Bryant 581A/B manual 252

GUIDE SPECIFICATIONS — 579F/580F180-300 AND 581A155,180 SIZE UNITS (cont)

579F/580F/581A155-300

2.Roof Curbs (Horizontal and Vertical):

a.Formed of 16-gage galvanized steel with wood nailer strip and shall be capable of supporting entire unit weight.

b.Permits installing and securing ductwork to curb prior to mounting unit on the curb.

3.Horizontal Adapter Roof Curb:

Includes factory-assembled adapter and internal duct and substantially improves evaporator fan static performance (static regain).

NOTE: Power exhaust or barometric relief must be mounted in the return ductwork when used in con- junction with this accessory.

*4. Integrated Economizers:

a.Integrated integral modulating type capable of simultaneous economizer and compressor operation.

b.Available as a factory-installed option in vertical supply/return configuration only. (Available as a field-installed accessory for horizontal and/or ver- tical supply return configurations.)

c.Includes all hardware and controls to provide cooling with outdoor air.

d.Equipped with low-leakage dampers, not to exceed 2% leakage at 1 in. wg pressure differential.

e.Capable of introducing up to 100% outdoor air.

f.EconoMi$er IV and EconoMi$er2 shall be equipped with a barometric relief damper.

g.Designed to close damper(s) during loss-of- power situations with spring return built into motor.

h.Dry bulb outdoor-air temperature sensor shall be provided as standard. Outdoor air sensor set point is adjustable and shall range from 40 to 100 F. For the EconoMi$er IV, the return air sensor, indoor enthalpy sensor, and outdoor enthalpy sensor shall be provided as field- installed accessories to provide enthalpy control, differential enthalpy control, and differential dry bulb temperature control. For the EconoMi$er2, the enthalpy, differential temperature (adjustable), and differential enthalpy control shall be provided as field-installed accessories.

i.EconoMi$er IV controller shall use a mixed air thermistor mounted on the evaporator fan hous- ing to control EconoMi$er IV operation to a supply air temperature of 55 F.

j.The EconoMi$er IV and EconoMi$er2 shall have a gear-driven parallel blade design.

k.EconoMi$er IV controller shall provide control of internal building pressure through its accessory power exhaust function. Factory set at 100%, with a range of 0% to 100%.

l.EconoMi$er2 shall be capable of control from a 4 to 20 mA signal through optional 4 to 20 mA design without microprocessor control (required for third party control interface).

m.EconoMi$er IV controller Occupied Minimum Damper Position Setting maintains the minimum airflow into the building during occupied period providing design ventilation rate for full occupancy (damper position during heating). A remote potentiometer may be used to override the set point.

n. EconoMi$er IV controller Unoccupied Minimum Damper Position Setting — The EconoMi$er IV dampers shall be completely closed when the unit is in the occupied mode.

o. EconoMi$er IV controller IAQ/DCV Maximum Damper Position Setting — Setting the maximum position of the damper prevents the introduction of large amounts of hot or cold air into the space. This position is intended to satisfy the base mini- mum ventilation rate.

p.EconoMi$er IV controller IAQ/DCV control modu- lates the outdoor-air damper to provide ventilation

based on the optional 2 to 10 vdc CO2 sensor input.

q.Compressor lockout sensor (opens at 35 F, closes at 50 F).

r.Actuator shall be direct coupled to economizer gear, eliminating linkage arms and rods.

s.Control LEDs:

1)When the outdoor air damper is capable of providing free cooling, the “Free Cool” LED shall illuminate.

2)The IAQ LED indicates when the module is on the DCV mode.

3)The EXH LED indicates when the exhaust fan contact is closed.

t.Remote Minimum Position Control — A field- installed accessory remote potentiometer allows the outdoor air damper to be opened or closed beyond the minimum position in the occupied mode for modified ventilation.

5.Two-Position Damper:

Two-position damper package shall include single blade damper and 24-v motor. Admits up to 25% outdoor air, and shall close upon unit shutoff. Damper shall cover 3.8-in. high by 17.75-in. wide (117.8 sq. in.) opening in return air upper panel.

6. Accessory Compressor Cycle Delay:

Compressor shall be prevented from restarting for a minimum of 5 minutes after shutdown.

*7. Thermostats and Subbases:

To provide staged heating and cooling in addition to automatic (or manual) changeover and fan control.

*8. Barometric Relief Damper Package:

a.Package shall include damper, seals, hardware, and hoods to relieve excess internal pressure.

b.Damper shall close due to gravity upon unit shutdown.

c.Damper package must be field-installed in return- air ductwork when used with optional side return connections.

*9. Power Exhaust:

Package shall include an exhaust (propeller style) fan, 1/2 Hp 208-230, 460 v (factory-wired for 460 v) direct drive motor, and damper for vertical flow units with economizer to control over-pressurization of building. Power Exhaust package must be field- installed in return-air ductwork when used with optional side return connections.

*10. Head Pressure Control Package:

Consists of an accessory outdoor-air package and a solid-state control with condenser coil temperature sensor for controlling condenser-fan motor speed to maintain condensing temperature between 90 F and 100 F at outdoor ambient temperature down to –20 F.

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