The IGC also contains burner control logic for accurate and dependable gas ignition. The LED is visible without removing the unit control box access panel. This LED fault-noti®cation system reduces service person troubleshooting time and mini- mizes service costs. The IGC also maximizes heating ef®ciency by controlling evaporator-fan on and off delays.
QUIET, EFFICIENT OPERATION AND DEPENDABLE PER- FORMANCE Ð Compressors have vibration isolators for ex- tremely quiet operation. Ef®cient fan and motor design permits operation at very low sound levels and all 580D036-150 units are mounted either on independent mounting rails (036-072) or on an exclusive polycore plate (090-150).
The 580D090-150 and 579F180-300 units offer high energy ef- ®ciency and lower utility costs through part-load operation using 2 stages of cooling.
Quiet and ef®cient operation is provided by belt-driven evapo- rator fans (standard on all units over 5 tons). The belt-driven evaporator-fan is equipped with variable-pitch pulleys which al- low adjustment within the rpm ranges of the factory-supplied pulleys.
A standard (low-medium static) and alternate (high static) drive is available for 579F180-300 units.
Increased operating ef®ciency is achieved through computer- designed coils featuring staggered internally enhanced copper tubes. Fins are ripple-edged for strength, lanced, and double waved for higher heat transfer.
Tubular, dimpled gas heat exchangers optimize heat transfer for improved ef®ciency. The tubular design permits hot gases to make multiple passes across the path of the supply air. The dimpled design creates a turbulent gas ¯ow to maximize heating efficiency. The extra thick Alumagard™ heat exchanger coating provides corrosion resistance and ensures long life.
The California Air Quality Management Districts NOx require- ment of 40 nanograms/joule or less is met when low NOx kit CRLOWNOX001A00 is installed for sizes 036-060.
The unsightly appearance of ¯ue stacks is eliminated and the effects of wind on heating operations are diminished by the in- duced draft combustion system. The inducer fan draws hot combustion gas through the heat exchanger at the optimum rate for the most effective heat transfer. The heat exchanger oper- ates under negative pressure, preventing ¯ue gas leakage into the indoor supply air.
During the heating mode, the evaporator-fan relay automatically starts the evaporator fan after the heat exchanger warms up to a suitable temperature. The 30-second fan delay prevents cold air from entering the supply duct system when the conditioned space is calling for heat to maximize efficiency.
The direct-spark ignition system saves operating expense when compared to pilot ignition systems. No crossover tube is re- quired, therefore no sooting or pilot fouling problems can occur.
All 580D and 579F standard units are designed for natural gas, but an accessory LP (liquid propane) conversion kit is available, if required.
SAFETY IS BUILT IN Ð All 580D and 579F units have a ¯ame recti®cation sensor to quickly sense the burner ¯ame and ignite burners almost immediately. Fast shutdown is a certainty since the sensor reacts quickly to any ¯ame outage or system failure. In the event of a shutdown, an error code is issued at the IGC board.
Safety is also assured due to the heating safety controls which will shut down the unit if there is a problem. If excessive tem- peratures develop, limit switches shut off the gas valve. After 4 continuous short cycles of the high-temperature limit switch, the IGC board locks out the gas heat cycle to prevent any further short cycles. This safety feature is provided exclusively on Bryant rooftop units. The rollout switch also deenergizes the gas valve in the event of a ¯ame rollout.
DURABLE, DEPENDABLE CONSTRUCTIONÐ Designed for durability in any climate, the weather-resistant cabinets are con- structed of galvanized steel and bonderized, and all exterior panels are coated with a prepainted baked enamel ®nish. The paint ®nish is non-chalking, and is capable of withstanding ASTM B117 500-hour Salt Spray Test. All internal cabinet pan- els are primed, permitting longer life and a more attractive ap- pearance for the entire unit.
In addition, the 580D090-150 units are designed with a single, continuous top piece to eliminate any possible leaks. Totally- enclosed condenser-fan motors and permanently-lubricated bearings provide additional unit dependability.
EASY INSTALLATION AND CONVERSION Ð All units are shipped in the vertical discharge con®guration for ®t-up to stand- ard roof curbs. (Two different curb sizes ®t unit sizes 036-072 and 090-150, respectively, and one curb size is needed for 180- 300 units.) The contractor can order and install the roof curb early in the construction stage, before decisions on size require- ments are made.
All units feature roll-formed baserail design with forklift slots and rigging holes for easier maneuvering. (Forklift slots are found on 3 sides for 580D036-150 units and on 2 sides for 180-300 units.) The standard 580D036-060 units have operating weights under 500 lb and durable packaging protects all units during shipment and storage.
The units can be easily converted from a vertical to a hori- zontal discharge con®guration either by interchanging the panels supplied with the unit (sizes 036-150) or by using one of the horizontal supply/return adapter roof curbs (sizes 180-300).
NOTE: On units using horizontal supply and return the acces- sory barometric relief or power exhaust must be installed on the return ductwork.
Convenient duct openings in the 579F180-300 unit basepans permit side-by-side or concentric duct connections (see Applica- tion data section on page 65) without requiring internal unit modi®cation.
The non-corrosive sloped condensate pan permits either an ex- ternal horizontal side condensate drain (outside the roof curb) or an internal vertical bottom drain (inside the roof curb). Both op- tions require an external, ®eld-supplied P-trap. Also, the con- denser coil grille (available on the 036-150 units as a ®eld- installed accessory provides a metal plate as an alternate location for the ®eld-supplied disconnect, if desired.
The 579F/580D units were designed with service technicians in mind. The single-row condenser coils on the 580D036-060 and 090 units simplify the cleaning process. The ef®cient in-shot burners and all ignition components are contained in an easily removable, compact assembly.
The 580D036-150 units also have a standard ®lter access panel, which permits tool-less ®lter changes, even on units with horizontal economizers.
SIMPLE ELECTRICAL CONNECTIONS Ð Terminal boards, located in the base unit control box, facilitate connections to room thermostat, outdoor thermostat(s), and economizer. Serv- ice panels are quickly removed, permitting easy servicing.
Thru-the-bottom service connection capability (sizes 036-150) and thru-the-curb service connections (sizes 180-300) allow power and control wiring to be routed through unit base pan (036-150 units) or curb (180-300 units), minimizing roof pen- etrations. Both power and control connections are made on the same side of the unit to simplify installation.
In addition, color-coded wires permit easy tracing and diagnostics.
