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Two-Stage Indoor Split
Puron
®
Systems
49
Carrier Indoor & Outdoor Split Geothermal Heat Pumps - Rev.: 08/10/05
GT-PX Split (50YDS) Series
General
The liquid source heating/cooling split condensing
units shall be ARI/ISO/ASHRAE 13256-1 (ground-
source closed-loop) performance certi
fi
ed and listed
by a nationally recognized safety-testing laboratory or
agency, such as the Canadian Standards Association
(CSA US). Each unit shall be water run-tested at the
factory. Each unit shall be pallet mounted and shipped
with appropriate protective packaging to help avoid
damage in transportation. The units shall be warranted
by the manufacturer against defects in materials and
workmanship for a period of
fi
ve years on all parts, and
ten years on the compressor and refrigerant circuit
parts with a service labor allowance during the
fi
rst 30
days. An optional extended warranty is available for the
GT-PX Series units, which adds a labor allowance and
trip charge. The water source units shall be designed to
operate with entering
fl
uid temperature between 20°F
and 120°F.
Casing & Cabinet
The cabinet shall be fabricated from heavy-gauge
galvanized steel and painted with an epoxy powder
coating. The interior shall be insulated with 1/2” thick,
multi-density, coated glass
fi
ber. Three compressor
compartment access panels shall be provided and shall
be removable with linesets and water piping in place. The
internal component layout shall provide for major service
with the unit in-place for restricted access installations.
Refrigerant Circuit
All units shall contain Puron
®
(HFC 410A) sealed
refrigerant circuit employing a hermetic motor
compressor, bidirectional thermal expansion valve,
reversing valve, coaxial tube water-to-refrigerant heat
exchanger and service ports. An optional Hot Water
Generator (desuperheater) coil shall be provided.
Compressors shall be Copeland UltraTech™ Two-
Stage scroll type designed for heat pump duty and
mounted on spring vibration isolators. Compressor
motors shall be single phase PSC with internal over
load protection. A factory provided bidirectional
fi
lter
drier shall be included in all models. The coaxial water-
to-refrigerant heat exchangers shall be designed for
close approach temperatures and be construct ed of
a convoluted copper (optional cupronickel) inner tube
and a steel outer tube. The thermal expansion valve
shall provide proper superheat over the entire
fl
uid
temperature range with minimal “hunting”. The valve
shall operate only in the heating mode with the use of
an internal check valve. The water-to-refrigerant heat
exchanger, optional desuperheater coil and refrigerant
suction lines shall be insulated to prevent condensation
at low liquid temperatures.
Electrical
CXM Control - A microprocessor-based compressor
controller shall be provided to monitor and control
unit operation. The control shall provide compressor
sequencing, high and low pressure monitoring,
fi
eld
selectable low water temperature sensing, over/under
voltage monitoring, and unit performance sentinel
(UPS). The control shall also provide for water valve
connection, a test mode, short cycle protection, random
start-up, as well as fault LED, fault memory, and
intelligent fault retry.
The control shall employ quick attach harness
assemblies for low voltage connections to the control
board to aid in troubleshooting or replacement. An
integral terminal block with screw terminals shall be
provided on the control for
fi
eld low voltage connections.
A circuit breaker protected 75VA transformer shall be
employed. Line voltage box lugs shall be provided for
unit wiring. Units shall have knockouts for entrance of
low and line voltage wiring. The control box shall be
harness plug-connected for easy removal. Residential
models shall have a dual circut-breaker protected power
block for the connection of external Flow Controller
pump module.
Piping
Supply and return water connections, as well as Hot
Water Generator (desuperheater) connections shall be
1” FPT brass swivel
fi
ttings which provide a union and
eliminate the need for pipe wrenches and sealants when
making
fi
eld connections. A thread by sweat
fi
tting shall
be provided for connection to the water heater. All water
piping shall be insulated to prevent condensation at low
liquid temperatures.