TEMPMASTER
72
FORM TPM3-EG1 (518)
Evaporator Section
1.
Cooling Coil:
Evaporator coils shall be DX type with intertwined circuiting to assure
complete coil face activity during part load operation. Coil tubes shall be 1/2-inch
outside diameter (OD) copper with internally enhanced tubes. Fins shall be en-
hanced mechanically, expanded to bond with the copper tubes. Coil casing shall be
fabricated from heavy gauge galvanized steel. All coils shall be pressure-tested at
a minimum of 450 psig.
2.
Indoor Air Quality (IAQ) Drain Pan:
The main coil drain pan shall be double-
sloped of stainless steel construction with a condensate connection through the
base rail of the unit. Clearance between the evaporator coil and the drain pan shall
allow for easy access to the drain pan for cleaning and shall be visible for inspection
without the removal of components.
3.
Intermediate Drain Pan:
Coils with finned height greater than 48 inches shall have
an intermediate drain pan extending the entire finned length of the coil. The interme
-
diate pans shall have drop tubes to guide condensate to the main drain pan.
Supply Fan Section
1.
Fan:
The fan section shall be equipped with a single DWDI airfoil type wheel for
horizontal discharge. An access door shall be provided on both sides of the unit for
fan/motor access.
a. Mountings:
Fan and fan motor shall be internally mounted and isolated on a full
width isolator support channel using 1-inch springs [2-inch springs and seismic
restraints optional]. The fan discharge shall be connected to the fan cabinet us-
ing a flexible connection to ensure vibration-free operation.
b. Bearings and Drives:
Fan bearings shall be self-aligning, pillow block, or
flanged type regreaseable ball bearings and shall be designed for an average
life (L50) of at least 200,000 hours. All bearings shall be factory lubricated and
equipped with standard hydraulic grease fittings and lube lines extended to the
motor side of the fan. Fan drives shall be selected for a 1.5 service factor and
anti-static belts shall be furnished. All drives shall be fixed pitch. Fan shafts shall
be selected to operate well below the first critical speed and each shaft shall be
factory coated after assembly with an anti-corrosion coating.
c.
Optional Variable Frequency Drive (VFD) Manual Bypass:
A three contactor
manual bypass shall be provided to permit replacement of the VFD in the event
of a power failure.
2.
Direct Drive Plenum (DDP) Supply Fan:
The fan section shall be equipped with
two SWSI airfoil plenum wheels. Plenum fans shall be direct drive. An access door
shall be provided on both sides of the unit for fan/motor access.
a. Mountings:
Fan and fan motor shall be internally mounted and isolated on a full
width isolator support channel using 1-inch springs [2-inch springs and seismic
restraints optional].
b.
Acoustiweir
™
:
Unit shall include a discharge air (DA) sound attenuation barrier.
The passive sound attenuator barrier shall be mounted on the downstream side
of the supply fan and shall block line-of-sight between the fan and the unit dis-
charge opening. If not available, manufacturer must provide a sound attenuator
of at least 3 feet in length.
Guide Specifications (Cont'd)