Bryant 581A/B manual Features/Benefits

FEATURES/BENEFITS (cont)

The units can be easily converted from a vertical to a horizontal duct configuration by relocating the panels supplied with the unit (size 036-150 only).

To Convert 036-151 Units from vertical to horizontal discharge, simply relocate 2 panels. The same basic unit can be used for a variety of applications and can be quickly modified at the job- site.

To Convert 155-300 Units from vertical to horizontal discharge, use the optional horizontal supply/return adapter roof curb (581A155,180 and 579F/580F180-300) or accessory conversion kit (581A210-300). Please note that 581A210-300 units are available from the factory configured for horizontal supply/return.

Convenient Duct Openings in the unit basepans permit side- by-side or concentric duct connections (see Application data section) without requiring internal unit modification.

NOTE: On units using horizontal supply and return, the acces- sory barometric relief or power exhaust MUST be installed on the return ductwork.

Thru-The-Bottom Service Connection Capability comes standard with the rooftop unit to allow power and control wiring and gas connections to be routed through the unit’s basepan, thereby minimizing roof penetrations (to prevent water leaks). (Thru-the-bottom gas connection requires thru-the-bottom accessory kit.) Power, gas and control connections are made on the same side of the unit to simplify installation.

The Non-Corrosive Sloped Condensate Drain Pan (Size 036-150) permits either an external horizontal side con- densate drain (outside the roof curb) or an internal vertical bottom drain (inside the roof curb). Both options require an external, field-suppliedP-trap.

Standard 2-in. Throwaway Filters are easily accessed through a removable panel located above the air intake hood. No tools are required to change unit filters.

Belt-Driven Evaporator-Fan Motors (optional on 580F units under 6 tons) allow maximum on-site flexibility without changing motors or drives.

Low Voltage Wiring Connections are easily made thanks to the large terminal board which is located for quick, convenient access.

In addition, color-coded wires permit easy tracing and diagnostics.

PROVEN COMPRESSOR RELIABILITY — Design techniques feature computer-programmed balance between compressor, condenser, and evaporator. Bryant-specified hermetic compres- sors are equipped with compressor overcurrent and overtem- perature protection to ensure dependability.

All units have Bryant’s exclusive Acutrol™ (036-150) or TXV (thermostatic expansion valve) metering device (155-300) which precisely controls refrigerant flow, preventing slugging and flood-back, while maintaining optimum unit performance. Refrigerant filter driers are standard.

INTEGRATED ECONOMIZERS AND OUTDOOR-AIR DAMP- ERS — Available as options or accessories, economizers and manual outdoor-air dampers introduce outdoor air which mixes with the conditioned air, improving indoor-air quality and often reducing energy consumption.

During a first stage call for cooling, if the outdoor-air tempera- ture is below the economizer control changeover set point, the mixed-air sensor modulates the economizer outdoor-air damper open to take advantage of free cooling provided by the outside air. When second-stage cooling is called for, the compressor is energized in addition to the economizer. If the outdoor-air tem- perature is above the changeover set point, the first stage of compression is activated and the economizer damper stays at minimum position.

Accessory upgrade kits allow for control by differential dry-bulb temperature (outdoor vs return), outdoor air enthalpy changeover, or more precise differential enthalpy control.

Units can be equipped with different economizer options to meet specific controls applications. The factory-installed or field-installed EconoMi$er IV and EconoMi$er2 are available. The EconoMi$er IV is used with the standard rooftop unit con- trols and includes an industry standard, stand-alone, solid-state controller. The control can be used with a CO2 sensor for DCV (demand control ventilation) operation. For direct digital control (DDC) applications, the EconoMi$er2 can be operated using a third party control system. The EconoMi$er2 includes 4 to 20 mA actuator capability for demand control ventilation applications.

All economizers incorporate a parallel blade, gear-driven damper system for efficient air mixing and reliable control. In addition, the standard damper actuator includes a spring return to provide reliable closure on power loss. The economizers for sizes 036-151 are equipped with up to 100% barometric relief capability for high outdoor airflow operations. Economizers for unit sizes 036-151 are available, factory-installed, for vertical return only. Economizers for unit sizes 155-300 are compatible for vertical or horizontal return. An optional field-installed baro- metric relief package is available for size 155-300 units.

In addition, single-stage power exhaust is available as a field- installed accessory for EconoMi$er IV to help maintain proper building pressure.

For units without economizer, year-round ventilation is enhanced by an optional manual outdoor-air damper. On 036- 150 units, a 25% or 50% manual damper is available as a field- installed accessory. Unit sizes 155-300 are equipped with a manual 25% damper.

SERVICE OPTIONS (581B and 581A Units Only) — Servicing a rooftop unit has never been easier with the factory-installed service options for these rooftop units. These options include the following:

•Hinged access panels are provided for the filter/indoor-fan motor, compressors, evaporator fan, and control box areas. Quick access to major components is accomplished by simply unlatching and swinging open the various panels. Each hinged panel is permanently mounted to the unit, thereby eliminating the concern of a dropped or wind-blown panel puncturing delicate roof materials. The 4 extended access panels are also equipped with ‘‘tie back’’ retaining devices to hold the door in the open position while servicing the unit.

•An external, covered, 115-v Ground Fault Interrupt (GFI) receptacle is provided as a convenient power source for drills, lights, refrigerant recovery units, or other electrical service tools. A factory-supplied step down transformer is connected to the “load” side of the unit main power connection (size 036- 150). For sizes 155-300, connect the outlet to a field-supplied and properly fused branch circuit power supply.

•Slide out “motor-drive-blower” reduces service time (only on 581A210-300).

•An integral non-fused disconnect switch within the rooftop unit reduces installation time, labor and material costs. Safety is assured by an interlock which prevents access to the control box unless the switch is in the OFF position. In addition, the externally mounted handle incorporates power lockout capa- bility to further protect service personnel.

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