Bryant LEGACY 580J - Manual (Page 58)

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l. The economizer shall maintain minimum airflow into the building during occupied period and provide design
ventilation rate for full occupancy. A remote potentiometer may be used to override the damper setpoint.
m. Dampers shall be completely closed when the unit is in the unoccupied mode.
n. Economizer controller shall accept a 2--10Vdc CO
2
sensor input for IAQ/DCV control. In this mode, dampers
shall modulate the outdoor--air damper to provide ventilation based on the sensor input.
o. Compressor lockout sensor shall open at 35_F (2_C) and close closes at 50_F (10_C).
p. Actuator shall be direct coupled to economizer gear. No linkage arms or control rods shall be acceptable.
q. Economizer controller shall provide indications when in free cooling mode, in the DCV mode, or the exhaust
fan contact is closed.
2. Two--Position Motorized Damper
a. Damper shall be a Two--Position Damper. Damper travel shall be from the full closed position to the field ad-
justable %--open setpoint.
b. Damper shall include adjustable damper travel from 25% to 100% (full open).
c. Damper shall include single or dual blade, gear driven dampers and actuator motor.
d. Actuator shall be direct coupled to damper gear. No linkage arms or control rods shall be acceptable.
e. Damper will admit up to 100% outdoor air for applicable rooftop units.
f. Damper shall close upon indoor (evaporator) fan shutoff and/or loss of power.
g. The damper actuator shall plug into the rooftop unit’s wiring harness plug. No hard wiring shall be required.
h. Outside air hood shall include aluminum water entrainment filter.
3. Manual damper
a. Manual damper package shall consist of damper, air inlet screen, and rain hood which can be preset to admit
up to 25% outdoor air for year round ventilation.
4. Perfect Humidity Adaptive Dehumidification System:
a. The Perfect Humidity Dehumidification System shall be factory installed and shall provide greater
dehumidification of the occupied space by two modes of dehumidification operations in addition to its normal
design cooling mode:
(1.) Subcooling mode further sub cools the hot liquid refrigerant leaving the condenser coil when both temperat-
ure and humidity in the space are not satisfied.
(2.) Hot gas reheat mode shall mix a portion of the hot gas from the discharge of the compressor with the hot
liquid refrigerant leaving the condenser coil to create a two--phase heat transfer in the system, resulting in a
neutral leaving air temperature when only humidity in the space is not satisfied.
(3.) Includes head pressure controller.
5. Head Pressure Control Package
a. Controller shall control coil head pressure by condenser--fan speed modulation or condenser--fan cycling and
wind baffles.
b. Shall consist of solid--state control and condenser--coil temperature sensor to maintain condensing temperature
between 90_F (32_C) and 110_F (43_C) at outdoor ambient temperatures down to --20_F (--29_C).
6. Propane Conversion Kit
a. Package shall contain all the necessary hardware and instructions to convert a standard natural gas unit for use
with liquefied propane. Kits shall be available for elevations from 0 up to 14,000 ft (4,276m).
7. Condenser Coil Hail Guard Assembly
a. Shall protect against damage from hail.
b. Shall be louvered style design.
8. Unit--Mounted, Non--Fused Disconnect Switch:
a. Switch shall be factory--installed, internally mounted.
b. National Electric Code (NEC) and UL approved non--fused switch shall provide unit power shutoff.
c. Shall be accessible from outside the unit.
d. Shall provide local shutdown and lockout capability.
9. Convenience Outlet:
a. Powered convenience outlet.
(1.) Outlet shall be powered from main line power to the rooftop unit.
(2.) Outlet shall be powered from line side of disconnect by installing contractor, as required by code. If outlet
is powered from load side of disconnect, unit electrical ratings shall be UL certified and rated for addi-
tional outlet amperage.
(3.) Outlet shall be factory--installed and internally mounted with easily accessible 115--v female receptacle.
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