Bryant 549C manual GUIDE SPECIFICATIONS — 542J150,180 cont

GUIDE SPECIFICATIONS — 542J150,180 (cont)

E.Coils:

1.Standard indoor and outdoor coils shall have copper or aluminum plate fins mechanically bonded to seamless internally grooved copper tubes with all joints brazed.

2.Coils shall be leak tested at 150 psig (1034 kPa) and pressure tested at 450 psig (3103 kPa).

3.Coils:

a.Copper-fin coils shall be constructed of copper fins mechanically bonded to copper tubes and copper tube sheets. Galvanized steel tube sheets shall not be acceptable. A polymer strip shall pre- vent coil assembly from contacting the sheet metal coil pan to minimize potential for galvanic corrosion between coil and pan. All copper con- struction shall provide protection in moderate coastal environments.

b.E-Coated aluminum-fin coils shall have a flexible epoxy polymer coating uniformly applied to all coil surface areas without material bridging between fins. Coating process shall ensure complete coil encapsulation. Color shall be high gloss black with gloss — 60 deg of 65 to 90% per ASTM D523-89. Uniform dry film thickness from 0.8 to

1.2mil on all surface areas including fin edges. Superior hardness characteristics of 2H per ASTM D3363-92A and cross-hatch adhesion of 4B-5B per ASTM D3359-93. Impact resistance shall be up to 160 in.-lb (ASTM D2794-93). Humidity and water immersion resistance shall be up to minimum 1000 and 250 hours respectively (ASTM D2247-92 and ASTM D870-92). Corro- sion durability shall be confirmed through testing to be no less than 1000 hours salt spray per ASTM B117-90. Coil construction shall be alumi- num fins mechanically bonded to copper tubes.

c.E-Coated copper-fin coils shall have a flexible epoxy polymer coating uniformly applied to all coil surface areas without material bridging between fins. Coating process shall ensure complete coil encapsulation. Color shall be high gloss black with gloss — 60 deg of 65 to 90% per ASTM D523-89. Uniform dry film thickness from 0.8 to

1.2mil on all surface areas including fin edges. Superior hardness characteristics of 2H per ASTM D3363-92A and cross-hatch adhesion of 4B-5B per ASTM D3359-93. Impact resistance shall be up to 160 in.-lb (ASTM D2794-93). Humidity and water immersion resistance shall be up to minimum 1000 and 250 hours respectively (ASTM D2247-92 and ASTM D870-92). Corro- sion durability shall be confirmed through testing to be no less than 1000 hours salt spray per ASTM B117-90. Coil construction shall be copper fins mechanically bonded to copper tubes with copper tube sheets. Galvanized steel tube sheets shall not be acceptable. A polymer strip shall pre- vent coil assembly from contacting sheet metal coil pan to maintain coating integrity and minimize corrosion potential between coil and pan.

d.Optional pre-coated aluminum-fin coils shall have a durable epoxy-phenolic coating to provide pro- tection in mildly corrosive coastal environments. Coating shall be applied to the aluminum fin stock prior to the fin stamping process to create an inert barrier between the aluminum fin and copper

tube. Epoxy-phenolic barrier shall minimize gal- vanic action between dissimilar metals.

F.Heating Section:

1.May be equipped with field-installed electric resis- tance heater(s) of the characteristics shown in the equipment schedule.

2.Heater elements shall be open wire, adequately supported and insulated with ceramic bushings.

G.Refrigerant Components:

Refrigerant circuit components shall include:

1.Fixed orifice metering system (AcutrolTM device).

2.Refrigerant filter drier.

3.Reversing valve.

4.Service gage connections on suction, discharge, and liquid lines.

H.Filter Section:

1.Standard filter section shall consist of factory- installed, low velocity, throwaway 2-in. thick fiber- glass filters of commercially available sizes.

2.Filter face velocity shall not exceed 320 fpm at nomi- nal airflows.

3.Filter section should use only one size filter.

4.Filters shall be accessible through an access panel with “no-tool” removal.

I.Controls and Safeties:

1.Unit Controls:

Unit shall be complete with self-contained low- voltage control circuit protected by a resettable circuit breaker on the 24-v transformer side.

2.Safeties:

a.Unit shall incorporate a solid-state compressor protector which provides anti-cycle reset capabil- ity at the space thermostat, should any of the following standard safety devices trip and shut off compressor.

1)Compressor overtemperature, overcurrent.

2)Loss-of-charge/low-pressure switch.

3)Freeze-protection thermostat, evaporator coil.

4)High-pressure switch.

5)Automatic reset motor thermal overload protector.

The lockout protection shall be easily discon- nected at the control board, if necessary.

b.Heating section shall be provided with the follow- ing minimum protections:

1)High-temperature limit switches.

2)Overcurrent protection.

c.Unit shall incorporate an outdoor coil defrost system to prevent excessive frost accumulation during heating duty, and shall be controlled as follows:

1)Defrost shall be initiated on the basis of time and coil temperature.

2)A 30/50/90-minute timer shall activate defrost cycle only if the coil temperature is low enough to indicate a heavy frost condition.

3)Defrost cycle shall terminate when defrost thermostats are satisfied and shall have a pos- itive termination time of 10 minutes.

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