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GUIDE SPECIFICATIONS — 579F/580F180-300 AND 581A155,180 SIZE UNITS (cont)
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% ou tdoor 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 sup-
ply 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$er IV controller Occupied Minimum
Damper Position Setting maintains the minimum
airflow into the building during occupied period
providing design ventilation rate for full occu-
pancy (damper position during heating). A remote
potentiometer may be used to override the set
point.
n. EconoMi$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.