Carrier 50TFQ008-012 Product Data page 38

Guide specifications (cont)
L. Special Features:
Certain features are not applicable when the fea-
tures designated by * are specified. For assistance in
amending the specifications, your local Carrier Sales
Office should be contacted.
* 1. Direct Digital Controls:
a. Shall be available as a factory-installed
option.
b. Shall actively monitor all modes of opera-
tion, as well as indoor-fan status, filter status,
indoor-air quality, supply-air temperature,
and outdoor-air temperature.
c. Shall work with Carrier TEMP and VVT®
systems.
d. Shall have built-in diagnostics for thermostat
commands for both staged heating and cool-
ing, indoor-fan operation, and economizer
operation.
e. Shall be equipped with a 5-minute time
delay between modes of operation.
2. Roof Curbs:
a. Formed galvanized steel with wood nailer
strip and capable of supporting entire unit
weight.
b. Allows for installing and securing ductwork
to curb prior to mounting unit on the curb.
* 3. Integrated Economizers:
a. Integrated integral-modulating type capable
of simultaneous economizer and compressor
operation.
b. Includes all hardware and controls to provide
cooling with outdoor air.
c. Equipped with low-leakage dampers not to
exceed 3% leakage at 1.868 mm Hg (1 in.
wg) pressure differential.
d. Capable of introducing up to 100% outdoor
air in both minimum and fully open
positions.
e. Equipped with a gravity relief sliding plate
damper. Damper shall close upon unit shut-
off.
f. Economizer is equipped with 30% of return-
air relief.
g. Designed to close damper during loss-of-
power situations with emergency power
supply.
h. Dry bulb outdoor-air thermostat protection
shall be provided as standard.
i. Economizer is a guillotine-style damper
design.
* 4. 25% Manual Outdoor-Air Damper:
Manual damper package shall consist of
damper, birdscreen, and rainhood which can
be preset to admit up to 25% outdoor air for
year-round ventilation.
* 5. 50% Manual Outdoor-Air Damper:
Manual damper package shall consist of
damper birdscreen, and rainhood which can be
38
preset to admit up to 50% outdoor air for year-
round ventilation.
* 6. 100% Two-Position Damper:
a. Two-position damper package shall include
single blade damper. Admits up to 100%
outdoor air.
b. Damper shall close upon indoor fan shutoff.
c. Designed to close damper during loss of
power situations.
d. Equipped with barometric relief damper.
* 7. 25% Two-Position Damper:
a. Two-position damper package shall include
single blade damper and motor. Admits up
to 25% outdoor air.
b. Damper shall close upon indoor fan shutoff.
c. Designed to close damper during loss of
power situations.
d. Equipped with barometric relief damper.
* 8. Solid-State Enthalpy Control:
a. For use with economizer only.
b. Capable of sensing outdoor-air enthalpy
content (temperature and humidity) and con-
trolling economizer cut-in point to have
minimum heat content air passing over the
indoor coil for
operation.
* 9. Differential Enthalpy Sensor:
a. For use with economizer only.
b. Capable of comparing enthalpy content
(temperature and humidity) of outdoor and
indoor air and controlling economizer cut-in
point at the most economical level.
*10. Electric Resistance Heaters:
a. Open wire nichrome elements with all nec-
essary safety operating controls.
b. UL listed and indicated on basic unit infor-
mative plate.
c. Available in multiples to match heating
requirements.
d. Single point kits available for each heater
when required.
*11. Head Pressure Control Packages:
Consists of solid-state control and outdoor-coil
temperature sensor to maintain condensing
temperature between 32 C (90 F) and 43 C
(110 F) at outdoor ambient temperatures down
to –71 C (0° F) by outdoor fan cycling.
*12. Remote Control Panel:
Panel shall be a decorative, indoor, wall-
mounted panel consisting of:
a. Two-stage heat/2-stage cool thermostat.
b. Automatic changeover.
c. System switch with HEAT-COOL-AUTO.-
OFF settings.
d. Fan switch with ON-AUTO. settings.
e. Ventilation control for remote variation of
the amount of outdoor-air intake.
most efficient system