TranSystems Corporation - LGM Construction

501070099 Federal Express Oakland Sort Expansion Issued for Bid 10/11
D. Provide vertical discharge, direct drive fans with steel blades, and three phase motors.
Fans shall be statically and dynamically balanced. Motors shall be permanently lubricated,
with built-in current and thermal overload protection and weathertight slinger over motor
bearings.
E. Provide factory-installed louvered steel coil guards around perimeter of condensing
section to protect the condenser coils, refrigerant piping and control components.
Louvered panels shall be fabricated from heavy gauge galvanized steel and be rigid
enough to provide permanent protection for shipping and pre-/post- installation. Course
wire mesh is not an acceptable material for coil guards.
F. Condenser coils shall be V-banked for cleaning ease. The coils shall not exceed 14 fins
per inch density in order to permit routine cleaning, and prevent excessive air pressure
drop across the condenser coil.
2.9 REFRIGERATION SYSTEM
A. Compressor: shall be industrial grade, energy efficient direct drive 3600 RPM maximum
speed reciprocating or scroll type. The motor shall of a suction gas cooled hermetic
design. Compressor shall have centrifugal oil pump with dirt separator, oil sight glass, and
oil charging valve.
B. If semi-hermetic reciprocating industrial grade compressors are utilized provide single
piece crankshafts, connecting rods aluminum pistons, rings to prevent gas leakage, high
strength non-flexing ring type suction and discharge valves, spring loaded heads,
replaceable cylinder liners, and sealing service immersed in oil. Provide removable
discharge heads and hand hole covers, and discharge service valves.
C. Provide with thermostatic motor winding temperature control to protect against excessive
motor temperatures resulting from over-/under-voltage or loss of charge. Provide high and
low pressure cutouts, and reset relay.
D. Provide factory-installed compressor lockout thermostat to prevent compressor operation
at low ambient conditions.
E. Provide coil frost protection compressor unloading based on refrigerant circuit suction
temperature to prevent coil frosting with minimum energy usage. As an alternate, factoryinstalled
hot gas bypass shall be required on all VAV units to prevent coil frosting.
2.10 EXHAUST/RETURN SECTION
A. 100 Percent Modulating Return Fan single width plenum fan with airfoil blade shall be
mounted on a shaft with fixed sheave drive. The fan shall be dynamically balanced for the
operating envelop and tested in factory before being installed in unit. The plenum fan shall
be test run in unit as part of unit test. Fan operating envelope rpm shall be below first
critical speed. Fan shaft shall be mounted on two grease lubricated ball or roller bearings
designed for 200,000-hour average life. Extended grease lines shall be provided to allow
PACKAGED ROOFTOP AIR CONDITIONING UNITS 15733-7