Bryant 549B - Manual (Page 137)

137
GUIDE SPECIFICATIONS — 549B036-120, 549C024-060 (cont)
3. Compressor with standard controls shall be capable
of operation down to –20 F (in heating mode) ambi-
ent outdoor temperature.
4. Unit shall be capable of simultaneous heating duty
and defrost cycle operation when using accessory
electric heaters.
K. Electrical Requirements:
All unit power wiring shall enter unit cabinet at a single
factory-predrilled location.
L. Motors:
1. Compressor motors shall be cooled by refrigerant
gas passing through motor windings and shall have
line break thermal and current overload protection.
2. Indoor-fan motor shall have permanently lubricated
bearings and inherent automatic-reset thermal over-
load protection.
3. Totally enclosed outdoor-fan motor shall have per-
manently lubricated bearings, and inherent auto-
matic-reset thermal overload protection.
M. Special Features:
Certain features are not applicable when the features
designated * are specified. For assistance in amending
the specifications, contact your local Bryant Sales Office.
1. Roof Curbs (Horizontal and Vertical):
a. Formed galvanized steel with wood nailer strip
and shall be capable of supporting entire unit
weight.
b. Permits installation and securing of ductwork to
curb prior to mounting unit on the curb.
* 2. Integrated Economizers:
a. Integrated integral modulating type capable of
simultaneous economizer and compressor opera-
tion. During economizer operation, up to two
compressors on sizes 090-120 will operate.
b. Available as a factory-installed option in vertical
supply/return configuration only. (Available as a
field-installed accessory for dedicated horizontal
and/or vertical 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$erIV and EconoMi$er2 shall be
equipped with a barometric relief damper capable
of relieving up to 100% return air.
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$erIV, the return air sen-
sor, indoor enthalpy sensor, and outdoor enthalpy
sensor shall be provided as field-installed acces-
sories to provide enthalpy control, differential
enthalpy control, and differential dry bulb temper-
ature control. For the EconoMi$er2, the enthalpy,
differential temperature (adjustable), and differen-
tial enthalpy control shall be provided as field-
installed accessories.
i. The EconoMi$erIV and EconoMi$er2 shall have a
gear-driven parallel blade design.
j. EconoMi$erIV microprocessor control shall pro-
vide control of internal building pressure through
its accessory power exhaust function. Factory set
at 100%, with a range of 0% to 100%.
k. EconoMi$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).
l. EconoMi$erIV Microprocessor Occupied Mini-
mum Damper Position Setting maintains the mini-
mum airflow into the building during occupied
period providing design ventilation rate for full
occupancy (damper position during heating). A
remote potentiometer may be used to override
the set point.
m. EconoMi$erIV Microprocessor Unoccupied Mini-
mum Damper Position Setting — The
EconoMi$erIV damper shall be completely closed
when the unit is in the occupied mode.
n. EconoMi$erIV Microprocessor IAQ/DCV Maxi-
mum 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 minimum ventilation rate.
o. EconoMi$erIV Microprocessor IAQ/DCV control
modulates the outdoor-air damper to provide
ventilation based on the optional 2 to 10 vdc CO
2
sensor input.
p. Compressor lockout sensor (opens at 35 F,
closes at 50 F).
q. Actuator shall be direct coupled to economizer
gear, eliminating linkage arms and rods.
r. 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.
s. Remote Minimum Position Control — A field-
installed accessory remote potentiometer shall
allow the outdoor-air damper to be opened or
closed beyond the minimum position in the occu-
pied mode for modified ventilation.
3. Manual Outdoor-Air Damper:
Manual damper package shall consist of damper,
birdscreen, and rainhood which can be preset
to admit up to 50% outdoor air for year round
ventilation.
* 4. 100% Two-Position Damper:
a. Two-position damper package shall include single
blade damper and motor. Admits up to 100%
outdoor air.
b. Damper shall close upon indoor (evaporator) fan
shutoff.
c. Designed to close damper during loss of power
situations.
d. Equipped with 15% barometric relief damper.
549
B, 5
49C