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g. Humidity and water immersion resistance shall be up to minimum 1000 and 250 hours respectively (ASTM
D2247--92 and ASTM D870--92).
h. Corrosion durability shall be confirmed through testing t o be no less than 1000 hours salt spray per ASTM
B117--90.
5. Standard All Aluminum Novation Coils:
a. Standard condenser coils shall have all aluminum NOVATION Heat Exchanger Technology design consisting
of aluminum multi port flat tube design and aluminum fin. Coils shall be a furnace brazed design and contain
epoxy lined shrink wrap on all aluminum to copper connections.
b. Condenser coils shall be leak tested to 150 psig, pre ssure tested to 650 psig, and qualified to UL 1995 burst
test at 1980 psig.
6. Optional E--coated aluminum--fin, aluminum tube condenser coils:
a. Shall have a flexible epoxy polymer coa ting uniformly applied to all coil external surface areas without mater-
ial bridging between fins or louvers.
b. Coating process shall ensure complete coil encapsulat ion, including all exposed fi n edges.
c. E--coat thickness of 0.8 to 1.2 mil with t op coat having a uniform dry film thickness from 1.0 to 2.0 mil on all
external coil surface areas, including fin edges, shall be provided.
d. Shall have superior hardness characteristics of 2H per ASTM D3363--00 and cross--hat ch adhe sion of 4B--5B
per ASTM D3359--02.
e. Shall have superior impact resistance with no cracking, chipping or peeli ng per NSF/ANSI 51--2002 Method
10.2.
23 81 19.13.K. Refri gerant Components
1. Refrigerant circuit shall include the following control, safety, and maintena nce fe atures:
a. Fixed orifice metering system shall prevent mal --distribution of two--phase refrigerant by including multiple
fixed orifice devices in each refrigeration circuit. Each orifice is to be optimized to the coil circuit it serves.
b. Refrigerant filter drier -- Solid core design.
c. Service gauge connections on suction and discharge lines.
d. Pressure gauge access through a specially designed access port in the top panel of the unit.
2. There shall be gauge line access port in the skin of the rooftop, covered by a black, removable plug.
a. The plug shall be easy to remove and replace.
b. When the plug is removed, the gauge access port shall enable maintenance personnel t o route their pressure
gauge lines.
c. This gauge access port shall facilitate correct and accurate condenser pressure readings by enabling the read-
ing with the compressor access panel on.
d. The plug shall be made of a leak proof, UV--resistant, composite material.
3. Compressors
a. Unit shall use fully hermetic, scroll compressor for each independent refrigeration circuit.
b. Compressor motors shall be cooled by refrigerant gas passing through motor windings.
c. Compressors shall be internally protected from high discharge temperature conditions.
d. Compressors shall be protected from an over--temperature and over--amperage conditions by an internal, motor
overload device.
e. Compressor shall be factory mounted on rubber grommets.
f. Compressor motors shall have internal line break thermal, current overload and high pressure differential pro-
tection.
g. Crankcase heaters shall not be required for normal operating range, unless required by compressor manufac-
turer due to refrigerant charge limits.
23 81 19.13.L. Filter Section
1. Filters access is specified in the unit cabinet section of this specification.
2. Filters shall be held in place by a pivoting filter tray, facilitating easy removal and installation.
3. Shall consist of factory installed, low velocity, throw-- away 2--in. thick fiberglass filters.
4. Filters shall be standard, commercially available sizes.
5. Only one size filter per unit is allowed.
23 81 19.13.M. Evaporat or Fan and Motor
1. Evaporator fan motor:
a. Shall have permanently lubricated bearings.
b. Shall have inherent automatic--reset thermal overload protection or circuit breaker.
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