Carrier MODU-PAC 50DF - Manual (Page 3)

50DF
High quality features assure easy installation
— plus performance and energy savings
Solid-state components for precise
system control — Units contain a
solid-state control system that pro­
vides maximum operating economy.
The “brain” of the system is a logic
panel that offers 2-stage heating and
cooling modes based on space re­
quirements. Panel also is the logic net­
work that coordinates operation of the
economizer, energy management and
two-speed indoor fan options.
Solid-state components require no
calibration, are easily replaced and
have long operating life.
Practical curb design for low in­
stallation costs — The curb supports
unit on the roof. Eliminates special steel
support frames and assures a low roof
silhouette.
Weatherproof enclosure
eliminates need for a rooftop adapter or
roof openings that could be sources
of troublesome leaks. All utilities enter
unit within the curb; saves time and
reduces installation costs. A wood nail-
strip is also included.
Adaptable duct connections — The
Carrier design provides large duct
openings that permit low airflow veloci­
ties and even air distribution. Bottom
supply and return ductwork is easily
installed. Concentric ductwork with
diffusers also may be connected to the
20-, 25-, and 30-ton units.. .with no
internal modifications.
For convenience, alternate side supply
and return openings are provided for
horizontal duct applications. Simply
relocate side supply and return panels,
place them in the bottom openings,
relocate one interior panel and the unit
is quickly converted for side duct con­
nection. An accessory conversion kit
is required for units with economizer.
Factory-installed filter rack includes
2-in. filters.
115-volt convenience outlet — An
on-the-job power source for service
light or hand tools.
Pre-installed tracks for hydronic coil
application. Factory installed on units
without electric heat option.
Weather Armor cabinet stands up to
the weather. Cabinet design exceeds
UL and Carrier rain test requirements.
Units keep attractive appearance for
years — even in salt air or heavy in­
dustrial environment.
Time Guard® circuit — Compressor
will not short cycle on a safety device or
power interruption. Starts outdoor air
fans 15 seconds before compressor to
minimize solar heat buildup and reduce
start-up load.
Single-location power connections
— Unit is factory wired with all heating
and cooling power circuits internally
routed to a terminal block in one com­
partment. Some units, with higher heat/
cool ratios, have 2 terminal blocks. No
need to route expensive wiring to
separate heating and cooling power
locations. Saves time, money and labor.
Fixed-speed evaporator fan drive —
less vibration than variable-speed drive.
Extends belt life and minimizes drive
noise.
Manual damper, on standard units,
can be preset to admit as much as 25%
outdoor air for year-round ventilation.
Cfficurr
8REA:
Built-in convenience — Quick-release
access panels, slide-out filters and plug­
in relays simplify routine inspection
and maintenance.
Carrier-built intertwined refrigerant
coils have staggered copper tubes with
mechanically bonded fins to ensure
optimum heat transfer. Intertwined
design provides cooling of the full air
stream with minimum compression.
Direct-drive condenser fans are
factory lubricated. Vertical discharge
moves air quietly and efficiently.
Carrier compressors have factory-
installed service valves, crankcase
heaters, reversible oil pumps, mufflers,
overloads in the control box and
internal motor protection. Liquid line
sight glasses and filter driers are also
included.
Low-ambient temperature capa­
bility permits all units to operate at out­
door temperatures as low as 35 F.
CON\gv(IENCE logic LOW VOLTAGE
OUTLET , PANEL TERNHNAL BLOCK
LOGIC PANEL CARRIER SERVICEABLE
HERMETIC COMPRESSORS
«LEAD
COMPRESSOR
(Uses Suction
Pressure)