog Outputs (Figure 18)
This screen is provided for troubleshooting the control system.
The Analog Outputs screen shows the following:
• Supply Air Speed Command
• Air Heat Modulating Command
Desert Aire - CM3550 Manual