Liebert EMERSON 60 HZ - Manual (Page 14)

10
G
UIDE
S
PECIFICATIONS
Standard Features for Direct
Drive Propeller Fan
Drycoolers
Furnish and install Liebert Model
________ Air-Cooled Drycoolers,
arranged for vertical air flow. Dry-
coolers shall be draw-through
design and shall perform in accor-
dance with the schedule.
General
Each drycooler shall consist of cas-
ing, drycooler coil, propeller fans
direct-driven by individual fan
motors, fan guards, and mounting
legs.
Fan motors shall be furnished for
operation on a _______ V, ____PH,
______ Hz power supply.
Coil
The drycooler coil shall be con-
structed on copper tubes on a stag-
gered tube pattern. Tubes shall be
expanded into continuous, rippled
aluminum fins. The fins shall have
full-depth fin collars completely
covering the copper tube. Copper
tubes shall be connected to heavy
wall type “L” headers, inlet coil
connector tubes shall pass through
relieved holes in the tube sheet, for
maximum resistance to piping
strain and vibration.
Coils shall be factory leak-tested at
300 PSIG (minimum) dehydrated,
evacuated and sealed.
Casing
The drycooler casing shall be con-
structed of bright aluminum
sheet. Casing shall be divided into
individual fan sections by full
width baffles. Structural support
members, including coil support
frame, motor and drive support
shall be galvanized steel for
strength and corrosion resis-
tance. Aluminum legs with rig-
ging holes shall be provided for
hoisting the unit into position.
Fans
Fans shall have zinc plated steel
or aluminum blades. Fan shall be
secured to fan shaft by means of a
heavy-duty keyed hub and dual
set screws. Fan diameter shall be
30" or less. Fans shall be factory-
balanced and run before ship-
ment.
Fan guards shall be heavy gauge,
close-meshed, steel wire, with cor-
rosion resistant finish.
Fan Motors
Fan motors shall be equipped
with rain slingers and perma-
nently sealed ball bearings.
Motors shall include built-in over-
load protection. Motors shall be
rigidly mounted on die-formed
galvanized steel supports.
Quiet-Line Motors
Fan motors shall be 12-pole,
570 rpm, equipped with rain
shields and permanently sealed
ball bearings. Motors shall
include built-in overload protec-
tion. Motors shall be rigidly
mounted on die-formed galva-
nized steel supports.
Electrical Control
All electrical connections (and
electrical low ambient control
options) shall be provided in
weatherproof enclosure. The
enclose shall be integral with the
drycooler for pleasing appearance
as well as functional protection.
The base model (DNC) shall have
the motor(s) factory wired to a
three phase power block in the
electrical enclosure. Main electri-
cal control model (DNL) provides
magnetic contactor and control
voltage for remote starting of the
drycooler.
The drycooler shall be provided
with optional disconnect switch
mounted and wired.
Fan cycling model (DNT) shall be
used to control leaving fluid tem-
perature by cycling fans in one or
two steps. The 24 volt control cir-
cuit furnished, consists of control
transformer, fan contactor(s) and
temperature controls) as speci-
fied.
Fan cycling with pump control
model (DSO)-single pump, (DDO)-
dual pump shall have the features
as the fan cycling model plus
starter(s) for the pump(s) and a
built-in disconnect switch.