3
GENERAL
This book contains Start-Up, Controls, Operation, Trouble-
shooting and Service information for the 48/50Z Series
rooftop units. See Table 1. These units are equipped with
ComfortLink™ controls version 4.X or higher. Use this guide
in conjunction with the separate installation instructions pack-
aged with the unit. Refer to the Wiring Diagrams literature for
more detailed wiring information.
The 48/50Z Series units provide ventilation, cooling, and
heating (when equipped) in variable air volume (VAV) and
constant volume (CV) applications.
Table 1 — Z Series Product Line
LEGEND
The 48/50Z units contain the factory-installed ComfortLink
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). Informa-
tion on system operation and status are sent to the MBB pro-
cessor by various sensors and optional board that are located at
the unit and in the conditioned space. Access to the unit con-
trols for configuration, set point selection, schedule creation,
and service can be done through a unit-mounted scrolling mar-
quee. Access can also be done through the Carrier Comfort
Network® using ComfortVIEW™ software, Network Service
Tool, or the accessory Navigator™ device.
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 can be equipped with optional IGV (inlet guide
vanes) or VFD (variable frequency drive) for supply duct pres-
sure control. The ComfortLink™ controls can directly control
the speed of the VFD based on a static pressure sensor input. In
addition the ComfortLink controls can adjust (but not control
on CV and non-modulating power exhaust units) the building
pressure using multiple power exhaust fans controlled from
damper position or from a building pressure sensor. The control
safeties are continuously monitored to prevent the unit from
operating under abnormal conditions. Sensors include suction
pressure transducers and saturated discharge pressure transduc-
ers which allow for display of the unit’s operational pressures.
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 lo-
cal display (scrolling marquee or Navigator™ accessory) will
be used in this manual.
Point names will be written with the Mode name first, then
any submodes, 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
→
IAQ
→
IAQ.SP
→
IQ.O.P.
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
UP ARROW and DOWN ARROW keys. The arrow symbol
in the path name represents pressing ENTER 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 parenthesis after the value. As an example, Configu-
ration
→
IAQ
→
AQ.CF
→
IQ.AC = 1 (IAQ Analog Input).
Pressing the ESCAPE and ENTER keys simultaneously
will scroll an expanded text description of the point name
across the display. The expanded description is shown in the
local display tables but will not be shown with the path names
in text.
The CCN point names are also referenced in the local
display tables for users configuring the unit with CCN software
UNIT SIZE APPLICATION
48ZG All Gas Heat, Vertical Supply
CV 2-Stage
48ZN All Gas Heat, Vertical Supply
VAV and CV Multi
50ZG All
Vertical Supply,
Optional Electric Heat
CV 2-Stage
50ZN All
Vertical Supply,
Optional Electric Heat
VAV and CV Multi
50Z2 All Horizontal Supply
CV 2-Stage
50Z3 All Horizontal Supply
VAV and CV Multi
48ZT 075-105
Gas Heat, Vertical Supply
High-Capacity Power Exhaust
CV 2-Stage
48ZW 075-105
Gas Heat, Vertical Supply
High-Capacity Power Exhaust
VAV and CV Multi
50ZT 075-105
Vertical Supply,
Optional Electric Heat
High-Capacity Power Exhaust
CV 2-Stage
50ZW 075-105
Vertical Supply,
Optional Electric Heat
High-Capacity Power Exhaust
VAV and CV Multi
50ZX 075-105
Horizontal Supply,
Optional Electric Heat
High-Capacity Power Exhaust
CV 2-Stage
50ZZ 075-105
Horizontal Supply,
Optional Electric Heat
High-Capacity Power Exhaust
VAV and CV Multi
48Z6 075-105
Gas Heat, Vertical Supply
Return/Exhaust Fan
CV 2-Stage
48Z8 075-105
Gas Heat, Vertical Supply
Return/Exhaust Fan
VAV and CV Multi
50Z6 075-105
Vertical Supply,
Optional Electric Heat
Return/Exhaust Fan
CV 2-Stage
50Z7 075-105
Horizontal Supply, Vertical Return Optional
Electric Heat
Return/Exhaust Fan
CV 2-Stage
50Z8 075-105
Vertical Supply,
Optional Electric Heat
Return/Exhaust Fan
VAV and CV Multi
50Z9 075-105
Horizontal Supply, Vertical Return
Optional Electric Heat
Return/Exhaust Fan
VAV and CV Multi
CV 2-Stage — Constant Volume, 2-Stage
CV Multi — Constant Volume, Multiple Adaptive Demand
VAV — Variable Air Volume