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3.Optional
a.Shall be constructed of copper fins mechanically bonded to copper tubes and copper tube sheets.
b.Galvanized steel tube sheets shall not be acceptable.
c.A polymer strip shall prevent coil assembly from contacting the sheet metal coil pan to minimize potential for galvanic corrosion between coil and pan.
4.Optional
a.Coating process shall ensure complete coil encapsulation of tubes, fins and headers.
b.Color shall be high gloss black with gloss per ASTM
c.Uniform dry film thickness from 0.8 to 1.2 mil on all surface areas including fin edges
d.Superior hardness characteristics of 2H per ASTM
e.Impact resistance shall be up to 160
f.Humidity and water immersion resistance shall be up to minimum 1000 and 250 hours respectively (ASTM
g.Corrosion durability shall be confirmed through testing to be no less than 1000 hours salt spray per ASTM
5.Optional
a.Shall have a flexible epoxy polymer coating uniformly applied to all coil surface areas without material bridging between fins.
b.Galvanized steel tube sheets shall not be acceptable.
c.A polymer strip shall prevent coil assembly from contacting sheet metal coil pan to maintain coating integ- rity and minimize corrosion potential between coil and pan.
d.Coating process shall ensure complete coil encapsulation of tubes, fins and headers.
e.Color shall be high gloss black with gloss per ASTM
f.Uniform dry film thickness from 0.8 to 1.2 mil on all surface areas including fin edges
g.Superior hardness characteristics of 2H per ASTM
h.Impact resistance shall be up to 160
i.Humidity and water immersion resistance shall be up to minimum 1000 and 250 hours respectively (ASTM
j.Corrosion durability shall be confirmed through testing to be no less than 1000 hours salt spray per ASTM
23 81 19.13.K. Refrigerant Components
1.Refrigerant circuit shall include the following control, safety, and maintenance features:
a.Fixed orifice metering system shall prevent
b.Refrigerant filter drier.
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 to route their pressure gauge lines.
c.This gauge access port shall facilitate correct and accurate condenser pressure readings by enabling the reading with the compressor access panel on.
d.The plug shall be made of a leak proof,
3.Compressors
a.Unit shall use one 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 using a Thermal Overload Disk (TOD) installed at the muffler plate on
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