Service manual

PRODUCT DESIGN
11
This section gives a basic description of cooling unit opera-
tion, its various components and their basic operation.
Ensure your system is properly sized for heat gain and loss
according to methods of the Air Conditioning Contractors
Association (ACCA) or equivalent.
CONDENSING UNIT
These units are designed for free air discharge. Condensed
air is pulled through the condenser coil by a direct drive
propeller fan and then discharged from the cabinet top. The
unit requires no additional resistance (i.e. duct work) and
should not be added.
The GSH13, GSH14 and ASH13 Heat Pump condensing
units are designed for 208-230 dual voltage single phase
applications. The GSH13 3 ton model is available in 230V, 3
phase applications. The GSH13 4 and 5 ton models are
available for 230V, 3-phase and 460V, 3-phase applications.
The units range in size from 1.5 to 5-ton and have a rating of
13 and 14 SEER. SEER efficiency is dependent upon the unit
and its components. Refer to the "Technical Information"
manual of the unit you are servicing for further details.
The GSC13, GSC14 and ASC13 Condensing Units are made
in 1.5 through 5 ton sizes. They are designed for 208-240 volt
single phase applications. The GSC13 3 ton model is avail-
able in 230V, 3 phase applications. The GSC13 4 and 5 ton
models are available for 230V, 3-phase and 460V, 3-phase
applications.
Suction and Liquid Line Connections
All units come equipped with suction and liquid valves
designed for connection to refrigerant-type copper. Front
seating valves are factory-installed to accept the field-run
copper. The total refrigerant charge needed for a normal
operation is also factory-installed. For additional refrigerant
line set information, refer to the "Technical Information"
manual of the unit you are servicing.
Compressors
GSC13 and GSH13 use a mix of reciprocating and scroll
compressors. The ASC13 and ASH13 use the Copeland
Scroll
®
Compressor. There are a number of design character-
istics which differentiate the scroll compressor from the
reciprocating compressor. One is the scroll. A scroll is an
involute spiral which, when matched with a mating scroll form,
generates a series of crescent-shaped gas pockets between
the members (see following illustration). During compres-
sion, one scroll remains stationary while the other form orbits.
This motion causes the resulting gas pocket to compress
and push toward the center of the scrolls. When the center
is reached, the gas is discharged out a port located at the
compressor center.
COILS AND BLOWER COILS
MBR/MBE blower cabinets are designed to be used as a two-
piece blower and coil combination. MBR/MBE blower sec-
tions can be attached to cased evaporator coil. This two-
piece arrangement allows for a variety of mix-matching
possibilities providing greater flexibility. The MBE blower
cabinet uses a variable speed motor that maintains a con-
stant airflow with a higher duct static.
It is approved for applications with cooling coils of up to 0.8
inches W.C. external static pressure and includes a feature
that allows airflow to be changed by +15%. The MBR blower
cabinet uses a PSC motor. It is approved for applications with
cooling coils of up to 0.5 inches W.C. external static
pressure.
The MBR/MBE blower cabinets with proper coil matches can
be positioned for upflow, counterflow, horizontal right or
horizontal left operation. All units are constructed with R-4.2
insulation. In areas of extreme humidity (greater than 80%
consistently), insulate the exterior of the blower with insula-
tion having a vapor barrier equivalent to ductwork insulation,
providing local codes permit.
The CAPX/CHPX coils are equipped with a thermostatic
expansion valve that has a built-in internal check valve for
refrigerant metering. The CACF/CAPF/CHPF coils are
equipped with a fixed restrictor orifice.
The coils are designed for upflow, counterflow or horizontal
application, using two-speed direct drive motors on the
CACF/CAPF/CHPX models and BPM (Brushless Perma-
nent Magnet) or ECM motors on the MBE models.
The ARUF is a multi-position air handler (upflow/horizontal
or downflow) and is equipped with a flowrator for cooling and
heat pump applications. Because of its seamless copper
tubing and aluminum fins, there are fewer leaks. The steel
cabinet of the ARUF is fully insulated and rust resistant.
Thermal expansion kits for air conditioning and heat pump
applications are available.
ARPF*B 2 to 5 ton air handlers are dedicated for downflow
operation and are approved for modular homes. Flowrater.
transformer and blower time delay are on all standard ARPF
units. Both the ARUF and ARPF have direct-drive multi-
speed motors.
The AEPT is a multi-position, variable-speed air handler that
features a factory-installed, internally mounted TXV. The
AEPT's blower motor allows for a soft start and stop for
quieter, more efficient operation and also eliminates the cold
blast of air upon heating startup.