Desert Aire CM3540 Series User manual

Installation and Operation Manual
for LW units
A
dvanced program
capabilities.
Internal Display
Te
rminal (IDT)
Multiple communication
interface options:
- LonW
orks®
- BACnet™ Ethernet
- BACnet™ MS/TP
- Modbus
®
Precise temperature
and humidity control.
CM3540 Series
Controller

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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.
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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]
TOLL FREE: [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.
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ProductWarningfortheStateofCalifornia
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     TABLEOFCONTENTS
1. Installation ........................................................................................................................ 9
1.1 Introduction ............................................................................................................. 9
1.2 Sensor Installation .................................................................................................. 9
1.2.1 Unit Mounted Sensor ................................................................................... 9
1.2.2 Wall-Mount Humidity and Temperature Sensor ........................................... 10
1.3 Auxiliary Air Heating Control Wiring ........................................................................ 10
1.3.1 Auxiliary Heating - Dry Contact Closure ....................................................... 10
1.3.2 Auxiliary Heating - Proportional Signal ......................................................... 10
1.4 CM3540 Controller Overview ................................................................................. 11
2. LW Controller Details .......................................................... ............................................. 13
2.1 Menu Overview and General Instructions
............................................................... 13
2.2 Zone Setpoints ........................................................................................................ 15
2.3 Main Menu ............................................................................................................. 15
2.3.1 Unit Status .................................................................................................... 16
2.3.2 ExV Status .................................................................................................... 16
2.3.3 Occupancy Schedule ................................................................................... 17
2.3.3.1 Time Settings ................................................................................ 18
2.3.3.2 Daily Events .................................................................................. 18
2.3.3.3 Vacation Periods ........................................................................... 19
2.3.3.4 Special Days ................................................................................. 20
2.3.3.5 Temporary Occupancy .................................................................. 20
2.3.4 Service Menu ................................................................................................ 21
2.3.4.1 Commissioning ............................................................................. 21
2.3.4.1.1 Conguration - Blower Setup ........................................ 22
2.3.4.1.2 Conguration - Condenser Setup ................................. 22
2.3.4.1.3 Airow Setup ................................................................. 24
2.3.4.1.4 Commissioning Tests .................................................... 25
2.3.4.1.5 Motor Phasing ............................................................... 27
2.3.4.1.6 BMS Setup .................................................................... 27
2.3.4.2 Tuning - Dead Bands .................................................................... 31
2.3.4.2.1 Tuning - Differentials ..................................................... 32
2.3.4.2.2 Tuning - Air Heating ...................................................... 33
2.3.4.2.3 Air Heating .................................................................... 33
2.3.4.3 I/O Status ...................................................................................... 34
2.3.4.3.1 Digital Inputs (Binary) ................................................... 34
2.3.4.3.2 Analog Inputs ................................................................ 35
2.3.4.3.3 Digital Outputs (Binary) ................................................ 36
2.3.4.3.4 Analog Outputs ............................................................. 38
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2.3.4.4 Sensor Offsets .............................................................................. 39
2.3.4.5 Diagnostics .................................................................................... 40
2.3.4.6 Memory Options ............................................................................ 41
2.3.5 Unit Revision ................................................................................................. 43
3. Alarm Menu ........................................................................................................................... 45
3.1 Too many mem writings or Retain mem write error ................................................ 46
3.2 Low Suction Pr. ....................................................................................................... 46
3.3 Discharge Pr. .......................................................................................................... 46
3.4 Compressor Overload ............................................................................................. 47
3.5 Modbus Sensor Fault .............................................................................................. 47
3.6 Blower Overload ..................................................................................................... 47
3.7 Smoke Alarm ........................................................................................................... 47
3.8 c.pCOe Comm Fault ............................................................................................... 47
3.9 c.pCOe Cnfg Fault .................................................................................................. 47
3.10 Alarm Log ................................................................................................................ 47
4. Hardware Details .............................................................................................................. 49
4.1 Programmable Controller ........................................................................................ 49
4.2 Suction Pressure Transducer ................................................................................. 49
4.3 Discharge Pressure Transducer ............................................................................ 49
4.4 Suction Line, Liquid & DHU Temperature Sensor ................................................... 50
4.5 Zone Air Temperature and Relative Humidity Sensor ............................................ 50
4.6 Reheat Condenser and Evaporator Bypass Differential Air Pressure Sensors ...... 50
5. Appendix ............................................................................................................................ 51
5.1 Internal Web Page .................................................................................................. 51
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1. Installation
1.1 Introduction
Your Desert Aire CM3540 controller is designed for precise monitoring and control of air
temperature and relative humidity (RH) within a conditioned environment.
This CM3540 control system is easy to install and operate. The controller features an
internal display terminal (IDT). This display allows viewing and adjustment of the unit’s
sensors and set points. It also indicates the operating status of major components inside
of the dehumidier. The CM3540 controller also has the ability to control auxiliary equipment
such as a customer supplied exhaust blower, outdoor air damper, and auxiliary heating
devices for optimum energy efciency.
Most sensors and inputs have been factory-installed and wired inside of the dehumidier.
In most cases, only connection to a remote condenser, electrical power connection and an
Ethernet connection to the facilities computer network are required. An additional sensor,
included in the control assembly, needs to be mounted in the return air duct or the zone
to be conditioned. This device senses the conditioned zone air temperature and relative
humidity to control the LW dehumidier. Also, units with surface temperature sensors will
require additional wiring.
The control system includes a web page which allows a virtual display terminal to be
accessed from any device on the computer network. Simply browse to the IP address
assigned to the dehumidier, enter the appropriate credentials,
[user - Desert-Aire, password - 18485] and select the DISPLAY tab. Logging is also available
from this web page.
The CM3540 controller also features optional building automation access. This includes
options for network connect ability including LONWORKS, BACnet IP, BACnet MS/TP,
ModBus RTU and ModBus IP.
1.2 Sensor Installation
The CM3540 control system is normally provided with a unit mounted combination relative
humidity and temperature sensor. This sensor provides accurate control without the problems
associated with wall mounted sensors, such as faulty readings due to hot spots or drafts.
1.2.1 Unit Mounted Sensor
This sensor is factory mounted in the return air duct upstream of any outdoor air
intakes.
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 1.2.2 Wall-MountHumidityandTemperatureSensor
If our dehumidier was ordered with a wall-mount humidity and temperature sensor,
mount the sensor about ve feet above oor, on an interior wall with natural air
circulation. Avoid the following locations:
• Hot spots near concealed heating pipes, warm air ducts, supply register
outlets, or solar radiation.
• Cold spots due to a cold wall or draft from stairwells, doors, windows, or
supply register outlets.
• Dead spots such as behind doors or in corners where room air cannot
circulate freely
Install using 24-16 AWG stranded wire; 18 AWG stranded wire recommended.
Do not run sensor wiring adjacent to, OR in the same conduit as, wires carrying more
than 24 VAC. See manufacturer’s specications for more details.
1.3 AuxiliaryAirHeatingControlWiring
Note: You must use the Desert Aire CM3540 control system to control or interlock with the
room heating system. This prevents the heater from trying to heat the room while the
dehumidier is running in cooling mode.
 1.3.1 AuxiliaryHeating-DryContactClosure
The standard Desert Aire CM3540 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 terminal 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.
 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. 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 “neutral” 24 VAC input and the “negative” signal
input.
The control signal may also be set for reverse-acting or for 2-10 VDC. Contact
Desert Aire Service Department for recommendations or instructions on how these
options can be implemented.
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1.4 CM3540 Controller Overview
Desert Aire’s CM3540 microprocessor controller is a powerful, exible controller with many
useful features including:
• Display of room air temperature, relative humidity and refrigerant pressures.
• Display of equipment operating status such as dehumidication and cooling.
• Display of alarms for abnormal conditions such as sensor failures or tripped
safety controls.
• An optional seven-day occupancy timer which can control outdoor air dampers
(if used) to bring in fresh air when the dehumidier is in an occupied state.
• A convenient, easy-to-understand display interface which allows the operator to
view and change set points and time schedules.
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2. LWControllerDetails(Figure1)
Figure 1
2.1 MenuOverviewandGeneralInstructions(Figures2and3)
Your Desert Aire CM3540 Controller is pre-programmed and congured at the factory for use in the
application specied. The internal display (IDT – Figure 1) allows the operator to monitor the operation
and adjust the set points of your Desert Aire LW dehumidier.
The IDT has an LCD screen and six keys. The keys from left to right are:
Figure 2
The Home Screen (Figure 2) displays the Desert Aire logo and shows the dehumidier status, zone
temperature and relative humidity, it also shows the operational state of the fan, compressor and air
heating. The unit type and tonnage is displayed in the upper right of the screen. Below this line,
“Esc → Menu” 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.
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The “Prg → Stpt” indicates that if the Prg key is pressed, the set points can be changed.
The “↑ ↓ → Help” indicates that if the UP or DOWN keys are pressed, the help screens will be
shown. The UP or DOWN keys will now scroll through the help screens.
Figure 3
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 or DOWN keys.
If set points 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 the value. An “on” or “off”
selection will be 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 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 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 terminal display will return to
the Home Screen.
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2.2 ZoneSetpoints(Figure4)
Pressing the Prg key from the Home Screen displays the ZONE SETPOINTS (Figure 4).
This menu allows for modications of the temperature and humidity set points specic to the
unit. To modify set points, press the ENTER key and use the arrows until the desired setting
is shown. Press the ENTER key to accept the set point value. To return to the Home Screen,
press the Esc key.
Figure 4
2.3 MainMenu(Figure5)
Pressing the Esc key from the Home Screen displays the MAIN MENU (Figure 5). This menu
allows the operator to view the Unit Status screens, set the Occupancy Schedule, enter the
Service Menu, and view the Unit Revision.
To return to the Home Screen, press the Esc key.
Figure 5
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 2.3.1UnitStatus(Figure6)
Selecting Unit Status from the MAIN MENU displays a text explanation of the unit.
On the rst line of this screen if a remote condenser is available, the screen displays
“RC Available”. If no remote condenser is available, the screen displays “RC
Unavailable”. The Occupied state (either Occupied or Un-Occupied) is shown on the
second line along with the state of the blower. The Unit Status will show one of the
following states on the third line.
• Zone Satised
• Heating Req
• Cooling Req
• Dehum Req
• Dehum/Heat
• Dehum/Cool
• Low Airow
• Defrost Cycle
• Low R/A Temp
• ExV Init
• Surface Dehum
The fourth line will display if the compressor is on or off. The fth line will indicate if
the compressor is waiting for its no-short cycling timer to time out and the time left
before a restart is available. The very bottom of this screen is the current time and
date set in the unit controller.
To return to the MAIN MENU, press the Esc key.
Figure 6
 2.3.2ExVStatus(Figure7)
Pressing the DOWN key from the UNIT STATUS screen displays a text/numerical
explanation of the unit’s refrigeration system. On the rst line of this screen the
Superheat and Sub-Cooling values are displayed. In the lower right corner of the
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screen the following values are displayed from top to bottom; Suction Pressure,
Suction Temperature and Evaporation Temperature. In the lower left corner of
the screen the following is displayed from top to bottom; Valve Steps, Valve % Open,
Valve Status and Valve Emergency Controls Status.
The Valve Status can be one of the three values:
• “---“ – Value is not initialized (Unit Size not set)
• “On” – Value is operating
• “Off” – Value is Standby
The Valve Controls Status can be one of the four values:
• “Low SH” – Low Superheat Controls
• “LOP” – Low Operating Pressure Controls
• “MOP” – High Operating Pressure Controls
• “Hi TCond” – High Condensing Temperature Controls
To return to the MAIN MENU, press the Esc key.
Figure 7
 2.3.3OccupancySchedule(Figure8)
Select the OCCUPANCY SCHEDULE from the MAIN MENU to enable a schedule to
place the dehumidier in the occupied mode. See Figure 7. To enable a schedule
select Yes, and press ENTER. The schedule will need to be setup before this will be
enabled. Pressing the Prg key from this menu allows the date and time to be modied.
To return to the MAIN MENU, press the Esc key.
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Figure 8
   2.3.3.1TimeSettings(Figure9)
This screen set the time, date and day of week. To modify these
settings press the ENTER key until the cursor is over the appropriate
item and use the arrow keys until the desired setting is shown. All
times are set in the 24 hour format. Pressing the ENTER key will
accept that value and step to the next item. At the bottom of this
screen the time zone can be selected and set from listed options.
To return to the OCCUPANCY SCHEDULE, press the Esc key.
Figure 9
   2.3.3.2DailyEvents(Figure10)
This is where each day’s events are set. Four settings are possible,
which will allow two separate occupancy periods. Check the rst box
by pressing the UP key when the cursor is over the check box. Set the
time in 24 hour format and then select ‘Occupied’ or ‘Un-Occupied’.
Save this date at the bottom of this screen by selecting ‘Yes’ and
pressing ENTER.
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Once a day is entered these settings can be copied on any other
day by selecting a day to copy, setting the Copy To: the
appropriate day, and then selecting Ok? to ‘Yes’. Modify these days as
appropriate.
To return to the OCCUPANCY SCHEDULE MENU, press the Esc key.
Figure 10
   2.3.3.3VacationPeriods(Figure11)
The Vacation Periods will allow three sets of vacation to keep the
dehumidier ‘Occupied’ or ‘Un-Occupied’. Set the range of days that
this will occur, the Start Date and the End Date for that holiday.
To return to the OCCUPANCY SCHEDULE MENU, press the Esc key.
Figure 11
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  2.3.3.4SpecialDays(Figure12)
Also available are 6 special days where the full day can be set for
either ‘Occupied’ or ‘Un-Occupied’.
To return to the OCCUPANCY SCHEDULE MENU, press the Esc key.
Figure 12
  2.3.3.5TemporaryOccupancy(Figure13)
This screen allows the unit to be manually set to Occupied for a preset
amount of time. Press the ENTER key and enter the hours you would like the
unit to be temporarily in the occupied mode. Press the ENTER key again and
enter the minutes you would like the unit to be in the temporarily occupied
mode. Press the ENTER key again and the cursor will begin blinking over the
‘Set Override’ message. Press the UP and ENTER keys to set this override to
‘On’. The dehumidier will now be ‘Occupied’ for this period of time. When the
override expires, the screen will again display Set Override, and the
dehumidier will return to its normal state.
To return to the OCCUPANCY SCHEDULE MENU, press the Esc key.
Figure 13
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