PROVEN COMPRESSOR RELIABILITY Ð Design techniques feature computer programmed balance between compressor, condenser, and evaporator. Hermetic (036-150 units) and semi- hermetic (180-300 units) compressors with suction and discharge service valves are equipped with compressor over- current and overtemperature protection to ensure dependability. Crankcase heaters (180-300 units) prevent refrigerant dilution of oil during off cycles and ensure proper lubrication at start-up to prolong compressor life. Crankcase heaters are not neces- sary on 036-150 units due to high-side crankcase design (sizes 072,150) and low refrigerant charge levels (sizes 036-150).

The 579F180 unit (with factory-supplied unloading) is equipped with a thermostatic expansion valve to precisely adjust refriger- ant ¯ow during Stage 1 (unloaded) operation. All other 579F/ 580D units have the exclusive Acutrol™ metering device which precisely controls refrigerant ¯ow, preventing slugging and ¯ood-back, while maintaining optimum unit performance.

Additional unloaders are not recommended on the 579F180- 300 units.

INTEGRATED ECONOMIZERS AND OUTDOOR AIR Ð Optional economizers and manual outdoor-air dampers intro- duce outdoor air which mixes with the conditioned air, improving indoor air quality and often reducing energy consumption.

During a ®rst stage call for cooling, if the outdoor-air tempera- ture is below the control changeover set point, the discharge-air sensor modulates the economizer outdoor-air damper open to achieve the changeover set point. When second-stage cooling is called for, the compressor is energized in addition to the economizer. If the outdoor-air temperature is above the change- over set point, the ®rst stage of compression is activated and the economizer stays at vent position. Economizer operation is controlled by Accusensor™ I dry-bulb thermostat that senses outdoor-air temperature. Accessory upgrade kits include Accu- sensor II solid-state enthalpy control (sizes 036-150) and Accu- sensor III enthalpy sensor.

The Durablade economizer (option or accessory) on the 580D036-150 units has a reliable sliding plate damper which is easily adjusted for 100% outdoor air, 100% return air, or any proportions of mixed air.

The 580D036-150 units can also utilize the optional Parablade economizer. This economizer incorporates a parallel-opposed

blade design with standard enthalpy controls. In addition, the Parablade economizer has a spring return built into the damper motor to provide reliable close-on-power-loss. The Parablade economizer comes equipped with up to 45% barometric relief capability for high outdoor air¯ow applications.

For units without economizer, year-round ventilation is en- hanced by a manual outdoor-air damper (ordered as standard on 579F180-300; ordered as an accessory or an option on 580D036-150 units). The damper can be preset to admit up to 25% outdoor air (sizes 180-300) or 50% outdoor air (sizes 036-150).

In addition, the barometric relief damper or power exhaust accessory can be utilized to help maintain proper building pressure.

INDOOR-AIR QUALITY Ð Sloped condensate pans minimize biological growth in rooftop units in accordance with ASHRAE (American Society of Heating, Refrigeration, and Air Condition- ing Engineers) Standard 62-89. Two-inch ®lters with optional dirty ®lter indicator switch provide for greater particle reduction in the return air. The face-split evaporator coils improve the de- humidi®cation capability of standard units, and standard en- thalpy controls provided with the optional or accessory (sizes 036-150) economizers maximize building humidity control.

TABLE OF CONTENTS

 

Page

Features/Bene®ts

. 1-3

Model Number Nomenclature

. 4,5

ARI Capacity Ratings

. 6,7

Physical Data

. 8-13

Options and Accessories

14-16

Base Unit Dimensions

17-20

Accessory Dimensions

21-24

Selection Procedure

. 25

Performance Data

26-55

Electrical Data

56,57

Typical Piping and Wiring

58,59

Typical Wiring Schematics

60-62

Controls

63,64

Application Data

65,66

Guide Speci®cations

67-72

3

Page 3
Image 3
Bryant 580D manual Table of Contents