McQuay MicroTech III RDS, MicroTech III RFS, MicroTech III RCS, MicroTech III RPS, MicroTech III RDT Operation And Maintenance Manual
...
Operation and Maintenance Manual OM 920-1
MicroTech® III Unit Controller for Applied
Rooftop and Self-Contained Systems
RAH, RCS, RDS, RDT, RFS, RPS, SWP, and SWT
Group: Applied Systems
Part Number: OM 920-1
Date: October 2009
© 2009 McQuay International
Contents
Introduction .............................................................. 4
Getting Started ................................................... 5
Using the Keypad/Display ....................................... 6
Passwords.......................................................... 7
Navigation Mode ................................................ 8
Edit Mode ........................................................... 8
Service Timers ................................................... 8
Rapid Start ......................................................... 8
Manual Control ................................................... 9
Keypad/Display Menu Structure ........................... 10
System Summary Menu ................................... 12
Standard Menus ............................................... 14
System Menu ................................................... 15
Occupancy Menu ............................................. 17
Temperature Menu........................................... 18
Flow Summary Menu ....................................... 19
Supply Fan Speed Menu.................................. 20
Return/Exhaust Fan Speed Menu .................... 20
Cooling Menu ................................................... 21
Head Pressure Menu ....................................... 22
Evap Condensing Menu ................................... 23
Economizer Menu ............................................ 24
Min OA Damper Menu...................................... 24
Heating Menu ................................................... 26
Energy Recovery.............................................. 27
Dehumidification Menu..................................... 28
Daily Schedule Menu ....................................... 29
One Event Schedule Menu .............................. 29
Holiday Schedule Menu ................................... 29
Optimal Start Menu .......................................... 29
Operating Hours Menu ..................................... 30
Extended Menus .............................................. 31
Unit Setup Menu............................................... 31
Timer Settings Menu ........................................ 32
Time/Date Menu............................................... 33
Supply Fan Setup Menu................................... 33
Return/Exhaust Fan Setup Menu ..................... 34
Zone Temperature Setup Menu ....................... 35
Compressor Setup Menu ................................. 36
Head Pressure Setup Menu ............................. 37
Chilled Water Setup Menu ............................... 37
Economizer Setup Menu .................................. 38
Design Flow Setup Menu ................................. 39
Heating Setup Menu......................................... 40
Dehumidification Setup Menu .......................... 41
Alarm Out Configuration Setup Menu .............. 42
Alarm Limits Setup Menu ................................. 43
Manual Control Menu ....................................... 43
Active Alarm Menu ........................................... 46
Alarm Log Menu ............................................... 46
Advanced Menus.............................................. 47
Unit Configuration Setup Menu ........................ 47
Save/Restore Menu.......................................... 49
LON/BACnetIP/BACnetMSTP Setup Menu ...... 50
Alarm Delays Setup Menu ................................ 50
Analog Input Status Menu................................. 50
Universal I/O Status Menu ................................ 51
Digital Input Status Menu.................................. 52
Digital Output Status Menu ............................... 52
Adv Setup Settings Menu ................................. 54
Adv Status Parameters Menu ........................... 55
Alarms...................................................................... 56
Alarm Clearing .................................................. 56
Warnings........................................................... 56
Problems........................................................... 57
Faults ................................................................ 60
Operator’s Guide .................................................... 62
Determining Unit State...................................... 63
Off Operating State ........................................... 63
Start Up Operating State................................... 64
Recirculating Operating State ........................... 64
Heating.............................................................. 65
Economizer ....................................................... 65
Mechanical Cooling........................................... 65
Determining Unit Status .................................... 66
Determining Control Mode ................................ 66
Determining Cooling Status .............................. 67
Determining Heat Status................................... 68
Determining Economizer Status ....................... 68
Determining Cooling Capacity .......................... 69
Determining Heating Capacity .......................... 69
Determining Supply Air Fan Capacity ............... 69
Determining RF/EF Capacity ............................ 69
Determining Outside Air Damper Position ........ 70
Determining Emergency Mode ......................... 70
Determining Application Mode .......................... 70
Determining Occupancy Status ........................ 71
Determining Occupancy Mode.......................... 72
Determining Occupancy Source ....................... 72
Unoccupied Operation ...................................... 73
Scheduling ........................................................ 73
Temperature Control Configurations................. 75
Heat/Cool Changeover ..................................... 75
Dehumidification ............................................... 78
Energy Recovery .............................................. 80
Outside Air Damper Control.............................. 84
Outside Air Damper Control, Two Position ....... 86
Special Procedures for Units with WRV and More
Than Two Circuits. ............................................ 90
Water Pump Control ......................................... 91
Cooling: Multistage ........................................... 91
Cooling: Modulating ........................................ 105
Heating Control ............................................... 110
Modulating ...................................................... 111
Min DAT .......................................................... 112
Indoor Air Fan - On/Off Control....................... 117
Introduction
Introduction
This manual provides information regarding the MicroTech III control system. It specifically
describes the operation and programmable options for units with constant air volume (CAV)
control and variable air volume (VAV) control.
The MicroTech III Controller is a self contained device that is capable of complete, standalone operation. Information in the controller can be displayed and modified by using the
keypad/display in the units main control panel. For installation and startup instructions and
general information regarding a particular unit, refer to the applicable model-specific
installation and maintenance manual.
For installation and startup instructions and general information regarding a particular rooftop
unit, refer to the applicable model-specific installation and maintenance manual (Table 1).
Table 1: Installation and Maintenance Resources
Unit Manual
MicroTech III Rooftop Unit Controller - BACnet IP
Communications
MicroTech III Rooftop Unit Controller - BACnet
MSTP Communications
MicroTech III Rooftop Unit Controller - BACnet
LON Communications
MicroTech III Unit Controller IM 919
RPS/RDT/RFS/RCS 015C-105C IM 926
RPS/RDT/RFS/RCS 050D-140D IM 893
SWP Self-Contained (018 to 105) IM 937
IM 916
IM 917
IM 918
NOTICE
This equipment generates, uses, and can radiate radio frequency energy, and
if not installed and used in accordance with this instruction manual, may cause
interference to radio communications. It has been tested and found to comply
with the limits for a Class A digital device, pursuant to part 15 of the FCC rules.
These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment.
Operation of this equipment in a residential area is likely to cause harmful
interference in which case the user is required to correct the interference at his
own expense. McQuay International disclaims any liability resulting from
any interference or for the correction thereof.
WARNING
Electric shock hazard. Can cause personal injury or equipment damage.
This equipment must be properly grounded. Connections and service to the
MicroTech II control panel must be performed only by personnel that are
knowledgeable in the operation of the equipment being controlled.
4 McQuay OM 920-1
Introduction
WARNING
Excessive moisture in the control panel can cause hazardous working
conditions and improper equipment operation.
When servicing this equipment during rainy weather, the electrical
components in the main control panel must be protected from the rain.
CAUTION
Extreme temperature hazard. Can cause damage to system components.
The MicroTech III controller is designed to operate in ambient temperatures
from -20°F to 125°F. It can be stored in ambient temperatures from -40°F to
140°F. It is designed to be stored and operated in relative humidity up to 95%
(non-condensing).
CAUTION
Static sensitive components. A static discharge while handling
electronic circuit boards can cause damage to the components.
Discharge any static electrical charge by touching the bare metal inside the
main control panel before performing any service work. Never unplug any
cables, circuit board terminal blocks, relay modules, or power plugs while
power is applied to the panel.
Getting Started
This manual contains information designed to assist the field technician with unit setup. The
technician will need to be familiar with the following topics at a minimum to successfully set
up unit operation.
• Keypad navigation/editing/passwords
• Control Mode
• Occ Mode
• DSP Setpoint
• BSP Setpoint
• Heat/Cool Changeover (Zone Setpoints)
• DAT Clg Setpoint
• DAT Htg Setpoint
• Clg Enable (OAT/EWT lockout)
• Htg Enable (OAT lockout)
• Econo Enable (Changeover temp/Enthalpy switch)
• Ventilation Limit/OA damper
McQuay OM 920-1 5
Using the Keypad/Display
3/23
System Summary
Advanced Menus
Alarm Lists
Unit State= Cooling
Clg Capacity=
25%
Using the Keypad/Display
The keypad/display consists of a 5-line by 22 character display, three keys and a “push and
roll” navigation wheel. There is an Alarm Button, Menu (Home) Button, and a Back Button.
The wheel is used to navigate between lines on a screen (page) and to increase and decrease
changeable values when editing. Pushing the wheel acts as an Enter Button.
Figure 1: Keypad Controls
The first line on each page includes the page title and the line number to which the cursor is
currently “pointing”. The line numbers are X/Y to indicate line number X of a total of Y lines
for that page. The left most position of the title line includes an “up” arrow to indicate there
are pages “above” the currently displayed items, a “down” arrow to indicate there are pages
“below” the currently displayed items or an “up/down” arrow to indicate there are pages
“above and below” the currently displayed page.
Each line on a page can contain status only information or include changeable data fields.
When a line contains status only information and the cursor is on that line all but the value
field of that line is highlighted meaning the text is white with a black box around it. When the
line contains a changeable value and the cursor is at that line, the entire line is highlighted.
Each line on a page may also be defined as a “jump” line, meaning pushing the navigation
wheel will cause a “jump” to a new page. An arrow is displayed to the far right of the line to
indicate it is a “jump” line and the entire line is highlighted when the cursor is on that line.
The keypad/display Information is organized into five main menus or menus groups; Alarm
Lists Menu, System Summary Menu, Standard Menus, Extended Menus and Advance Menus.
Note – Only menus and items that are applicable to the specific unit configuration are displayed.
The Alarm Lists Menu includes active alarm and alarm log information. The System
Summary Menu includes status information indicating the current operating condition of the
unit. Standard Menus include basic menus and items required to setup the unit for general
operation. These include such things are control mode, occupancy mode and heating and
cooling setpoints. Extended Menus include more advanced items for “tuning” unit operation
such as PI loop parameters and time delays. Advanced Menus include the most advanced
items such as “unit configuration” parameters and service related parameters. These generally
do not needing changing or accessing unless there is a fundamental change to or a problem
with the unit operation.
6 McQuay OM 920-1
Using the Keypad/Display
1/3McQuay AHU
Enter Password
Continue W/O Password
Version Information
1/1
Enter Password
Enter Password
***
*
Passwords
When the keypad/display is first accessed, the Home Key is pressed, the Back Key is pressed
multiple times, or if the keypad/display has been idle for the Password Timeout timer (default
10 minutes), the display will show a “main” page where the user can enter a password or
continue without entering a password. The three password levels available are Level 2, Level
4, and Level 6, with Level 2 having the highest level of access. Entering the Level 6 password
allows access to the Alarm Lists Menu, System Summary Menu, and the Standard Menus
group. Entering the Level 4 password allows similar access to Level 6 with the addition of the
Extended Menus group. Entering the Level 2 password allows similar access to Level 4 with
the addition of the Advanced Menus group. The Level 2 password is 6363, the Level 4 is
2526, and the Level 6 password is 5321. Continuing without entering one of these three levels
allows access only to the Alarm Lists Menu and the System Summary Menu.
Note – Alarms can be acknowledged without entering a password.
Figure 2: Password Main Page
The password field initially has a value **** where each * represents an adjustable field.
These values can be changed by entering the Edit Mode described below.
Figure 3: Password Entry Page
Entering an invalid password has the same effect as continuing without entering a password.
Once a valid password has been entered, the controller allows further changes and access
without requiring the user to enter a password until either the password timer expires or a
different password is entered. The default value for this password timer is 10 minutes. It is
changeable from 3 to 30 minutes via the Timer Settings menu in the Extended Menus.
McQuay OM 920-1 7
Using the Keypad/Display
Navigation Mode
In the Navigation Mode, when a line on a page contains no editable fields all but the value
field of that line is highlighted meaning the text is white with a black box around it. When the
line contains an editable value field the entire line is inverted when the cursor is pointing to
that line.
When the navigation wheel is turned clockwise, the cursor moves to the next line (down) on
the page. When the wheel is turned counter-clockwise the cursor moves to the previous line
(up) on the page. The faster the wheel is turned the faster the cursor moves.
When the Back Button is pressed the display reverts back to the previously displayed page. If
the Back button is repeated pressed the display continues to revert one page back along the
current navigation path until the “main menu” is reached.
When the Menu (Home) Button is pressed the display reverts to the “main page.”
When the Alarm Button is depressed, the Alarm Lists menu is displayed.
Edit Mode
The Editing Mode is entered by pressing the navigation wheel while the cursor is pointing to a
line containing an editable field. Once in the edit mode pressing the wheel again causes the
editable field to be highlighted. Turning the wheel clockwise while the editable field is
highlighted causes the value to be increased. Turning the wheel counter-clockwise while the
editable field is highlighted causes the value to be decreased. The faster the wheel is turned the
faster the value is increased or decreased. Pressing the wheel again cause the new value to be
saved and the keypad/display to leave the edit mode and return to the navigation mode.
Service Timers
A user may override timers for a period of up to 240 minutes by setting the Service Timer to a
non-zero number. When the Service Timer is not zero, the times listed below are set to the
Service Time (Default = 20 seconds) instead of the normal values. This allows the unit to be
run through its operating states without having to wait for the normal time delays to expire.
These times revert to the standard values when the Service Time count down to zero or is set
to zero by the user.
The affected times are:
• Cooling Stage Time
• Heating Stage Time
• Start Initial Time
• Recirculation
• ZeroOATime
Rapid Start
The user may elect to initiate a rapid startup sequence at unit power up by setting the Rapid
Start flag to Yes. When this flag is set to Yes, the Service Timer is set to 10 minutes whenever
the power is reset to the controller.
8 McQuay OM 920-1
Using the Keypad/Display
Manual Control
A user may manually control outputs to check operation of components when Manual Control
is set to ManCtrl. When Manual Control is set to ManCtrl, the unit is disabled and the unit is
shut down in the normal manner if it is operating. Outputs listed in the Manual Control menu
of the Keypad/Display section can then be controlled directly until Manual Control is set to
Normal.
Note – Manual Control will be set to No automatically after 240 minutes so that a person could not
When Manual Control is set to Yes, the Control Mode is set to Off so that the unit will not
restart automatically.
When Manual Control is set to Normal all digital outputs in the Manual Control menu are set
to Off and all the analog outputs are set to 0.0% so that all outputs are in the Off or minimum
position when Manual Control is set to ManCtrl.
All alarms except those listed below are overridden during Manual Control.
During manual control, the unit will respond in the normal manner to the following alarms.
• Emergency Stop Fault
• Duct High Limit
• High Return Temperature
• High Discharge Temperature
• Low Discharge Temperature
• High Pressure - Circuit # 1
• High Pressure - Circuit # 2
• Low Pressure - Circuit # 1
• Low Pressure - Circuit # 2
put the unit into Manual Mode control and walk away from the unit and let it run at the
manual settings.
McQuay OM 920-1 9
Keypad/Display Menu Structure
Keypad/Display Menu Structure
The following is a description of the MicroTech III menu structure. These menus and items
can all be displayed with the keypad/display. Menu items displayed will change based on the
selected unit configuration. Keypad/display menus are divided into 1) System Summary
menu - password required. 2) Standard menu - password not required. 3) Extended Menu higher level password required. 4) Advanced Menu - requires the highest level password.
Figure 4: Keypad/Display Menu Structure
10 McQuay OM 920-1
Keypad/Display Menu Structure
McQuay OM 920-1 11
Keypad/Display Menu Structure
System Summary Menu
Menus in the System Summary category contain basic unit operating status and control set
point parameters. The items shown in the System Summary Menu are Read Only and are not
adjustable from this menu. The following are brief descriptions of the System Summary
category menus and items. No password is required to view the System Summary Menu.
Table 2: System Summary Menu
Menu Display Name
Unit State= - Off None
Clg Capacity= - 0-100% None
OAD/Econo Cap= - 0-100% None
Htg Capacity= - 0-100% None
Reheat Cap= - 0-100% None
Control Temp= - -50.0-200.0°F None
Zone Clg Spt= - 0.0-100.0°F None
Zone Htg Spt= - 0.0-100.0°F None
Disch Air= - -50.0-250.0°F None
DAT Clg Spt= - 40.0-100.0°F None
DAT Htg Spt= - 40.0-140.0°F None
Min DAT Limit= - 0.0-70.0°F None
SAF Speed= - 0-100% None
DSP - 0.2-4.0in None
DuctSP Spt= - 0.2-4.0in None
RF/EF Speed= - 0-100% None
BSP - -0.25-0.25in None
BldgSP Spt= - -0.25-0.25in None
OA Temp= - -50.0-200.0°F None
EW Temp= - -50.0-150.0°F None
Rel Humidity= - 0-100% None
Default
Setting
Range
Star t
Recirc
FanOnly
MinDAT
Htg
Econo
Clg
Password
Level
Unit State is a status only item which indicates the state of operation in which the unit is
currently operating. The unit can be in any of the operating states shown.
Clg Capacity is a status only item which indicates the percentage of the unit maximum
cooling capacity currently operating.
OAD/Econo Cap is a status only item which indicates the percentage that the outdoor damper
or economizer valve is currently open.
Htg Capacity is a status only item which indicates the percentage of the unit maximum
heating capacity currently operating.
Reheat Cap is a status only item which indicates the percentage of the unit maximum reheat
capacity currently operating.
Control Temp is a status only item which displays the current value of the “Control
Temperature.” The “Control Temperature” is defined as the temperature input selected by the
Control Temperature Source parameter. For example, if the Control Temperature Source
parameter is set to “Return,” then the Control Temperature parameter reads the same value as
the Return Air parameter.
Zone Clg Spt is a status only item which indicates the temperature in which the unit will go
into the cooling mode of operation.
Zone Htg Spt is a status only item which indicates the temperature in which the unit will go
into the heating mode of operation.
12 McQuay OM 920-1
Keypad/Display Menu Structure
Disch Air is a status only item which displays the current temperature reading from the unit's
discharge air temperature sensor (DAT). This sensor is standard on all units.
DAT Clg Spt is a status only item which indicates the temperature that the DAT should be
maintained at when it is in the cooling mode of operation.
DAT Htg Spt is a status only item which indicates the temperature that the DAT should be
maintained at when in the heating mode of operation.
Min DAT Limit is a status only item which indicates the discharge air low limit temperature
on CAV zone control units. Heating will be activated to maintain this setting when the
discharge temperature falls below it during the Fan Only operating state. On VAV or CAV
discharge control units, the minimum discharge temperature limit is the DAT Clg Spt.
SAFSpeed is a status only item which indicates the capacity of the supply air fan.
DSP is a status only item which displays the current duct static pressure reading.
DuctSP Spt= is a status only item which indicates the duct static pressure set point used for
controlling the VFD for the supply air fan. The VFD is modulated to maintain the duct
pressure at this value.
RF/EF Speed is a status only item indicating the capacity of the return fan/exhaust air fans.
BSP is a status only item which displays the current building static pressure reading.
BldgSP Spt is a status only item which indicates the building static pressure set point used for
controlling the return/exhaust fan VFD. The return/exhaust fan VFD is modulated to maintain
the building static pressure sensor input to this value.
OA Temp is a status only item which displays the current temperature reading from the unit
mounted outdoor air temperature sensor. This sensor is standard on all units.
EW Temp is a status only item that displays the current temperature reading from the unit
mounted entering water temperature sensor. The sensor is standard on all water-cooled units.
Rel Humidity is a status only item that displays the current relative humidity reading from the
optional humidity sensor.
McQuay OM 920-1 13
Keypad/Display Menu Structure
Standard Menus
The Standard Menus are menu items that control the unit's day to day operation. The menus
provide information about the units operation and its control parameters. Accessing the
Standard Menus requires the operator to enter the four-digit level 6 password, (5321) using the
keypad buttons located on the controller interface.
Table 3: Standard Menus
Menu Display Name Item Display Name Default Setting Range Password Level
Standard Menu System 6
RF/EF Spd Control 6
Evap Condensing 6
One Event Schedule 6
Holiday Schedule 6
Occupancy 6
Temperatures 6
Flow Summary 6
SAF Spd Control 6
Cooling 6
Head Pressure 6
Economizer 6
Min OA Damper 6
Heating 6
Energy Recovery 6
Dehumidification 6
Daily Schedule 6
Optimal Start 6
Operating Hours 6
14 McQuay OM 920-1
Keypad/Display Menu Structure
System Menu
The “System” menu provides a summary of basic unit status and control items. This menu
summarizes the current operating state of the unit, giving the operating state the unit is in,
along with the current capacity level of that operating state.
Table 4: System Menu
Menu Display Name Item Display Name Default Setting Range Password Level
System Unit State = - Off 6
Star t
Recirc
FanOnly
MinDAT
Htg
Econo
Clg
Unit Status = - Enable 6
OffMan
OffMnCtl
OffNet
OffAlm
OffFnRty
Dehum Status= - Inactive 6
Active
Ctrl Mode = Off Off 6
HeatOnly
CoolOnly
FanOnly
HeatCool
Auto
Clg Status = - Enabled 6
None
OffAmb
OffAlarm
OffNet
OffMan
Htg Status = - Enabled 6
None
OffAmb
OffAlarm
OffNet
OffMan
Econo Status = - Enabled 6
None
OffAmb
OffAlarm
OffNet
OffMan
OffDehum
Clg Capacity= - 0-100% 6
Htg Capacity= - 0-100% 6
Reheat Cap= - 0-100% 6
SAF Speed = - 0-100% 6
RF/EF Speed = - 0-100% 6
OAD/Econo Cap= - 0-100% 6
Rel Humidity= - 0-100% 6
Emerg Mode= Normal Normal 6
Off
Net App Mode= Auto Off 6
HeatOnly
CoolOnly
FanOnly
Auto
McQuay OM 920-1 15
Keypad/Display Menu Structure
Unit State is a status only item which indicates the state of operation in which the unit is
currently operating.
Unit Status is a status only item which indicates the current operating status.
Dehum Status is a status only item which indicates whether or not Dehumidification is
currently active.
Ctrl Mode is an adjustable item which allows the unit to be set for off, auto heating/cooling
operation, cooling only, heating only, and fan only.
Clg Status is a status only item which indicates whether or not mechanical cooling is currently
allowed. If cooling is disabled, the reason is indicated.
Htg Status is a status only item which indicates whether or not heating is currently allowed. If
heating is disabled, the reason is indicated.
Econo Status is a status only item which indicates whether or not the economizer is currently
enabled. If economizer is enabled, the reason is indicated.
Clg Capacity is a status only item which indicates the percentage of the unit maximum
cooling capacity currently operating.
Htg Capacity is a status only item which indicates the percentage of the unit maximum
heating capacity currently operating.
Reheat Cap is a status only item which indicates the percentage of the unit maximum reheat
capacity currently operating.
SAF Speed is a status only item which indicates the current speed of the supply air fan.
RF/EF Speed is a status only item which indicates the current speed of the return fan/exhaust
air fans.
OAD/Econo Cap is a status only item which indicates the percentage that the outdoor
damper/waterside economizer valve is currently open.
Rel Humidity is a status only item that displays the current relative humidity reading from the
optional humidity sensor.
Emerg Mode is an adjustable item which indicates if the unit was shut down in an emergency
situation via a network command.
Net App Mode is a network adjustable item which indicates that the unit is set for network
off, cooling only, heating only, fan only or auto heating/cooling operation via a network signal.
This item has no affect on the unit operation unless the Ctrl Mode item is set to “Auto.”
16 McQuay OM 920-1
Keypad/Display Menu Structure
Occupancy Menu
Menus in the Occupancy menu contain status and control items that relate to unit
occupied/unoccupied operation.
Table 5: Occupancy Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Occupancy Occupancy= Occ 6
Unocc
TntOvrd
Occ Mode= Auto Occ 6
Unocc
TntOvrd
Auto
OccSrc= - None 6
NetSchd
IntSchd
OneEvnt
RemoteSw
OccManCmd
OccMode
TStatTO
ManTO
UnoccSrc= - UnoccDehum 6
UnoccClg
UnoccHtg
IntOptStrt
NetOptStrt
None
Tnt Ovrde Time= 0 0-300min 6
Occupancy is a status only item which indicates whether the unit is currently in an occupied,
unoccupied, or tenant override mode of operation.
OccMode is an adjustable item which allows the unit to be set for manual occupied or
unoccupied operation, automatic operation based on a time schedule input or manual bypass
operation.
OccSrc is a status only item which indicates the input source or function that is responsible for
setting the Occupancy parameter to “Occ.”
UnoccSrc is a status only item which indicates the input source or function that is responsible
for setting the Occupancy parameter to “Unocc.”
Tnt Ovrd Time is an adjustable item which indicates the amount of time remaining for unit
operation since tenant override operation was activated.
McQuay OM 920-1 17
Keypad/Display Menu Structure
Temperature Menu
Menus in the Temperatures menu contain unit temperature status information.
Table 6: Temperature Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Temperatures Control Temp= - -50.0-200.0°F 6
Control Temp is a status only item which indicates what the current control temperature is.
Disch Air is a status only item which displays the current temperature reading from the unit's
discharge air temperature sensor (DAT). This sensor is standard on all units.
Return Air is a status only item which displays the current temperature reading from the
unit's return air temperature sensor (RAT). This sensor is standard on all units.
Space Temp is a status only item which displays the current space (or zone) temperature
reading from the optional unit space air temperature sensor input. If an optional space
temperature sensor is not installed, the SpaceT Present= item in the Setup menu should be set
to “No” to disable the alarm function associated with an open circuit at the space temperature
sensor input.
OA Temp is a status only item which displays the current temperature reading from the unit
mounted outdoor air temperature sensor. This sensor is standard on all units.
Disch Air= - -50.0-250.0°F 6
Return Air= - -20.0-200.0°F 6
Space Temp= - -0.0-150.0°F 6
OA Temp= - -50.0-200.0°F 6
EFT/LC Temp= - -50.0-250.0°F 6
EW Temp= - -50.0-150.0°F 6
Mixed Air= - -50.0-250.0°F 6
EFT/LCT (RTU) is a status only item which displays the current entering fan/leaving coil
temperature reading from the unit mounted temperature sensor. This sensor is available on
RTU units with dehumidification capability. This sensor is also installed on units equipped
with either gas or electric heat and is used by the controller to calculate the heat rise across the
heat exchanger by comparing it to the discharge air temperature input. The controller uses this
information to protect the heat exchanger against overheating.
EWT (SCU) is a status only item that displays the current temperature reading from the unit
mounted entering water temperature sensor. The sensor is standard on all water-cooled units.
MAT (SCU) is a status only item that displays the current temperature reading from the unit
mounted mixed air temperature sensor. The sensor is standard on all Self Contained units.
18 McQuay OM 920-1
Keypad/Display Menu Structure
Flow Summary Menu
Table 7: Flow Summary Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Flow Summary Airflow = - NoFlow 6
Flow
Waterfl ow= - NoFlow 6
Flow
Water Pump= - Off 6
On
Supply Fan= - Off 6
On
Ret/Exh Fan= - Off 6
On
FanOp= - Off 6
On
Airflow is a status only item that indicates whether or not discharge airflow is detected.
Airflow status is sensed by a binary input delivered to the controller by a differential pressure
switch (PC7). On VAV units duct static pressure is also a factor in the indication of airflow.
Waterflow is a status only item that indicates whether or not water flow is detected. Water
flow status is sensed by a binary input delivered to the controller by an optional water flow
sensor (WF1).
Water pump is a status only item that indicates whether or not the Pump Start Output is
active. The pump start output is available for field use to start a field supplied pump when
water flow is required. For field wiring requirements for using this output refer to “Field
Wiring” in the MicroTech III Installation Manual (IM 919). The Pump Start Output is turned
on whenever the economizer bypass valve is open, the unit is in the Econo or Cooling
operating state, economizer flush mode is active or a Freeze fault or Freeze problem alarm is
active or has been active within the past 10 minutes. Otherwise the Pump Start Output is off.
Supply Fan is a status only item which indicates whether or not the controller is commanding
the unit supply fan on.
Ret/Exh Fan is a status only item which indicates whether or not the controller is
commanding the unit RF/EF fan on.
FanOp is a status only item which indicates whether this output (MCB DO10) is On or Off.
McQuay OM 920-1 19
Keypad/Display Menu Structure
Supply Fan Speed Menu
Table 8: Supply Fan Speed Menu
Menu Display Name Item Display Name Default Setting Range Password Level
SAF Spd Control SAF Speed= - 0-100% 6
SAF Speed is a status only item that indicates the current supply fan speed.
Speed Cmd is a status only item that indicates the current supply fan VFD commanded speed.
Duct Press is a status only item which indicates the current pressure of the supply air
ductwork. The duct pressure is measured at the location in which the duct static pressure tap
was field installed. This device is not factory installed.
DuctSP SPT is an adjustable item which sets the duct static pressure set point used for
controlling the VFD for the supply air fan. The VFD is modulated to maintain the duct
pressure at this value.
SAF Ctrl is an adjustable parameter used to select how the supply fan is to be controlled. The
supply fan can be controlled by supply air fan by duct pressure or by a percentage of supply
air fan speed from 25% to 100%. The speed option is typically used with a building
automation system.
Speed Cmd= - 0-100% 6
Duct Press= - 0.0-5.0in 6
DuctSP Spt= 1.0in 0.2-4.0in 6
SAF Ctrl= DSP DSP 6
Speed
Rem SAF Cap= 25% 0-100% 6
Remote SF Cap is an adjustable item for setting the supply fan speed by the keypad or by a
network control signal.
Return/Exhaust Fan Speed Menu
Table 9: Return/Exhaust Fan Speed Menu
Menu Display Name Item Display Name Default Setting Range Password Level
RF/EF Spd Control RF/EF Speed= - 0-100% 6
Speed Cmd= - 0-100% 6
Min Speed = 5% 0-100% 6
Bldg Press= - -0.25-0.25in 6
BldgSP Spt= 0.050in -0.25-0.25in 6
RF/EF Ctrl= Tracking None 6
Tracking
BldgP
Speed
Rem RAF Cap= 5% 0-100% 6
Rem ExhF Cap= 5% 0-100% 6
RF/EF Speed a status only item that indicates the current return/exhaust fan VFD speed.
Speed Cmd is a status only item that indicates the current return/exhaust fan VFD
commanded speed.
Min Speed is a status only item that indicates the minimum return/exhaust fan VFD speed.
Bldg Press is a status only item which indicates the building static pressure at the building
static pressure sensor location.
BldgSP Spt is an adjustable item which sets the building static pressure set point used for
controlling the VFD for the return/exhaust air fan. The VFD is modulated to maintain the
building pressure at this value.
RF/EF CP Ctrl is an adjustable parameter used to select how the return/exhaust fans are to be
controlled. The exhaust fans can be controlled by the building pressure or by a percentage of
return/exhaust air fan speed from 25% to 100%. The speed option is typically used with a
building automation system.
20 McQuay OM 920-1
Keypad/Display Menu Structure
Remote RAF Cap is an adjustable item for setting the return fan speed by the keypad or by a
network control signal.
Remote EF Cap is an adjustable item for setting the exhaust fan speed by the keypad or by a
network control signal.
Cooling Menu
Table 10: Cooling Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Cooling Zone Clg Spt= 72.0°F 0.0-100.0°F 6
Unocc Clg Spt= 85.0°F 40.0-100.0°F 6
DAT Clg Spt= 55.0°F 40.0-100.0°F 6
Clg Reset= - None 6
- Ntwrk
- Space
- Return
-OAT
- ExtmA
- ExtV
None Airflow
Min Clg Spt= 55.0°F 40.0-100.0°F 6
Min Clg Spt @ 0/ 0-100/ 6
NA NA
- °F
-°C
- mA
- %
Max Clg Spt= 65.0°F 40.0-100.0°F 6
Max Clg Spt @ 100/ 0-100/ 6
NA NA
- °F
- °C
-mA
- %
Zone Clg Spt an adjustable item which sets the temperature in which the unit will go into the
cooling mode of operation.
Unocc Clg Spt is an adjustable item which sets the zone temperature at which the unit starts
up and provides unoccupied cooling (night setup) during unoccupied periods.
Note – Setting this to its minimum value will disable unoccupied cooling.
DAT Clg Spt is an adjustable item used by the controller to set the DAT cooling setpoint. This
value is adjustable only when it is not being set by a reset schedule.
Clg Reset is an adjustable item used to set the type of cooling reset to be used.
Min Clg Spt is an adjustable item which sets the minimum cooling discharge set point for use
with a cooling discharge air temperature set point reset schedule.
Min Clg Spt @ is an adjustable item which sets the value of the sensor input, selected with
the Cooling Reset parameter, at which the DAT cooling setpoint parameter is reset to the
minimum DAT cooling setpoint value.
Max Clg Spt is an adjustable item which sets the maximum cooling discharge set point for
use with a cooling discharge air temperature set point reset schedule.
Max Clg Spt @ is an adjustable item which sets the value of the sensor input, selected with
the Cooling Reset parameter, at which the DAT cooling setpoint parameter is reset to the
maximum DAT cooling setpoint value.
McQuay OM 920-1 21
Keypad/Display Menu Structure
Figure 5 graphically shows the cooling reset operation. Example, The normal DAT cooling
setpoint is 55.0 F. The cooling reset scheme is set to airflow. The unit is to adjust the DAT
from 55.0 F to 65.0 F. When the unit is at 35% of the design airflow the discharge temperature
is to be 65.0 F. When the unit is at 80% of its airflow the DAT is to be 55.0F. This example
would give the following inputs:
Min Clg Spt = 55.0 F
Min Clg Spt @ = 80%
Max Clg Spt = 65.0 F
Max Clg Spt @ = 35%
Based on the above, the unit will have a discharge air temperature setpoint of 55.0 F from 80%
to 100% of the airflow.
Figure 5: Cooling Setpoint
Head Pressure Menu
The Head Pressure menu contains parameters that are used to maintain head pressure control.
Table 11: Head Pressure Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Head Pressure WRV Pos= - 0-100% 6
Head P Circ 1= - 0-750psi 6
Head P Circ 2= - 0-750psi 6
Setpoint= 260psi 230-340psi 6
WRV Pos is a status only item that indicates the current water regulating valve position.
Head P Circ 1 is a status only item that indicates the current refrigerant pressure for circuit
#1.
Head P Circ 2 is a status only item that indicates the current refrigerant pressure for circuit
#2.
Setpoint is an adjustable item that sets the refrigerant setpoint used for controlling the water
regulating valve. The water-regulating valve is modulated to maintain the refrigerant pressure.
Note – This section only applies to Self Contained units with a water regulating valve.
22 McQuay OM 920-1
Keypad/Display Menu Structure
Evap Condensing Menu
Table 12: Evap Condensing Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Evap Condensing Cond Fan Spd= - 0-100% 6
CFan Spd Cmd= - 0-100% 6
Min Fan Speed= 25% 0-100% 6
Stage Time= 10min 0-100min 6
Sump Temp= - -50.0-150.0°F 6
Min Sump T= 75.0°F 0.0-100.0°F 6
Max Sump T= 85.0°F 0.0-100.0°F 6
Sump Dump Spt= 3-5.0°F 0.0-100.0°F 6
Pump Status= - Off 6
On
Smp Pmp Delay= 30s 0-300s 6
Conductivity= - 0-5000S/cm 6
Dophin System= No No 6
Yes
Cond Fan Speed is a status only item that displays the current VFD speed when the
evaporative condenser option includes a VFD to control the first condenser fan on each circuit.
Cond Fan Spd Cmd is a status only item that indicates the current Condenser fan VFD
commanded speed.
Min Fan Speed is an adjustable item used to set the minimum speed for the VFD speed when
the evaporative condenser option includes a VFD to control the first condenser fan on each
circuit.
Stage Time is an adjustable item used to set a minimum time period between condenser fan
stage changes.
Sump Temp is a status only item that displays the current evaporative condenser sump
temperature.
Min Sump T is an adjustable item used to set a minimum evaporative condenser sump
temperature set point. This value is used to determine when condenser fans are turned off.
Max Sump T is an adjustable item used to set a maximum evaporative condenser sump
temperature set point. This value is used to determine when condenser fans should be turned
on.
Sump Dump Spt is an adjustable item used to set a minimum sump temperature. The sump is
emptied to prevent freezing if the sump temperature drops below this set point.
Sump Pump Status is a status only item that displays the current evaporative condenser sump
pump status.
Smp Pmp Delay adjustable item used to set the amount of time the sump pump fail alarm is
delayed. If the Sump Pump status remains Off after the Sump Pump Output has been turned on
for more than the Sump Pump Delay time, a Sump Pump fail alarm is initiated.
Conductivity is a status only item that displays the conductivity level of the water in the sump
of an evaporative cooled condenser on rooftop units.
Dolphin System is an adjustable parameter that indicates to the controller whether or not a
Dolphin water treatment method is being used. When set to “yes” the controller assures the
sump pump is run every three days to reduce scaling.
McQuay OM 920-1 23
Keypad/Display Menu Structure
Economizer Menu
Table 13: Economizer Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Economizer Economizer Pos= - 0-100% 6
Economizer Pos is a status only item that is used to indicate percentage that the economizer
dampers/waterside economizer valve is open.
DAT Clg Spt is an adjustable item used by the controller to set the DAT cooling setpoint. This
value is adjustable only when it is not being set by a reset schedule.
Min OA Pos is a status only item which indicates the current minimum position of the
outdoor air damper.
Chgover Temp is an adjustable item which sets the OA dry bulb temperature at which the
units changes over to the economizer operation.
EWT Diff is an adjustable item that sets a differential below the MAT at which waterside
economizer operation is enabled based on entering water temperature.
Min OA Damper Menu
DAT Clg Spt= 55.0°F 40.0-100.0°F 6
Min OA Pos= - 0-100% 6
Chgover Temp= 55.0°F 0.0-100.0°F 6
EWT Diff= 3.0d°F 0.0-10.0°F 6
Table 14: Min OA Damper Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Min OA Damper Min OA Pos= - 0-100% 6
Vent Li mit= 20% 0-100% 6
DCV Limit= 10% 0-100% 6
Min OA Reset= None None 6
Network
Ext VDC
Ext mA
IAQ VDC
IAQ mA
DesignFlow= Yes No 6
Yes
OA @ MinV/mA= 0% 0-100% 6
OA @ MaxV/mA= 100% 0-100% 6
Min V/mA= 0.0/V 0.0-20.0/V/mA 6
Max V/mA= 10.0/V 0.0-20.0/V/mA 6
PPM @DCV Lmt= 800ppm 0-5000ppm 6
PPM @Vnt Lmt= 1000ppm 0-5000ppm 6
PPM= - 0-5000ppm 6
Min PPM= 0ppm 0-5000ppm 6
Max PPM= 2000ppm 0-5000ppm 6
V/A @Min PPM= 0.0/V 0.0-20.0/V/mA 6
V/A @Max PPM= 10.0/V 0.0-20.0/V/mA 6
Min Fan Diff= 20% 0-100% 6
Max Fan Diff= 50% 0-100% 6
OA Flow= - 0-60000CFM 6
MinOAFlw Spt= 2000CFM 0-60000CFM 6
Min Clg Spd= 40% 0-100% 6
LoFlo V Lmt= 30% 0-100% 6
Min OA Pos is a status only item which indicates the current minimum position of the
outdoor damper. This value does not go above a value called the Ventilation Limit and does
not go below a value called the Demand Control Ventilation Limit.
24 McQuay OM 920-1
Keypad/Display Menu Structure
On CAV units the Ventilation Limit and the Demand Control Ventilation Limit are fixed
values set equal to the Vent Limit= and DCV Limit= parameters. On VAV units the OA
Damper Position increases from the Vent Limit= value to the LoFloVent Limit= value as the
VFD speed goes from 100% down to the Min Clg Spd= value. The Demand Control
Ventilation Limit in this VAV case is determined by the Ventilation Limit X DVC Limit=/Vent
Limit=. When the Min OA Reset= parameter is set to “None” the Min OA Pos= value is set to
the Ventilation Limit. If Min OA Reset= is set to Network, Ext VDC, Ext mA, IAQ VDC, or
IAQ mA, the Min OA Pos= varies between the Ventilation Limit and the Demand Control
Ventilation Limit as the reset signal varies from its maximum to minimum value.
Vent L i mit is an adjustable item that sets the value of the Ventilation Limit on a CAV unit or
when a VAV unit is at 100% discharge fan speed.
DCV Limit is an adjustable item that sets the value of the Demand Control Ventilation Limit
on a CAV unit or when a VAV unit is at 100% discharge fan speed. This item is only used
when the “Min OA Reset=” is set to something other than “None.”
Min OA Reset is an adjustable item that sets the type of minimum OA damper position reset
to be used. When this is set to “None” the Min OA Pos= parameter is set to the Ventilation
Limit. When this is set to “Network,” “Ext VDC,” “Ext mA,” “IAQ VDC,” or “IAQ mA” then
the Min OA Pos= parameter varies from the Ventilation Limit down to the Demand Control
Ventilation Limit as the reset signal goes from its maximum to minimum value.
Design Flow is an adjustable item used to turn the optional DesignFlow outdoor airflow
measuring reset function on and off. This is one of several available methods of automatically
resetting the Min OA Pos parameter.
OA @ MinV/mA is is an adjustable item used when Min OA Reset is set to “Ext VDC” or
“Ext mA” to define at what percent of the field input signal the Min OA Pos is to be at the
Demand Control Ventilation Limit value.
OA @ MaxV/mA is an adjustable item used when Min OA Reset= is set to “Ext VDC” or
“Ext mA” to define at what percent of the field input signal the Min OA Pos= is to be at the
Ventilation Limit value.
Min V/mA is an adjustable item used to set the minimum value of the field input signal.
Max V/mA is an adjustable item used to set the maximum value of the field input signal.
PPM @ DCV Limit is an adjustable item used when Min OA Reset= is set to “IAQ VDC” or
“IAQ mA” to define at what PPM value the Min OA Pos= is to be at the Demand Control
Ventilation Limit value.
PPM @ Vent Limit is an adjustable item used when Min OA Reset= is set to “IAQ VDC” or
“IAQ mA” to define at what PPM value the Min OA Pos= is to be at the Ventilation Limit
value.
PPM is a status only item which indicates the current reading from the CO2 sensor.
Min PPM is an adjustable item that sets the minimum PPM value.
Max PPM is an adjustable item that sets the maximum PPM value.
V/mA @ Min PPM is an adjustable item that sets the minimum PPM value and the minimum
DC voltage or mA value of the CO
sensor used when Min OA Reset= is set to “IAQ VDC” or
2
“IAQ mA.”
V/mA @ Max PPM is an adjustable item that sets the maximum PPM value and the
maximum DC voltage or mA value of the CO
“IAQ VDC” or “IAQ mA.”
Min Fan Diff is an adjustable item which sets a differential between the discharge and return
fan capacities above which the minimum allowable Min OA Position begins to be reset
upwards from the Demand Control Ventilation Limit toward the Ventilation Limit.
McQuay OM 920-1 25
sensor used when Min OA Reset= is set to
2
Keypad/Display Menu Structure
Max Fan Diff is an adjustable item which sets a differential between the discharge and return
fan capacities at which the minimum allowable Min OA Position is fully reset up to the
Ventilation Limit.
OA Flow is a status only item which indicates the current outdoor airflow based on an
optional OA airflow sensor input used when the unit is equipped the DesignFlow OA control
feature.
Min OAFlw Spt is an adjustable item that is used to set the minimum design flow CFM's
when the unit is equipped with the optional DesignFlow OA control feature.
Min Clg Spd is an adjustable item that sets the discharge fan speed on a VAV unit at which the
Ventilation Limit reaches the LoFloVent= value.
LoFlo Vent Limit is an adjustable item that sets the maximum value for the Ventilation Limit
on a VAV unit.
Heating Menu
The Heating menu provides a summary of the control parameters for units with heating. The
unit's heating mode of operation is controlled by the control temperature and the heating
setpoint temperature. The unit goes into the heating mode of operation by analyzing the
control temperature. The control temperature can be return temperature, space temperature or
outside air temperature. The unit goes into the heating mode of operation when the control
temperature is below the heating setpoint by more than ½ the deadband.
Table 15: Heating Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Heating Zone Htg Spt= 68.0°F 0.0-100.0°F 6
Unocc Htg Spt= 55.0°F 40.0-100.0°F 6
MWUSpt= 70.0°F 40.0-100.0°F 6
DAT Htg Spt= 100.0°F 40.0-140.0°F 6
Htg Reset= None None 6
Ntwrk
Spac e
Return
OAT
ExtmA
ExtV
Min Htg Spt= 55.0°F 40.0-140.0°F 6
Min Htg Spt @ 0/ 0-100/ 6
NA NA
°F
°C
mA
Max Htg Spt= 55.0°F 40.0-140.0°F 6
Max Htg Spt @ 0/ 0-100/ 6
NA NA
°F
°C
mA
Min DAT Ctrl= Yes Yes/No 6
Min DAT Limit= 55.0°F 0.0-70.0°F 6
Occ Heating= Ye s No 6
Yes
Zone Htg Spt is an adjustable item which sets the control temperature at which the unit will
go into the heating mode of operation.
Unocc Htg Spt is an adjustable item which sets the zone temperature at which the unit starts
up and provides unoccupied heating (night setback) during unoccupied periods.
MWUSpt is an adjustable item which sets the heating setpoint to be used during morning
warm up on a discharge temperature control unit.
26 McQuay OM 920-1
Keypad/Display Menu Structure
DAT Htg Spt is an adjustable parameter which sets the heating discharge set point.
Htg Reset is an adjustable item used to set the type of heating reset to be used.
Min Htg Spt is an adjustable item which sets the minimum heating discharge set point for use
with a heating discharge air temperature set point reset schedule.
Min Htg Spt @ is an adjustable item which sets the value of the sensor input, selected with
the heating reset parameter, at which the heating setpoint is reset to the Min Htg Spt value.
Max Htg Spt is an adjustable item which sets the maximum heating discharge set point for
use with a heating discharge air temperature set point reset schedule.
Max Htg Spt @ is an adjustable item which sets the value of the sensor input, selected with
the heating reset parameter, at which the heating setpoint is reset to the Max Htg Spt value.
Min DAT Ctrl is an adjustable item used to activate or deactivate the low discharge
temperature limit function available on units equipped with modulating or multistage heat.
Min DAT Limit is a status only item which indicates the discharge air low limit temperature
on CAV zone control units. Heating will be activated to maintain this setting when the
discharge temperature falls below it during the Fan Only operating state. On VAV or CAV
discharge control units, the minimum discharge temperature limit is the DAT Clg Spt.
Occ Heating is an adjustable item which enables and disables the “daytime” heating mode of
operation. If the Occ Heating parameter is set to No, the unit will only go into heating during
the initial morning warm-up cycle. If the Occ Heating parameter is set to Yes, the unit can go
into the heating mode of operation any time during the day.
Energy Recovery
The Energy Recovery menu contains parameters that relate to or are used to control the
enthalpy wheel and exhaust fan when a unit is equipped with an optional energy recovery
wheel system.
Table 16: Energy Recovery
Menu Display Name Item Display Name Default Setting Range Password Level
Energy Recovery Energy Rec= Ye s No 6
Yes
Wheel Speed= - 0-100% 6
Whl Spd Cmd= - 0-100% 6
ER DAT= - -50.0-200.0°F 6
ER ExhT= - -50.0-200.0°F 6
Min ExhT Diff= 2.0°F 1.0-10.0°F 6
Max ExhT Diff= 6.0°F 1.0-10.0°F 6
Stage Time= 5min 1-100min 6
Min Off Time= 20min 1-100min 6
Rel Humidity= - 0-100% 6
Min Whl Spd= 33% 0-100% 6
Energy Rvcy is an adjustable item which turns the optional energy recovery system on /off.
Wheel Speed a status only item that indicates the energy wheel VFD speed.
Wheel Spd Cmd is a status only item that indicates the current energy wheel VFD
commanded speed.
ER DAT is status only item which displays the current discharge air temperature leaving the
optional energy recovery wheel.
ER Exh T is status only item which displays the current exhaust air temperature leaving the
optional energy recovery wheel. Note: This sensor is present only when the unit is equipped
with the energy recovery wheel frost protection option
Min Exh T Diff is an adjustable item that sets a differential below the calculated potential
energy recovery exhaust air frosting point. When the ER Exh T falls below the calculated
McQuay OM 920-1 27
Keypad/Display Menu Structure
frosting point by more that this value the energy wheel will be driven to its minimum speed to
prevent frosting.
Max Exh T Diff is an adjustable item that sets a differential above the calculated potential
energy recovery exhaust air frosting point. Once the wheel is drive to minimum speed to
prevent frosting it driven back to maximum speed only when ER Exh T rises back above the
calculated frosting point by more that this value.
Stage Time is an adjustable item used to set a minimum time period for operating at either the
minimum or maximum speed before action is taken to change speed during the frost protect
mode of operation.
Min Off Time is an adjustable item used to set the minimum amount of time the energy wheel
will remain off after being turned off due to a frosting/condensation condition.
Rel Humidity is a status only item that indicates the current relative humidity reading of the
sensor.
Min Whl Spd is an adjustable item that sets the minimum energy wheel VFD speed.
Dehumidification Menu
Table 17: Dehumidification Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Dehumidification Dehum Status= - Disabled 6
Enabled
Rel Humidity= - 0-100% 6
Dewpoint= - -50-150°F 6
Dehum Method= None None 6
Rel Hum
DewPt
RH Setpoint= 50% 0-100% 6
Dewpoint Spt= 50°F 0-100°F 6
Reheat Spt= - 40.0-100.0°F 6
Reheat Cap = - 0-100% 6
Dehum Status is a status only item that indicates whether dehumidification is enabled or
disabled.
Rel Humidity is a status only item that indicates the current sensor relative humidity reading.
DewPoint is a status only item that indicates the current value that is calculated by the
controller using the Rel Humidity value and either the Space Temp or Return Air value,
depending on the setting of the Humidity Sensor Location. This parameter can either be set to
“Space” or “Return.”
Dehum Method is an adjustable item used to set the dehumidification method to either “RH”
or “DewPt.” When this parameter is set to “RH,” dehumidification operation is controlled to
maintain the Rel Humidity value at the Relative Humidity Set Point. When this parameter is
set to “DewPt,” dehumidification operation is controlled to maintain the Dew Point= value at
the Dew Point Set Point.
RH Setpoint is an adjustable item used to set the relative humidity value at which the relative
humidity will be controlled to during dehumidification operation.
Dewpoint Spt is an adjustable item used to set the Dewpoint value at which the dewpoint with
will be controlled to during dehumidification operation.
Reheat Spt is a status only item which is used to indicate the DAT temperature to which the
HGRH valve will be controlled to in the Cooling and Fan Only operating states while
dehumidification operation is active. The Reheat Setpoint equals the DAT Cooling Setpoint
for DAT controlled units and will vary in between the minimum and maximum reheat setpoint
for Zone Controlled units.
Reheat Cap is a status only item that indicates the current reheat capacity value.
28 McQuay OM 920-1
Keypad/Display Menu Structure
Daily Schedule Menu
The Daily Schedule sets the start and stop times for each of the days of the week. One start and
one stop time can be set for each day.
Table 18: Daily Schedule Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Daily Schedule Mon= 00:00 – 00:00 00:00 – 23:59 6
Tue= 00:00 – 00:00 00:00 – 23:59 6
Wed= 00:00 – 00:00 00:00 – 23:59 6
Thu= 00:00 – 00:00 00:00 – 23:59 6
Fri= 00:00 – 00:00 00:00 – 23:59 6
Sat= 00:00 – 00:00 00:00 – 23:59 6
Sun= 00:00 – 00:00 00:00 – 23:59 6
Hol= 00:00 – 00:00 00:00 – 23:59 6
One Event Schedule Menu
The One Event Schedule is used to set the start and stop times for one event.
Table 19: One Event Schedule Menu
Menu Display Name Item Display Name Default Setting Range Password Level
One Event Schedule Beg= 00/00/00 @ 00:00 00/00/00-12/31/99
@ 00:00 – 23:59
End= 00/00/00 @ 00:00 00/00/00-12/31/99
@ 00:00 – 23:59
6
6
Holiday Schedule Menu
The Holiday Schedule is used to set the start and stop times for up to 16 different holidays.
Table 20: Holiday Schedule Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Holiday Schedule Hol 1= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 2= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 3= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 4= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 5= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 6= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 7= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 8= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 9= 00/00/00-00/00/00 00/00/00-12/31/99 6
Hol 10= 00/00/00-00/00/00 00/00/00-12/31/99 6
Optimal Start Menu
The Optimal Start menu is used to set up the unit so it starts at the most efficient time before
building occupancy.
Note – Even though these parameters are adjustable, other than perhaps the Design Htg OAT
Table 21: Optimal Start Menu
Enable is an adjustable item that turns on the optimal start feature. Setting the value to yes
will activate this function.
and the Design Clg OAT they generally do not require adjustment as they will be
automatically adjusted during normal optimal start operation.
Menu Display Name Item Display Name Default Setting Range Password Level
Optimal Start Enable= No No 6
Yes
Htg Rate= 0.4°F/min 0.0-1.0°F/min 6
Htg OAT= 35°F -40-60°F 6
Des Htg OAT= 0°F -40-60°F 6
Clg Rate= 0.4°F/min 0.0-1.0°F/min 6
Clg OAT= 85°F -60-140°F 6
Des Clg OAT= 95°F -60-140°F 6
McQuay OM 920-1 29
Keypad/Display Menu Structure
Htg Rate is an adjustable item that sets the rate of temperature rise in degrees per minute
when the unit was last started optimally in heating.
Htg OAT is an adjustable item that sets the outdoor air temperature when the unit was last
started optimally in heating.
Design Htg OAT is an adjustable item that sets the outdoor air temperature at which the
heating system could just hold the load. The rate of temperature rise would equal zero.
Clg Rate is an adjustable item that sets the rate of temperature drop in degrees per minute
when the unit last started optimally in cooling.
Clg OAT is an adjustable item that sets the outdoor air temperature when the unit was last
started optimally in cooling.
Design Clg OAT is an adjustable item that sets the outdoor air temperature at which the
cooling system could just hold the load. Rate of temperature rise would equal zero.
Operating Hours Menu
The Operating Hours menu gives a summary of the hours of operation for each of the supply
fans, return/exhaust fans, compressors, heating and economizer operation.
Table 22: Operating Hours Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Operating Hours Supply Fan= - 0-50000H 6
Ret/Exh Fan= - 0-50000H 6
Mech Cool= - 0-50000H 6
Comp # 1= - 0-50000H 6
Comp # 2= - 0-50000H 6
Comp # 3= - 0-50000H 6
Comp # 4= - 0-50000H 6
Comp # 5= - 0-50000H 6
Comp # 6= - 0-50000H 6
Comp # 7= - 0-50000H 6
Comp # 8= - 0-50000H 6
Heating= - 0-50000H 6
Economizer= - 0-50000H 6
Tnt Override= - 0-50000H 6
Dehum= - 0-50000H 6
ER Wheel= - 0-50000H 6
Supply Fan is a status item which gives the number of hours the supply fan has operated.
Return/Exhaust Fan is a status item which gives the number of hours the return/exhaust fans
have operated.
Mech Cool is a status item which gives the number of hours that mechanical cooling has
operated.
Comp #1 is a status item which gives the number of hours that compressor #1 has operated.
Comp #2 is a status item which gives the number of hours that compressor #2 has operated.
Comp #3 is a status item which gives the number of hours that compressor #3 has operated.
Comp #4 is a status item which gives the number of hours that compressor #4 has operated.
Comp #5 is a status item which gives the number of hours that compressor #5 has operated.
Comp #6 is a status item which gives the number of hours that compressor #6 has operated.
Comp #7 is a status item which gives the number of hours that compressor #7 has operated.
Comp #8 is a status item which gives the number of hours that compressor #8 has operated.
Heating is a status item which gives the number of hours that the heating mode has operated.
30 McQuay OM 920-1
Loading...