GPG14M Service Manual

PRODUCT DESIGN
15
A 3/4" - 14 NPT drain connector is provided for removal of
condensate water from the indoor coil. In order to provide
proper condensate flow, do not reduce the drain line size.
NOTE: Tighten drain to a maximum torque of 10 in-lbs.
Refrigerant flow control is achieved by use of thermostatic
expansion valves (TXV) or flowrator.
The single phase models use permanent split capacitors
(PSC) design compressors. Starting components are there-
fore not required. A low MFD run capacitor assists the
compressor to start and remains in the circuit during opera-
tion.
A/GPG Package Gas Units are designed for outdoor instal-
lations only in either residential or light commercial applica-
tions and are available in 2, 2.5, 3, 3.5, 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
location within the return air duct. The minimum filter area
should not be less than those sizes listed in the Specification
Section. Under no circumstances should the unit be oper-
ated without return air filters.
A/GPG model units use EEM type indoor blower motors.
EEM motors are constant torque motors with very low power
consumption and are energized by a 24V signal from the
ignition control board. The EEM motors feature an inte-
grated control module.
Air for condensing (cooling cycle) is drawn through the
outdoor 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.
Most A/GPG series package units use the Compliant Scroll
compressor; there are a number of design characteristics
which are different from the traditional reciprocating com-
pressor.
- Due to their design Scroll compressors are inherently
more tolerant of liquid refrigerant. NOTE: Even though
the compressor section of a Scroll compressor is more
tolerant of liquid refrigerant, continued flood back or
flooded start conditions may wash oil from the bearing
surfaces causing premature bearing failure.
- These Scroll compressors use "POE" or polyolester oil
which is NOT compatible with mineral oilbased lubri-
cants 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
standard reciprocating compressors. This information
may be found in the “Cooling Performance Data” section.
A scroll is an involute spiral which, when matched with a
mating scroll form as shown, generates a series of crescent
shaped gas pockets between the two members.
During compression, one scroll remains stationary (fixed
scroll) while the other form (orbiting scroll) is allowed to orbit
(but not rotate) around the first form.
As this motion occurs, the pockets between the two forms
are slowly pushed to the center of the two scrolls while
simultaneously being reduced in volume. When the pocket
reaches the center of the scroll form, the gas, which is now
at a high pressure, is discharged out of a port located at the
center.
During compression, several pockets are being compressed
simultaneously, resulting in a very smooth process. Both the
suction process (outer portion of the scroll members) and the
discharge process (inner portion) are continuous.
ELECTRICAL WIRING
The units are designed for operation on 60 hertz current and
at voltages as shown on the rating plate. All internal wiring
is complete. Ensure the power supply to the compressor
contactor is brought to the unit as shown on the supplied unit
wiring diagram. The 24V wiring must be connected between
the unit control panel and the room thermostat.
LINE VOLTAGE WIRING
Power supply to the unit must be N.E.C. Class 1, and must
comply with all applicable codes. The unit must be electri-
cally grounded in accordance with the local codes or, in their
absence, with the latest edition of the National Electrical
Code, ANSI/NFPA No. 70, or in Canada, Canadian Electrical
Code, C22.1, Part 1. A fused disconnected must be provided
and sized in accordance with the unit minimum circuit
ampacity.
The best protection for the wiring is the smallest fuse or
breaker which will hold the equipment on line during normal
operation without nuisance trips. Such a device will provide
maximum circuit protection.