Installation and servicing of air-conditioning equipment can
be hazardous due to system pressure and electrical components. Only trained and qualified service personnel should install, repair, or service air-conditioning equipment. Untrained
personnel can perform the basic maintenance functions of replacing filters. Trained service personnel should perform all
other operations.
When working on air-conditioning equipment, observe precautions in the literature, tags and labels attached to the unit,
and other safety precautions that may apply. Follow all safety
codes. Wear safety glasses and work gloves. Use quenching
cloth for unbrazing operations. Have fire extinguishers available for all brazing operations.
WARNING
Before performing service or maintenance operation on
unit turn off and lock off main power switch to unit.
Electrical shock can cause personal injury and death.
Shut off all power to this equipment during installation
and service. The unit may have an internal non-fused
disconnect or a field-installed disconnect. Note that the
unit may also be equipped with a convenience outlet,
that this outlet is wired to the line side of the unitmounted disconnect and will remain hot when the
disconnect in the unit is off. There is a separate fuse/
disconnect for the convenience outlet.
CAUTION
Puron® refrigerant (R-410A) systems operate at higher
pressures than standard R-22 systems. Do not use R-22 service equipment or components on Puron refrigerant equipment. If service equipment is not rated for Puron
refrigerant, equipment damage or personal injury may
result.
CAUTION
This unit uses a microprocessor-based electronic control
system. Do not use jumpers or other tools to short out com-
ponents or to bypass or otherwise depart from recommended procedures. Any short-to-ground of the control
board or accompanying wiring may destroy the electronic
modules or electrical components.
WARNING
1. Improper installation, adjustment, alteration, service,
or maintenance can cause property damage, personal
injury, or loss of life. Refer to the User’s Information
Manual provided with this unit for more details.
2. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
What to do if you smell gas:
1. DO NOT try to light any appliance.
2. DO NOT touch any electrical switch, or use any phone
in your building.
3. IMMEDIATELY call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
4. If you cannot reach your gas supplier call the fire
department.
2
GENERAL
ENTER
ESCAPE
ENTER
This book contains Start-Up, Controls Operation, Troubleshooting and Service information for the 48/50A Series
rooftop units. See Table 1. These units are equipped with
ComfortLink™ controls.
Use this guide in conjunction with the separate installation
instructions packaged with the unit. Refer to the Wiring Diagrams literature for more detailed wiring information.
Table 1 — A Series Product Line
UNITAPPLICATION
48AJCV Unit with Gas Heat, Vertical Supply
48AKVAV Units with Gas Heat, Vertical Supply
48AWCV Unit with Gas Heat, Horizontal Supply
48AYVAV Unit with Gas Heat, Horizontal Supply
48A2CV Unit with Gas Heat, Vertical Supply with MCHX Coil
48A3VAV Unit with Gas Heat, Vertical Supply with MCHX Coil
48A4CV Unit with Gas Heat, Horizontal Supply with MCHX Coil
48A5VAV Unit with Gas Heat, Horizontal Supply with MCHX Coil
50AJCV Unit with Optional Electric Heat, Vertical Supply
50AKVAV Unit with Optional Electric Heat, Vertical Supply
50AWCV Unit with Optional Electric Heat, Horizontal Supply
50AYVAV Unit with Optional Electric Heat, Horizontal Supply
CV Unit with Optional Electric Heat, Vertical Supply with MCHX
50A2
Coil
VAV Unit with Optional Electric Heat, Vertical Supply with MCHX
50A3
Coil
CV Unit with Optional Electric Heat, Horizontal Supply with
50A4
MCHX Coil
VAV Unit with Optional Electric Heat, Horizontal Supply with
50A5
MCHX Coil
LEGEND
CV— Constant Volume
MCHX — Microchannel Heat Exchanger
VAV— Varia bl e Ai r Vol ume
The A Series units provide ventilation, cooling, and heating
(when equipped) in variable air volume (VAV), variable volume
and temperature (VVT®), and constant volume (CV) applications. The A Series units contain the factory-installed Com-fortLink™ control system which provides full system management. The main base board (MBB) stores hundreds of unit configuration settings and 8 time of day schedules. The MBB also
performs self diagnostic tests at unit start-up, monitors the operation of the unit, and provides alarms and alert information. The
system also contains other optional boards that are connected to
the MBB through the Local Equipment Network (LEN). Information on system operation and status are sent to the MBB processor by various sensors and optional boards that are located at
the unit. Access to the unit controls for configuration, set point
selection, schedule creation, and service can be done through a
unit-mounted scrolling marquee. Access can also be done
through the Carrier Comfort Network
ComfortVIEW™ software, the accessory Navigator™ handheld display, or the System Pilot™ interface.
The ComfortLink system controls all aspects of the rooftop.
It controls the supply-fan motor, compressors, and economizers to maintain the proper temperature conditions. The controls
also cycle condenser fans to maintain suitable head pressure.
All VAV units are equipped with a standard VFD (variable frequency drive) for supply fan speed control and supply duct
pressure control. The ComfortLink controls adjust the speed of
the VFD based on a static pressure sensor input. In addition,
the ComfortLink controls can raise or lower the building pressure using multiple power exhaust fans controlled from economizer damper position or from a building pressure sensor. The
control safeties are continuously monitored to ensure safe operation under all conditions. Sensors include suction pressure
transducers, discharge pressure transducers, and saturated condensing temperature sensors which allow for display of operational pressures and saturation temperatures.
®
(CCN) system using the
A scheduling function, programmed by the user, controls
the unit occupied/unoccupied schedule. Up to 8 different
schedules can be programmed.
The controls also allow the service person to operate a quick
test so that all the controlled components can be checked for
proper operation.
Conventions Used in This Manual — The follow-
ing conventions for discussing configuration points for the local display (scrolling marquee or Navigator accessory) will be
used in this manual.
Point names will be written with the Mode name first, then
any sub-modes, then the point name, each separated by an
arrow symbol (). Names will also be shown in bold and
italics. As an example, the IAQ Economizer Override Position
which is located in the Configuration mode, Indoor Air Quality
Configuration sub-mode, and the Air Quality Set Points
sub-sub-mode, would be written as Configuration
IAQIAQ.SPIQ.O.P. A list of point names can be found in
Appendix A.
This path name will show the user how to navigate through
the local display to reach the desired configuration. The user
would scroll through the modes and submodes using the
and keys. The arrow symbol in the path name represents pressing to move into the next level of the
menu structure.
When a value is included as part of the path name, it will be
shown at the end of the path name after an equals sign. If the
value represents a configuration setting, an explanation will be
shown in parentheses after the value. As an example, Configu-
ration
IAQAQ.CFIQ.AC= 1 (IAQ Analog Input).
Pressing the and keys simultaneously
at any time will display an expanded text description of the fourcharacter point name. The expanded description is shown in the
local display tables (Appendix A).
The CCN point names are also referenced in the local
display tables for users configuring the unit with CCN software
instead of the local display. The CCN tables are located in
Appendix B of this manual.
BASIC CONTROL USAGE
ComfortLink Controls —
system is a comprehensive unit-management system. The control system is easy to access, configure, diagnose and troubleshoot.
The control is flexible, providing two types of constant
volume cooling control sequences, two variable air volume
cooling control sequences, and heating control sequences for
two-stage electric and gas systems, and for multiple-stage gas
heating, in both Occupied and Unoccupied schedule modes.
This control also manages:
• VAV duct pressure (through optional VFD), with reset
• Building pressure through two different power exhaust
schemes
• Condenser fan cycling for mild ambient head pressure
control
• Space ventilation control, in Occupied and Unoccupied
periods, using CO
tilation defined by damper position
• Smoke control functions
• Occupancy schedules
• Occupancy or start/stop sequences based on third party
signals
• Alarm status and history and run time data
• Management of a complete unit service test sequence
sensors or external signals, with ven-
2
The ComfortLink control
3
System diagnostics are enhanced by the use of multiple
ESCAPE
ENTER
ESCAPE
ENTER
ENTER
ESCAPE
Run Status
Service Test
Temperature
Pressures
Setpoints
Inputs
Outputs
Configuration
Time Clock
Operating Modes
Alarms
Alarm Status
ENTER
MODE
ESCAPE
Fig. 1 — Scrolling Marquee
A30-2239
Ru
n Sta
tu
s
S
e
rv
ice
Te
s
t
T
em
p
era
ture
s
P
res
s
ure
s
S
e
tpo
in
ts
In
pu
ts
O
utp
uts
C
on
fig
u
ra
tion
T
im
e
Clo
ck
O
p
er
ating
M
od
es
A
la
rm
s
E
N
T
E
R
E
S
C
M
O
D
E
Ala
rm
Sta
tus
T
IM
E
E
W
T
L
W
T
S
E
T
P
1
2
.
5
8
5
4
.
6
F
4
4
.1
F
4
4
.
0
F
N
A
V
I
G
A
T
O
R
C
o
m
f
o
r
t
L
in
k
Fig. 2 — Accessory Navigator Display
30-650
external sensors for air temperatures, air pressures, refrigerant
temperatures, and refrigerant pressures. Unit-mounted actuators provide digital feedback data to the unit control.
The ComfortLink control system is fully communicating
and cable-ready for connection to the Carrier Comfort Net-
®
work
(CCN) building management system. The control provides high-speed communications for remote monitoring via
the Internet. Multiple units can be linked together (and to other
ComfortLink control equipped units) using a 3-wire communication bus.
The ComfortLink control system is easy to access through
the use of a unit-mounted display module. There is no need to
bring a separate computer to this unit for start-up. Access to
control menus is simplified by the ability to quickly select from
11 menus. A scrolling readout provides detailed explanations
of control information. Only four, large, easy-to-use buttons are
required to maneuver through the entire controls menu.
For added service flexibility, an accessory hand-held
Navigator module is also available. This portable device has an
extended communication cable that can be plugged into the
unit’s communication network either at the main control box or
at the opposite end of the unit, at a remote modular plug. The
Navigator display provides the same menu structure, control
access and display data as is available at the unit-mounted
scrolling marquee display.
Scrolling Marquee — This device is the standard inter-
face used to access the control information, read sensor values,
and test the unit. The scrolling marquee is located in the main
control box. The scrolling marquee display is a 4-key, 4-character LED (light-emitting diode) display module. The display
also contains an Alarm Status LED. See Fig. 1. The display is
easy to operate using 4 buttons and a group of 11 LEDs that indicate the following menu structures, referred to as modes (see
Appendix A):
• Run Status
• Service Test
• Temperatures
•Pressures
• Set points
• Inputs
• Outputs
• Configuration
• Timeclock
• Operating Modes
•Alarms
Through the scrolling marquee, the user can access all of the
inputs and outputs to check on their values and status, configure operating parameters plus evaluate the current decision status for operating modes. Because the A Series units are
equipped with suction pressure and saturated condensing
temperature transducers, the scrolling marquee can also display
refrigerant circuit pressures typically obtained from service
gages. The control also includes an alarm history which can be
accessed from the display. In addition, through the scrolling
marquee, the user can access a built-in test routine that can be
used at start-up commissioning to diagnose operational problems with the unit.
Accessory Navigator™ Display — The accessory
hand-held Navigator display can be used with the A Series
units. See Fig. 2. The Navigator display operates the same way
as the scrolling marquee device. The Navigator display is
plugged into the RJ-14 (LEN) jack in the main control box on
the COMM board. The Navigator display can also be plugged
into the RJ-14 jack located on the ECB (economizer control
board) located in the auxiliary control box.
Operation — All units are shipped from the factory with
the scrolling marquee display, which is located in the main control box. See Fig. 1. In addition, the ComfortLink™ controls
also support the use of the handheld Navigator display.
Both displays provide the user with an interface to the
ComfortLink control system. The displays have and
arrow keys, an key and an key. These
keys are used to navigate through the different modes of the
display structure. The Navigator and the scrolling marquee displays operate in the same manner, except that the Navigator
display has multiple lines of display and the scrolling marquee
has a single line. All further discussions and examples in this
document will be based on the scrolling marquee display. See
Table 2 for the menu structure.
The four keys are used to navigate through the display
structure, which is organized in a tiered mode structure. If the
buttons have not been used for a period, the display will default
to the AUTO VIEW display category as shown under the RUN
STATUS category. To show the top-level display, press the
key until a blank display is shown. Then
use the and arrow keys to scroll through the top-level
categories (modes). These are listed in Appendix A and will be
indicated on the scrolling marquee by the LED next to each
mode listed on the face of the display.
When a specific mode or sub-mode is located, push the
key to enter the mode. Depending on the mode, there
may be additional tiers. Continue to use the and keys
and the keys until the desired display item is found.
At any time, the user can move back a mode level by pressing
the key. Once an item has been selected the display
will flash showing the item, followed by the item value and
then followed by the item units (if any).
4
ENTER
ESCAPE
ENTER
ESCAPE
ENTER
ENTER
ENTER
ENTER
ESCAPE
ENTER
SCROLL
+
-
NAVIGATE/
EXIT
MODIFY/
SELECT
PAGE
Fig. 3 — System Pilot™ User Interface
A33-1050
Items in the Configuration and Service Test modes are
password protected. The display will flash PASS and WORD
when required. Use the and arrow keys to enter the
four digits of the password. The default password is 1111.
Pressing the and keys simultaneously
will scroll an expanded text description across the display indicating the full meaning of each display point. Pressing the
and keys when the display is blank
(MODE LED level) will return the display to its default menu
of rotating AUTO VIEW display items. In addition, the password will need to be entered again before changes can be made.
Changing item values or testing outputs is accomplished in
the same manner. Locate and display the desired item. If the
display is in rotating auto-view, press the key to stop
the display at the desired item. Press the key again so
that the item value flashes. Use the arrow keys to change the
value of state of an item and press the key to accept
it. Press the key and the item, value or units display
will resume. Repeat the process as required for other items.
If the user needs to force a variable, follow the same process
as when editing a configuration parameter. A forced variable
will be displayed with a blinking “f” following its value. For
example, if supply fan requested (FA N. F) is forced, the display
shows “YESf”, where the “f” is blinking to signify a force on
the point. Remove the force by selecting the point that is forced
with the key and then pressing the and arrow keys simultaneously.
Depending on the unit model, factory-installed options and
field-installed accessories, some of the items in the various
Mode categories may not apply.
System Pilot™ Interface — The System Pilot
(33PILOT-01) device is a component of Carrier’s 3V™ system
and serves as a user-interface and configuration tool for all Carrier communicating devices. The System Pilot device can be
used to install and commission a 3V zoning system, linkage
compatible air source, universal controller, and all other devices operating on the CCN system.
Additionally, the System Pilot device can serve as a
wall-mounted temperature sensor for space temperature
measurement. The occupant can use the System Pilot device to
change set points. A security feature is provided to limit access
of features for unauthorized users. See Fig. 3 for System Pilot
details.
CCN Tables and Display — In addition to the unit-
mounted scrolling marquee display, the user can also access the
same information through the CCN tables by using the Service
Tool or other CCN programs. Details on the CCN tables are
summarized in Appendix B. The variable names used for the
CCN tables and the scrolling marquee tables may be different
and more items are displayed in the CCN tables. As a reference, the CCN variable names are included in the scrolling
marquee tables and the scrolling marquee names are included
in the local display tables in Appendix B.
GENERICS STATUS DISPLAY TABLE — The GENERICS
points table allows the service/installer the ability to create a
custom table in which up to 20 points from the 5 CCN
categories (Points, Config, Service-Config, Set Point, and
Maintenance) may be collected and displayed.
In the Service-Config table section, there is a table named
“generics”. This table contains placeholders for up to 20 CCN
point names and allows the user to decide which points are displayed in the GENERICS points table under the local display.
Each one of these placeholders allows the input of an 8-character
ASCII string. Using a CCN interface, enter the Edit mode for the
Service-Config table “generics” and enter the CCN name for
each point to be displayed in the custom points table in the order
they will be displayed. When done entering point names, download the table to the rooftop unit control.
IMPORTANT: The computer system software
(ComfortVIEW™, Service Tool, etc.) that is used to
interact with CCN controls always saves a template of
items it considers as static (e.g., limits, units, forcibil-
ity, 24-character text strings, and point names) after
the software uploads the tables from a control. There-
after, the software is only concerned with run time
data like value and hardware/force status. With this in
mind, it is important that anytime a change is made to
the Service-Config table “generics” (which in turn
changes the points contained in the GENERICS point
table), that a complete new upload be performed. This
requires that any previous table database be
completely removed first. Failure to do this will not
allow the user to display the new points that have been
created and the CCN interface will have a different
table database than the unit control.
5
RUN
STATUS
Auto View of
Run Status
(VIEW)
Econ
Run Status
(ECON)
Cooling
Information
(COOL)
Mode
Trip Helper
(TRIP)
CCN
Linkage
(LINK)
Compressor
Run Hours
(HRS)
Compressor
Starts
(STRT)
Timeguards
(TMGD)
Software
Ver sio n
Numbers
(VERS)
SERVICE
TEST
Service Test Mode
(TEST)
Software
Command
Disable
(STOP)
Soft Stop
Request
(S.STP)
Supply Fan
Request
(FAN.F)
4 in. Filter
Change Mode
(F.4.CH)
Test Independent
Outputs
(INDP)
Te st F an s
(FANS)
Test Cooling
(COOL)
Test Heating
(HEAT)
Table 2 — Scrolling Marquee Menu Display Structure
Controls — Use the following steps for the controls:
IMPORTANT: Do not attempt to start unit, even
momentarily, until all items on the Start-Up Checklist
and the following steps have been completed.
Unit Preparation —
accordance with the installation instructions and applicable
codes.
Check that unit has been installed in
Unit Setup — Make sure that the economizer hoods have
been installed and that the outdoor filters are properly installed.
Internal Wiring — Ensure that all electrical connections
in the control box are tightened as required. If the unit has
staged gas heat make sure that the leaving air temperature
(LAT) sensors have been routed to the supply ducts as required.
Accessory Installation — Check to make sure that all
accessories including space thermostats and sensors have been
installed and wired as required by the instructions and unit
wiring diagrams.
Crankcase Heaters — Crankcase heaters are energized
as long as there is power to the unit, except when the compressors are running.
IMPORTANT: Unit power must be on for 24 hrs prior
to start-up of compressors. Otherwise damage to compressors may result.
Evaporator Fan — Fan belt and fixed pulleys are factory-
installed. See Tables 3-38 for fan performance. Remove tape
from fan pulley, and be sure that fans rotate in the proper direction. See Table 39 for motor limitations. See Tables 40A and
40B for air quantity limits. Static pressure drop for power
exhaust is negligible. To alter fan performance, see Evaporator
Fan Performance Adjustment section on page 130.
IMPORTANT: The unit is shipped with the unit control
disabled. To enable the control, set Local Machine Disable
(Service Test
1. Set any control configurations that are required (fieldinstalled accessories, etc.). The unit is factory configured
for all appropriate factory-installed options.
2. Enter unit set points. The unit is shipped with the set point
default values. If a different set point is required use the
scrolling marquee, Navigator™ accessory or Service
Tool software to change the configuration valves.
3. If the internal unit schedules are going to be used configure the Occupancy schedule.
4. Verify that the control time periods programmed meet
current requirements.
5. Using Service Test mode, verify operation of all major
components.
6. If the unit is a VAV unit make sure to configure the VFD
static pressure set point using the display. To checkout the
VFD use the VFD instructions shipped with the unit.
STOP) to No.
Gas Heat — Verify gas pressure before turning on gas heat
as follows:
1. Turn off field-supplied manual gas stop, located external
to the unit.
2. Connect pressure gages to supply gas tap, located at fieldsupplied manual shutoff valves.
3. Connect pressure gages to manifold pressure tap on unit
gas valve.
4. Supply gas pressure must not exceed 13.5 in. wg. Check
pressure at field-supplied shut-off valve.
5. Turn on manual gas stop and initiate a heating demand.
Jumper R to W1 in the control box to initiate heat.
6. Use the Service Test procedure to verify heat operation.
7. After the unit has run for several minutes, verify that
incoming pressure is 6.0 in. wg or greater and that the
manifold pressure is 3.5 in wg. If manifold pressure must
be adjusted refer to Gas Valve Adjustment section.
7
Table 3 — Fan Performance — 48AJ,AK020,025 and 48A2,A3020 Units
3. Variable air volume units will operate down to 70 cfm/ton. Performance at
70 cfm/ton is limited to unloaded operation and may be additionally limited
by edb and ewb conditions.
Bhp x 746
Motor efficiency
8
Table 5 — Fan Performance — 48AJ,AK,A2,A3035 Units
1. Fan performance is based on wet coils, economizer, roof curb, cabinet losses, and clean
2-in. filters.
0.20.40.60.81.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
1.21.41.61.82.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
2.22.42.62.83.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
3.23.43.63.84.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
2. Conversion — Bhp to watts:
Watts =
3. Var iable air volume units will operate down to 70 cfm/ton. Performance at 70 cfm/ton is
limited to unloaded operation and may be additionally limited by edb and ewb conditions.
Bhp x 746
Motor efficiency
9
Table 7 — Fan Performance — 48AJ,AK,A2,A3040 Units
1. Fan performance is based on wet coils, economizer, roof curb, cabinet losses, and clean 2-in.
filters.
0.20.40.60.81.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
1.21.41.61.82.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
101228.40104129.46106830.54109531.63112132.74
2.22.42.62.83.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
3.23.43.63.84.0
RpmBhpRpmBhpRpmBhpRpmBhpRpmBhp
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
2. Conversion — Bhp to watts:
Watts =
3. Variable air volume units will operate down to 70 cfm/ton. Performance at 70 cfm/ton is limited to
unloaded operation and may be additionally limited by edb and ewb conditions.
Bhp x 746
Motor efficiency
11
Table 11 — Fan Performance — 48AJ,AK,A2,A3060 Units
3. Variable air volume units will operate down to 70 cfm/ton. Performance at
70 cfm/ton is limited to unloaded operation and may be additionally limited
by edb and ewb conditions.
Bhp x 746
Motor efficiency
12
Table 13 — Fan Performance — 50AJ,AK027,030 and 50A2,A3025-030 Units
3. Variable air volume units will operate down to 70 cfm/ton. Performance at
70 cfm/ton is limited to unloaded operation and may be additionally limited
by edb and ewb conditions.
3. Variable air volume units will operate down to 70 cfm/ton. Performance at 70 cfm/ton is
limited to unloaded operation and may be additionally limited by edb and ewb conditions.
3. Variable air volume units will operate down to 70 cfm/ton. Performance at
70 cfm/ton is limited to unloaded operation and may be additionally limited
by edb and ewb conditions.
Bhp x 746
Motor efficiency
17
Table 23 — Fan Performance — 48AW,AY,A4,A5035 Units
3. Variable air volume units will operate down to 70 cfm/ton. Performance at
70 cfm/ton is limited to unloaded operation and may be additionally limited
by edb and ewb conditions.
Bhp x 746
Motor efficiency
21
Table 31 — Fan Performance — 50AW,AY027,030 and 50A4,A5025-030 Units
3. Variable air volume units will operate down to 70 cfm/ton. Performance at
70 cfm/ton is limited to unloaded operation and may be additionally limited
by edb and ewb conditions.
3. Variable air volume units will operate down to 70 cfm/ton. Performance at 70 cfm/ton is
limited to unloaded operation and may be additional limited by edb and ewb conditions.
3. Variable air volume units will operate down to 70 cfm/ton. Performance at 70 cfm/ton is limited to
unloaded operation and may be additionally limited by edb and ewb conditions.
1. Extensive motor and electrical testing on the Carrier units has ensured that
the full horsepower range of the motor can be utilized with confidence.
8.76.4923.5——7,71784.1
9.57.09—12.010.08,00888.5
10.27.6131.0——9,50289.5
11.88.80—15.012.09,83689.5
15.311.41 46.0——12,54391.0
18.013.43—22.019.014,75691.0
22.416.7160.0——18,36391.0
23.417.46—28.723.019,18391.0
28.921.5673.0——23,51191.7
29.421.93—37.428.423,91891.7
35.626.5691.0——28,74292.4
34.725.89—43.836.328,01592.4
8.76.49 23.5—7,07891.7
9.57.09—12.07,72891.7
10.27.61 30.0—8,29891.0
11.88.80—15.09,60091.7
15.311.4146.0—12,27391.7
18.013.43—22.014,43993.0
22.416.7159.0—17,85393.0
23.417.46—28.718,65093.6
28.921.56 73.0—23,03493.6
29.421.93—36.323,43293.6
35.626.5682.6—28,37493.6
34.725.89—41.727,65693.6
HIGH-EFFICIENCY MOTORS
PREMIUM-EFFICIENCY MOTORS
Using the fan motors up to the horsepower ratings shown in the Motor Limitations table will not result in nuisance tripping or premature motor failures. Unit warranty will not be affected.
2. All motors comply with Energy Policy Act (EPACT) Standards effective
October 24, 1997.
Maximum
Watts
Maximum
Watts
Maximum
Efficiency
Maximum
Efficiency
Table 40A — Air Quantity Limits (48AJ,AK,AW,AY,A2,A3,A4,A5)
NOTE: Variable air volume units will operate down to 70 cfm/ton in Cooling
mode. Performance at 70 cfm/ton is limited to unloaded operation and may be
also limited by edb (entering dry bulb) and ewb (entering wet bulb) conditions.
MINIMUM COOLING
AIRFLOW CFM
(CV)
MAXIMUM AIRFLOW
CFM
26
Table 40B — Air Quantity Limits (50AJ,AK,AW,AY,A2,A3,A4,A5)
*Operation at these levels may be limited by entering evaporator air wet bulb temperatures.
Min CFMMax CFM*Min CFMMax CFM
COOLINGELECTRIC HEAT
6,00015,000
10,50020,000
15,00027,000
CONTROLS QUICK START
The following section will provide a quick user guide to setting up and configuring the A Series units with ComfortLink™
controls. See Basic Control Usage section on page 3 for information on operating the control. For wiring information, refer
to unit wiring diagrams in the Major System Components section on page 101.
IMPORTANT: The ComfortLink controls provide the user
with numerous configuration options such as set points,
demand levels, reset, and many others. If the building
owner or design engineer has not provided specific recommendations for these configuration settings, it is suggested
that the installer do not make changes to the default factory
settings. The factory-configured default values are appropriate for many applications.
IMPORTANT: The unit is shipped with the unit control
disabled. Enable the control by setting Local Machine Disable (Service Test
STOP) to No.
Two-Stage Constant Volume Units with
Mechanical Thermostat — To configure the unit, per-
form the following:
1. The type of control is configured under Configuration
UNITC.TYP. Set C.TYP to 4 (TSTAT 2 STG).
2. Remove jumpers from R-W2 and W2-W1 on TB4 in the
control box.
3. See Economizer Options section on page 28 for additional economizer option configurations.
4. See Exhaust Options section on page 29 for additional
exhaust option configurations.
Two-Stage Constant Volume Units with Space
Sensor —
1. The type of control is configured under Configuration
2. Under Configuration
the space sensor by setting SPT.S to ENBL (enable).
3. Install jumpers between R-W2 and W2-W1 on TB4 in
the control box.
4. The space temperature set points are configured under the
Setpoints menu. The heating and cooling set points may
To configure the unit, perform the following:
UNITC.TYP. Set C.TYP to 6 (SPT 2 STG).
UNITSENSSPT.S, enable
be configured. See the Heating Control and Cooling
Control sections on pages 50 and 37 for further description on these configurations. The following set points
may be configured:
5. The degrees of demand from the space temperature set
points are configured under the Configuration
D.LV.T
submenu. See the Heating Control and Cooling Control
sections for further description on these configurations.
The following set points may be configured:
L.H.ONDemand Level Lo Heat On
H.H.ONDemand Level Hi Heat On
L.H.OFDemand Level Lo Heat Off
L.C.ONDemand Level Lo Cool On
H.C.ONDemand Level Hi Cool On
L.C.OFDemand Level Lo Cool Off
6. Under Configuration
UNITCV.FN, set CV.FN to 1
for continuous fan or 0 for automatic fan.
7. To program time schedules, set SCH.N=1 under Config-
uration
CCNSC.OVSCH.N to configure the
control to use local schedules.
8. Under the Timeclock
SCH.L submenu, enter the
desired schedule. See Time Clock Configuration section
on page 75 for further description of these configurations.
9. Under the Configuration
CCNSC.OV submenu, the
following schedules and overrides should be configured:
O.T.L.Override time limit
SPT.OSPT override enabled?
T58.OT58 override enabled?
10. See Economizer Options section on page 28 for additional economizer option configurations.
11. See Exhaust Options section on page 29 for additional
exhaust option configurations.
27
Variable Air Volume Units Using Return Air
Sensor or Space Temperature Sensor —
figure the unit, perform the following:
1. The type of control is configured under Configuration
UNITC.TYP. Set C.TYP to 1 (VAV-RAT) for return
air sensor. Set C.TYP to 2 (VAV-SPT) for space temperature sensor.
NOTE: For VAV with a space sensor (VAV-SPT), under
Configuration
space sensor by setting SPT.S to ENBL.
2. Install jumpers between R-W2 and W2-W1 on TB4 in
the control box.
3. The space temperature set points and the supply air set
points are configured under the Setpoints menu. The
heating and cooling set points must be configured. See
the Heating Control and Cooling Control sections for
further description on these configurations. Configure the
following set points:
OHSPOccupied Heat Setpoint
OCSPOccupied Cool Setpoint
UHSPUnoccupied Heat Setpoint
V. C . O NVAV Occupied Cool On Delta
V. C . O FVAV Occupied Cool Off Delta
SASPSupply Air Setpoint
4. To program time schedules, make sure SCH.N=1 under
Configuration
the control to use local schedules.
5. Under the Timeclock
sired schedule. See Time Clock Configuration section on
page 75 for further description of these configurations.
6. Under Configuration
ic Pressure Setpoint should be configured.
SP.SPStatic Pressure Setpoint
7. If supply air temperature reset is desired, under the
Configuration
points should be configured:
RS.CFEDT Reset Configuration
RTIOReset Ratio (if RS.CF = 1 or 2)
LIMTReset Limit (if RS.CF = 1 or 2)
RES.SEDT 4-20 mA Reset Input (if RS.CF = 3)
NOTE: Configure either RTIO and LIMT or RES.S. All three
are not used.
8. See the Economizer Options section on this page for additional economizer option configurations.
9. See the Exhaust Options section on page 29 for additional
exhaust option configurations.
UNITSENSSPT.S, enable the
CCNSC.OVSCH.N to configure
SCH.L submenu, enter the de-
SP
EDT.R submenu, the following set
SP.SP, the supply duct Stat-
To con-
Multi-Stage Constant Volume Units with
Mechanical Thermostat —
form the following:
1. Under Configuration
(TSTAT MULTI).
2. Remove jumpers from R-W2 and W2-W1 on TB4 in the
control box. Connect thermostat to TB4.
3. Under the Setpoints menu, set the following
configurations:
SA.HISupply Air Set Point Hi
SA.LOSupply Air Set Point Lo
4. See the Economizer Options section on this page for additional economizer option configurations.
To configure the unit, per-
UNITC.TYP, set C.TYP to 3
5. See the Exhaust Options section on page 29 for additional
exhaust option configurations.
Multi-Stage Constant Volume Units with
Space Sensor —
following:
1. Under Configuration
(SPT MULTI).
2. Install jumpers between R-W2 and W2-W1 on TB4 in
the control box.
3. Under the Setpoints menu, the following configurations
should be set:
OHSPOccupied Heat Setpoint
OCSPOccupied Cool Setpoint
UHSPUnoccupied Heat Setpoint
UCSPUnoccupied Cool Setpoint
GAPHeat-Cool Setpoint Gap
SA.HISupply Air Set Point Hi
SA.LOSupply Air Set Point Lo
4. The degrees of demand from the space temperature set
points are configured under the Configuration
submenu. See the Heating Control and Cooling Control
sections for further description on these configurations.
Configure the following set points:
L.H.ON Demand Level Lo Heat On
H.H.ON Demand Level Hi Heat On
L.H.OF Demand Level Lo Heat On
L.C.ONDemand Level Lo Cool On
H.C.ON Demand Level Hi Cool On
L.C.OFDemand Level Lo Cool On
5. Under Configuration
the space sensor by setting SPT.S to ENBL.
6. Under Configuration
for continuous fan or 0 for automatic fan.
7. To program time schedules, set SCH.N=1 under Config-
uration
trol to use local schedules.
8. Under the Timeclock
sired schedule. See Time Clock Configuration section on
page 75 for further description of these configurations.
9. See the Economizer Options section below for additional
economizer option configurations.
10. See the Exhaust Options section on page 29 for additional
exhaust option configurations.
CCNSC.OVSCH.N to configure the con-
Economizer Options — Under the Configuration
ECON submenu, the following set points may be configured:
EC.ENEconomizer Enabled?
EC.MNEconomizer Min.Position
EC.MXEconomizer Maximum Position
E.TRMEconomizer Trim for SumZ?
E.SELEcon Changeover Select
OA.E.COA Enthalpy Change Over Select
OA.ENOutdoor Enthalpy Compare Value
OAT.LHigh OAT Lockout Temp
O.DEWOA Dew Point Temp Limit
ORH.SOutside Air RH Sensor
Configuration
the minimum damper position.
To configure the unit, perform the
UNITC.TYP, set C.TYP to 5
D.LV.T
UNITSENSSPT.S, enable
UNITCV.FN, set CV.FN to 1
SCH.L submenu, enter the de-
ECONEC.MN should always be set for
28
Indoor Air Quality (IAQ) Options
DEMAND CONTROLLED VENTILATION — Under
Configuration
parameters should be set to establish the minimum and maximum points for outdoor air damper position during demand
controlled ventilation (DCV):
absolute minimum vent position (or maximum reset) under
DCV.
Configuration
minimum damper position (or with no DCV reset). This is also
referenced in the economizer section.
IAQDCV.C, the following configuration
IAQDCV.CIAQ.M is used to set the
IAQDCV.CEC.MN is used to set the
Exhaust Options — The A Series units can be config-
ured with constant volume 2-stage power exhaust or modulating power exhaust. The following exhaust options should be
configured.
Configuration
Option) — For two-stage exhaust, under the Configuration
BP submenu, configure the following:
BP.P1Power Exhaust On Setp.1
BP.P2Power Exhaust On Setp.2
Configuration
Option) — For modulating exhaust, in the Configuration
BP submenu, configure the following:
BP.SPBuilding Pressure Setp.
BP
BP
BF.CF=1 (Two-Stage Exhaust
BF.CF=2 (Modulating Power Exhaust
Programming Operating Schedules — The
ComfortLink™ controls will accommodate up to eight different schedules (Periods 1 through 8), and each schedule is
assigned to the desired days of the week. Each schedule
includes an occupied on and off time. As an example, to set an
occupied schedule for 8 AM to 5 PM for Monday through
Friday, the user would set days Monday through Friday to ON
for Period 1. Then the user would configure the Period 1
Occupied From point to 08:00 and the Period 1 Occupied To
point to 17:00. To create a different weekend schedule, the user
would use Period 2 and set days Saturday and Sunday to ON
with the desired Occupied On and Off times. To create a schedule, perform the following procedure:
NOTE: By default, the time schedule periods are programmed
for 24 hours of occupied operation.
1. Scroll to the Configuration mode, and select CCN
CONFIGURATION (CCN). Scroll down to the Schedule
Number (Configuration
password protection has been enabled, the user will be
prompted to enter the password before any new data is
accepted. SCH.N has a range of 0 to 99. The default value is 1. A value of 0 is always occupied, and the unit will
control to its occupied set points. A value of 1 means the
unit will follow a local schedule, and a value of 65 to 99
means it will follow a CCN schedule. Schedules 2 to 64
are not used as the control only supports one internal/local schedule. If one of the 2 to 64 schedules is configured,
then the control will force the number back to 1. Make
sure the value is set to 1 to use a local schedule.
2. Enter the Time Clock mode. Scroll down to the LOCAL
TIME SCHEDULE (SCH.L) sub-mode, and press
ENTER. Period 1 (PER.1) will be displayed. Press ENTER to configure Period 1.
3. Configure the beginning of the occupied time period for
Period 1 (OCC). Scroll down to OCC and press ENTER
to go into Edit mode. The first two digits of the 00.00 will
start flashing. Use the UP or DOWN key to display the
CCNSC.OVSCH.N). If
correct value for hours, in 24-hour (military) time. Press
ENTER and hour value is saved and the minutes digits
will start flashing. Use the same procedure to display and
save the desired minutes value. Press ESCAPE.
4. Configure the unoccupied time for period 1 (UNC).
Scroll down to UNC and press ENTER to go into Edit
mode. The first two digits of the 00.00 will start flashing.
Use the UP or DOWN key to display the correct value for
hours, in 24-hour (military) time. Press ENTER and hour
value is saved and the minutes digits will start flashing.
Use the same procedure to display and save the desired
minutes value. Press ESCAPE.
5. Scroll to DAYS and press ENTER. Scroll down to the
MON point. This point indicates if schedule 1 applies to
Monday. Use the ENTER command to go into Edit
mode, and use the UP or DOWN key to change the display to YES or NO. Scroll down through the rest of the
days and apply schedule 1 where desired. The schedule
can also be applied to a holiday. Press ESCAPE.
6. The first schedule is now complete. If a second schedule
is needed, such as for weekends or holidays, scroll down
and repeat the entire procedure for period 2 (PER.2). If
additional schedules are needed, repeat the process for as
many as are needed. Eight schedules are provided.
SERVICE TEST
General —
ture, which is intended to allow a service person to force the
unit into different modes of operation to test them. To use this
feature, enter the Service Test category on the local display and
place the unit into the test mode by changing Service
Te st
TEST from OFF to ON. The display will prompt for the
password before allowing any change. The default password is
1111. Once the unit enters the Service Test mode, the unit will
shut down all current modes.
TEST — The TEST command turns the unit off (hard stop)
and allows the unit to be put in a manual control mode.
STOP — The STOP command completely disables the unit
(all outputs turn off immediately). Once in this mode, nothing
can override the unit to turn it on. The controller will ignore all
inputs and commands.
S.STP — Setting Soft Stop to YES turns the unit off in an
orderly way, honoring any time guards currently in effect.
FAN. F — By turning the FAN FORCE on, the supply fan is
turned on and will operate as it normally would, controlling
duct static pressure on VAV applications or just energizing the
fan on CV applications. To remove the force, press ENTER
and then press the UP and DOWN arrows simultaneously.
F. 4 . C H — The 4-Inch Filter Change Mode variable is used to
service the unit when 4-in. filters are used. When the filters
need to be changed, set Service Test
will be placed in Service Test mode and the economizer will
move to the 40% open position to facilitate removal of the 4-in.
filters. After the filters have been changed, set Service
Te st
F. 4 . C H = NO to return the unit to normal operation.
The remaining categories: INDP, FANS, COOL, andHEAT are sub-modes with separate items and functions. See
Table 41.
The units are equipped with a Service Test fea-
F. 4 . C H = YES. The unit
Service Test Mode Logic — Operation in the Service
Test mode is sub-mode specific except for the Independent submode. Leaving the sub-mode while a test is being performed
and attempting to start a different test in the new sub-mode will
cause the previous test to terminate. When this happens, the
new request will be delayed for 5 seconds. For example, if compressors were turned on under the COOL sub-mode, any attempt to turn on heating stages within the HEAT sub-mode
would immediately turn off the compressors and, 5 seconds later, the controller would honor the requested heat stages.
29
However, it is important to note that the user can leave a
Service Test mode to view any of the local display modes and
the control will remain in the Service Test mode.
Independent Outputs — The INDP sub-mode items
can be turned on and off regardless of the other category states.
For example, the alarm relay can be forced on in the INDP
sub-mode and will remain on if compressor relays are requested in the COOL sub-mode.
Fans in Service Test Mode — Upon entering the
FA NS sub-mode, the user will be able to turn the supply fan on
and off, set the supply fan VFD speed, and turn the condenser
fans on and off.
Cooling in Service Test Mode — The COOL sub-
mode offers different cooling service tests.
The user has manual relay control of individual compressors. If the user energizes mechanical cooling, the supply fan
and the outdoor fans will be started automatically. During
mechanical cooling, the unit will protect itself. Compressor
diagnostics are active, monitoring for high discharge pressure,
low suction pressure, etc. The user can also turn the hot gas
bypass valve on and off.
NOTE: It is crucial that proper compressor rotation be verified
during the service test. Each compressor must be tested
individually. After starting each compressor, the control will
check the suction pressure after 5 seconds of run time. If the
control does not see a sufficient decrease in suction pressure
after 5 seconds, mechanical cooling will be shut down, and an
alarm will be generated (A140). This alarm requires a manual
reset. If this alarm occurs, do not attempt a restart of the
compressor and do not attempt to start any other compressors
until the wiring to the unit has been corrected.
Heating in Service Test Mode — If unit has a ther-
mostat connected (C.TYP = 3 or 4), install the RED jumper
wires between TB4, terminals R (1), W2 (3) and W1 (4). Terminal block TB4 is located in the unit control box. Remember
to disconnect these jumpers when Test Mode is completed. The
Heat Test Mode sub-mode will offer automatic fan start-up if
the unit is not a gas heat unit. On gas heat units, the IGC feedback from the gas control units will bring the fan on as
required.
Within this sub-mode, the user has control of heat relays 1
to 6. The user can also turn on the requested heat stage.
NOTE: When service test has been completed, if unit has a
thermostat connected (C.TYP = 3 or 4), remove the RED
jumper wires at TB4, terminals R (1), W2 (3) and W1 (4).
Terminal block TB4 is located in the unit control box. Store
these jumpers in the unit control box for future use.
Table 41 — Service Test
ITEMEXPANSIONRANGEUNITSPOINTWRITE STATUS
TESTService Test ModeON/OFFMAN_CTRL
STOPLocal Machine DisableYES/NOUNITSTOPconfig
S.STPSoft Stop RequestYES/NOSOFTSTOPforcible
FAN.FSupply Fan RequestYES/NOSFANFORCforcible
F.4 . CH4 in. Filter Change ModeYES/NOFILT4CHG
INDPTEST INDEPENDENT OUTPUTS
ECONEconomizer Act.Cmd.Pos.ECONCTST
E.PWREconomizer Power TestECONPTST
E.CALCalibrate the Economizer?ECON_CAL
S.FANSupply Fan RelayON/OFFSFAN_TST
S.VFDSupply Fan VFD Speed0-100%SGVFDTST
CD.F.ACondenser Fan Circuit AON/OFFCNDA_TST
CD.F.BCondenser Fan Circuit BON/OFFCNDB_TST