PRODUCT DESIGN
4
*PG15 Package Gas Units are designed for outdoor installa-
tions only in either residential or light commercial applica-
tions and are available in 2, 2-1/2, 3, 3-1/2, 4 & 5 ton sizes.
They are designed for 208/230 volt single phase applications.
The connecting ductwork (Supply and Return) can be con-
nected for either horizontal or vertical airflow. In the vertical
application, a matching Roof Curb is recommended.
A return air filter must be installed behind the return air grille(s)
or provision must be made for a filter in an accessible loca-
tion within the return air duct. The minimum filter area should
not be less than those sizes listed in the Specification Sec-
tion. Under no circumstances should the unit be operated
without return air filters.
A 3/4" pipe is provided for removal of condensate water from
the indoor coil. (Do not reduce the drain line size).
Refrigerant flow control is achieved by use of a TXV or ori-
fice.
*PG15 units use the FasTest Access Fitting System which
consists of a saddle that is either soldered to the suction and
liquid lines or is fastened with a locking nut to the access
fitting box (core) and then screwed into the saddle.
NOTE:
The core must not be removed from the saddle until
the refrigerant charge has been removed. Failure to do
so could result in property damage or personal injury.
The single phase units use permanent split capacitors (PSC)
design compressors. Starting components are therefore not
required. A low MFD run capacitor assists the compressor
to start and remains in the circuit during operation.
The *PG15*****41AA models are equipped with X-13 blower
motors. X-13 motors are constant torque motors with very
low power consumption and are energized by a 24V signal
from the ignition control board. The X-13 features an inte-
grated control module.
Air for condensing (cooling cycle) is drawn through the out-
door coil by a propeller fan, and is discharged vertically out
the top of the unit. The outdoor coil is designed for .0 static.
No additional restriction (ductwork) shall be applied.
Conditioned air is drawn through the filter(s), field installed,
across the coil and back into the conditioned space by the
indoor blower.
The *PG15 series package units use the Compliant Scroll
compressor; there are a number of design characteristics
which are different from the traditional reciprocating compres-
sor.
- Due to their design Scroll compressors are inherently more
tolerant of liquid refrigerant.
NOTE
: Even though the com-
pressor section of a Scroll compressor is more tolerant of
liquid refrigerant, continued flood back or flooded start condi-
tions may wash oil from the bearing surfaces causing prema-
ture bearing failure.
- These Scroll compressors use "POE" orpolyolester oil which
is NOT compatible with mineral oilbased lubricants like 3GS.
"POE" oil must be used if additional oil is required.
- Compliant scroll compressors perform “quiet” shutdowns
that allow the compressor to restart immediately without the
need for a time delay. This compressor will restart even if the
system has not equalized.
- Operating pressures and amp draws may differ from stan-
dard reciprocating compressors. This information may be
found in the “Cooling Performance Data” section.
Some other models of the *PG15 series package units use a
2 stage scroll compressor. The basic scroll design has been
modified with the addition of an internal unloading mecha-
nism that opens a by-pass port in the first compression
pocket, effectively reducing the displacement of the scroll.
The opening and closing of the by-pass port is controlled by
an internal electrically operated solenoid.
The ZPS modulated scroll uses a single step of unloading
to go from full capacity to approximately 67% capacity. A
single speed, high efficiency motor continues to run while
the scroll modulates between the two capacity steps.
