Trane 7½ - 20 Tons Manual page 61

Mechanical Specifications
and vibration to building structures,
equipment and adjacent spaces.
Packages shall be available in either
neoprene-in-shear or spring-flex
types.
Time Delay Relay — Shall prevent
compressors in dual compressor unit
from coming on line simultaneously.
Timer shall be 24-volt, 60 cycle, with
four minute timing period.
Anti-Short-Cycle Timer — Shall
prevent rapid on-off compressor
cycling in light load conditions by not
allowing compressor to operate for
5-7 minutes upon shutdown. Shall
consist of a solid state timing device,
24-volt, 60 cycle with either 5 or 7
minute fixed-off timing period.
Condenser Coil Guard — Metal
grille with PVC coating shall be
provided to alleviate coil damage.
Black Epoxy Coated Condenser
Coil — The black epoxy coils have a
thermoset vinyl coating that is
bonded to the aluminum fin stock
prior to the fin-stamping process.
The pre-coated coils are an
economical option for protection in
mildly corrosive environments.
Air Handlers
General
Air handler units shall be completely
factory assembled including coil,
condensate drain pan, fan motor(s),
filters and controls in an insulated
casing that can be applied in either
vertical or horizontal configuration.
Units shall be rated and tested in
accordance with ARI standard 340/
360. Units shall be UL listed and
labeled in accordance with UL 1995
for indoor blower coil units.
Casing
Unit casing shall be constructed of
zinc coated, heavy gauge, galvanized
steel. Exterior surfaces shall be
cleaned, phosphatized and finished
with a weather-resistant baked
enamel finish. Casing shall be
completely insulated with cleanable,
foil faced, fire-retardant, permanent,
odorless glass fiber material. All
insulation edges shall be either
captured or sealed. Knockouts shall
be provided for unit electrical power
and refrigerant piping connections.
SSP-PRC001-EN
Captive screws shall be standard on
all access panels.
Refrigeration System
The TWE060A, TWE090A, TWE120A
units shall have a single refrigeration
circuit and the TWE060B, TWE090B,
TWE120B, TWE180B, TWE240B units
shall have dual refrigeration circuits.
Each refrigeration circuit is controlled
by a factory installed thermal
expansion valve.
Evaporator Coil
Configured aluminum fin surface
shall be mechanically bonded to 3/8"
internally enhanced copper tubing
and factory pressure and leak tested
at 375 psig. Coil is arranged for draw-
through airflow and shall provide a
double sloped condensate drain pan
constructed of PVC plastic. The drain
pan shall be removable for cleaning.
The condensate drain pan can be
installed in any of four positions
allowing for vertical or horizontal
application and providing external
connections on either side of the
unit.
Evaporator Fan
Double inlet, double width, forward
curved, centrifugal-type fan(s) with
adjustable belt drive shall be
standard. Thermal overload
protection shall be standard on
motor. Fan and motor bearings shall
be permanently lubricated. Oversized
motors shall be available as an
option for high static application. All
indoor fan motors meet the U.S.
Energy Policy Act of 1992 (EPACT)
Controls
Magnetic evaporator fan contactor,
low voltage terminal strip, check
valve(s), and single point power
entry shall be included. All necessary
controls shall be factory-installed and
wired. Evaporator defrost control
shall be included to prevent
compressor slugging by temporarily
interrupting compressor operation
when low evaporator coil
temperatures are encountered.
Filters
One inch, throw-away filters shall be
standard on TWE060A, TWE090A,
TWE060B, TWE090B and TWE120B
model air handlers. Filters shall be
accessible from the side coil access
panel. Filter rack can be field
converted to two inch capability. Two
inch, throw-away filters shall be
standard on TWE180B and TWE240B
models.
Accessories
Electric Heaters — UL and CSA
approved electric heat modules shall
be available for installation directly
on fan discharge. Electric Heaters
shall be available in a wide range of
capacities with one or two stage
control, single-point electric power
connection and terminal strip
connections. Electric heater elements
shall be constructed of heavy-duty
nickel chromium elements internally
wye connected on 480/600 volt, three
phase and delta connected on 208/
240 volt, three phase. Each 208/240
volt heater shall have pilot duty with
secondary backup fuse links for
automatic reset of high limit controls.
Each 480/600 volt heater shall have
automatic line break high limit
controls.
Discharge Plenums and Grilles —
Accessory discharge plenums shall
be available for vertical, free
discharge applications. Plenums shall
be constructed of heavy-gauge, zinc
coated galvanized steel finished with
baked enamel to match the air
handler unit. Grilles shall be satin
finished aluminum and have four-
way adjustable louvers.
Return Air Grilles — Accessory
return air grille shall be provided for
vertical front, free return
applications. Grilles shall be installed
in place of the front lower side panel.
Grille shall be satin finished
aluminum with non-adjustable
louvers.
Mounting Subbase — Available for
vertical floor mount configurations.
Subbase shall be constructed of
heavy gauge, zinc coated galvanized
steel with baked enamel finish to
match air handler unit. Subbase is
required in the vertical air flow
application for condensate drain
trapping and when isolators are
required.
Vibration Isolators — Shall reduce
transmission of noise and vibration
to building structures, equipment
and adjacent spaces. Packages shall
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