Bryant 549B - Manual (Page 70)

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GUIDE SPECIFICATIONS — 548F036-120 (cont)
c. E-Coated copper-fin coils shall have a flexible
epoxy polymer coating uniformly applied to all coil
surface areas without material bridging between
fins. Coating process shall ensure complete coil
encapsulation. Color shall be high gloss black
with gloss — 60 deg of 65 to 90% per ASTM
D523-89. Uniform dry film thickness from 0.8 to
1.2 mil on all surface areas including fin edges.
Superior hardness characteristics of 2H per
ASTM D3363-92A and cross-hatch adhesion of
4B-5B per ASTM D3359-93. Impact resistance
shall be up to 160 in./lb (ASTM D2794-93).
Humidity and water immersion resistance shall be
up to minimum 1000 and 250 hours respectively
(ASTM D2247-92 and ASTM D870-92). Corro-
sion durability shall be confirmed through testing
to be no less than 1000 hours salt spray per
ASTM B117-90. Coil construction shall be copper
fins mechanically bonded to copper tubes with
copper tube sheets. Galvanized steel tube sheets
shall not be acceptable. A polymer strip shall pre-
vent coil assembly from contacting sheet metal
coil pan to maintain coating integrity and minimize
corrosion potential between coil and pan.
d. Optional pre-coated aluminum-fin coils shall have
a durable epoxy-phenolic coating to provide pro-
tection in mildly corrosive coastal environments.
Coating shall be applied to the aluminum fin stock
prior to the fin stamping process to create an inert
barrier between the aluminum fin and copper
tube. Epoxy-phenolic barrier shall minimize gal-
vanic action between dissimilar metals.
F. Refrigerant Components: Refrigerant circuit components
shall include:
1. Fixed orifice multiple independent circuit metering
system.
2. Service gage connections on suction, discharge, and
liquid line to charge, evacuate, and contain
refrigerant.
3. Accumulator.
4. Reversing valve.
G. Filter Section:
1. Standard filter section shall consist of factory-
installed low-velocity, throwaway 2-in. thick fiberglass
filters of commercially available sizes.
2. Filter face velocity shall not exceed 300 fpm at nomi-
nal airflows.
3. Filter section shall use only one size filter.
4. Filters shall be accessible through an access panel
with ‘‘no-tool’’ removal.
H. Controls and Safeties:
1. Unit Controls:
a. Unit shall be complete with self-contained low-
voltage control circuit.
b. Unit shall incorporate an outdoor coil defrost
system to prevent excessive frost accumulation
during heating duty, and shall be controlled as
follows:
1) Defrost shall be initiated on the basis of time
and coil temperature.
2) A 30/50/90-minute timer shall activate defrost
cycle only if coil temperature is low enough to
indicate a heavy frost condition.
3) Defrost cycle shall terminate when defrost
thermostat is satisfied and shall have a positive
termination time of 10 minutes.
c. Unit shall contain high-pressure, loss-of-charge/
low-pressure, and freeze protection switches. It
shall mount on factory-installed Schrader fittings.
2. Standard Safeties:
Unit shall incorporate compressor overtemperature
and overcurrent safety devices to shut off
compressor.
I. Operating Characteristics:
1. Unit shall be capable of starting and running in cool-
ing at 115 F ambient outdoor temperature, meeting
maximum load criteria of ARI Standard 210/240 at
±10% voltage.
2. Compressor with standard controls shall be capable
of cooling operation down to 25 F ambient outdoor
temperature.
3. Compressor shall be capable of operation in heating
duty down to –10 F ambient outdoor-air temperature.
4. Unit shall be capable of simultaneous heating duty
and defrost cycle operation when using electric heat-
ers indicated in Section L, Special Features.
J. Electrical Requirements:
All unit power wiring shall enter unit cabinet at a single
factory-predrilled location.
K. Motors:
1. Compressor motors shall be cooled by refrigerant
passing through motor windings and shall have line
break thermal and current overload protection.
2. Indoor blower motor shall have permanently lubri-
cated bearings and inherent automatic-reset thermal
overload protection.
3. Totally enclosed outdoor-fan motor shall have
permanently lubricated bearings, and inherent
automatic-reset thermal overload protection.
L. Special Features:
Certain features are not applicable when the features
designated by * are specified. For assistance in amend-
ing the specifications, your local Bryant Sales Office
should be contacted.
1. 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.
* 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.
548
F