036-21528-007-A-1205
Unitary Products Group
27
B.
Shall have internal isolation and sound muffling to
minimize vibration and noise, and be externally iso-
lated on a dedicated, independent mounting.
2.
Coils:
A.
Evaporator and condenser coils shall have alumi-
num plate fins mechanically bonded to seamless
internally-enhanced copper tubes with all joints
brazed.
B.
Evaporator and Condenser coils shall be of the
direct expansion, draw-thru design.
3.
Refrigerant Circuit and Refrigerant Safety Compo-
nents shall include:
A.
Independent thermal expansion devices (TXV).
B.
Solid-core filter dryer to eliminate any foreign matter.
C.
Accessible service gage connections on both suc-
tion and discharge lines to charge, evacuate, and
measure refrigerant pressure during any necessary
servicing or troubleshooting, without losing charge
and without disrupting condenser or evaporator air
flow.
D.
The refrigeration system shall provide at least 10° F
of liquid sub-cooling at design conditions.
E.
Unit shall have a suction line accumulator and auto-
matic reversing valve.
4.
Unit Controls:
A.
Unit shall contain a large, low voltage Terminal
Board for easy connection of field low voltage wir-
ing.
B.
Controls shall be mounted in a large control box with
tilt-out, hinged access door, allowing easy access
for trouble shooting and maintenance without affect-
ing the normal system operation pressures.
C.
Unit shall contain a reliable demand defrost control
to provide defrost. The defrost control shall also
have an “X” terminal to provide a 24 volt signal for
room thermostat “LED” indication of unit lockout.
Plus a built in 5 minute anti-short cycle protection.
D.
Unit shall have large, easily removable panels, cov-
ering electrical controls and compressor, allowing
easy access for any maintenance or servicing.
ELECTRIC HEATING SECTION
1.
An electric heating section, with nickel chromium
elements, shall be provided in a range of 5 thru 25
KW.
2.
The heating section shall have an automatic reset
primary limit control to prevent the heating element
system from operating at an excessive tempera-
ture.
3.
The heating section assembly shall slide out of the
unit for easy maintenance and service.
4.
Units with electric heating sections shall be wired
for a single point power supply, with branch circuit
fusing (where required).
UNIT OPERATING CHARACTERISTICS
1.
Unit shall be capable of starting and running at
125° F outdoor temperature, exceeding maximum
load criteria of ARI Standard 210/240.
2.
The compressor, with standard controls, shall be
capable of operation down to 45° F outdoor tem-
perature.
ELECTRICAL REQUIREMENTS
All unit power wiring shall enter unit cabinet at a single
factory provided location and be capable of side or bot-
tom entry. This will minimize roof penetrations and
avoid unit field modifications. Separate side and bot-
tom openings shall be provided for the control wiring.
