refrigerant flow to the expansion device over the specified application
range of the condenser. Unit shall be provide with [manufacturer's
standard] [not less than [4] [_____] degrees C [8] [_____] degrees F]
liquid subcooling. Subcooling circuit shall be liquid sealed.
2.7.1.3
Condensing Coil
**************************************************************************
NOTE: Delete the copper or aluminum tubes and the
0.076 mm (3 mil) coating except in corrosive
environments.
**************************************************************************
Coils shall have [nonferrous] [copper or aluminum] tubes of 10 mm 3/8 inch
minimum diameter with copper or aluminum fins that are mechanically bonded
or soldered to the tubes. Coils shall be protected with a minimum 0.076 mm
3 mil thick [phenolic] [or] [vinyl] coating. Casing shall be galvanized
steel or aluminum. Contact of dissimilar metals shall be avoided. Coils
shall be tested in accordance with ASHRAE 15 at the factory and be suitable
for the working pressure of the installed system. Each coil shall be
dehydrated and sealed after testing and prior to evaluation and charging.
Each unit shall be provided with a factory operating charge of refrigerant
and oil or a holding charge. Unit shipped with a holding charge shall be
field charged. Separate expansion devices shall be provided for each
compressor circuit.
2.7.1.4
Unit Controls
The control system shall be complete with required accessories for
regulating condenser pressure by fan cycling, solid-state variable fan
speed, modulating condenser coil or fan dampers, flooding the condenser, or
a combination of the above. Unit mounted control panels or enclosures
shall be constructed in accordance with applicable requirements of NFPA 70
and housed in NEMA ICS 6, Class 1 or 3A enclosures. Controls shall include
[control transformer,] [fan motor [starters,]] [solid-state speed control,]
[electric heat tracing controls,] [time delay start-up,] overload
protective devices, interface with local and remote components, and
intercomponent wiring to terminal block points.
2.7.2
Evaporative Condenser
Each unit shall be the counter-flow blow-through design, with single-side
air entry. The unit shall have fan assemblies built into the unit base,
with all moving parts factory mounted and aligned. Primary construction of
the pan section, the cabinet, etc. shall be not lighter than 1.6 mm 16-gauge
steel, protected against corrosion by a zinc coating. The zinc coating
shall conform to ASTM A 153/A 153M and ASTM A 123/A 123M, as applicable and
have an extra heavy coating of not less than 0.76 kg/square meter 2.5
ounces/square foot of surface. Cut edges shall be given a protective
coating of zinc-rich compound. After assembly, the manufacturer's standard
zinc chromatized aluminum or epoxy paint finish shall be applied to the
exterior of the unit. Unit shall be rated in accordance with ARI 490 and
tested in accordance with the requirements of ASHRAE 64.
2.7.2.1
Pan Section
The pan shall be watertight and be provided with drain, overflow, and
make-up water connections. Standard pan accessories shall include circular
access doors, a lift-out strainer of anti-vortexing design and a brass
SECTION 15700A
Page 25
Previous Page
