Product data

34 Catalog 724-2
Engineering Guide Specication
1.02 SUPPLY FAN
A. Supply fans shall be a DWDI forward-curved
type constructed of 18 ga galvanized steel for
corrosion resistance. Fan housing construction shall
be formed sheet metal. Fan assemblies including
fan, fan housing, and motor shall be dynamically
balanced by the manufacturer on all three planes
at all bearing supports. Manufacturer must ensure
maximum fan RPM is below the rst critical speed
B. The complete fan assembly, including motor and
main drain pan shall be easily removable
C. Units shall be certied in accordance with the
Room Fan Coil Unit certication program that is
based on ARI Standard 440.
1.03 ELECTRICAL
A. Supply fans shall be driven by Permanent-Split
Capacitor high-efciency motor(s) with minimum
of 3-speed taps, permanently lubricated and
run-tested in the assembled unit. All motors shall
have integral thermal overload protection with a
maximum ambient operating temperature of 104°F.
Motors shall be capable of starting at 78 percent of
rated voltage and operating at 90 percent of rated
voltage on all speed settings. Motors can operate up
to 10 percent overvoltage.
B. Motor wires shall include a quick-disconnect motor
plug for easy removal.
C. [Supply fans shall be driven by Electronically-
Commutated motor(s). The ECM motor shall have
ve selectable constant-torque setting controlled by
24VAC input with fully integrated connector and
be run-tested in the assembled unit. The motor to
have 6 kV surge protection.]
1.04 COOLING AND HEATING
A. Cooling Coils
1. Cooling performance shall be as specied on the
unit schedule.
2. Water coil ns shall have full drawn collars
to provide a continuous surface cover over the
entire tube for maximum heat transfer. Seamless
copper tubes shall be mechanically expanded
into the ns to provide a continuous primary-
to-secondary compression bond over the entire
nned length for maximum heat transfer rates.
Copper tubes shall not be visible between ns.
Coil casing shall be constructed of galvanized
steel.
3. Water coils shall be provided with headers of
seamless copper tubing with intruded tube
holes to permit expansion and contraction
without creating undue stress or strain. Coil
connections shall be copper sweat connections
with connection size to be determined by
manufacturer based upon the most efcient coil
circuiting. Vent and drain connections shall be
furnished on the coil connection, external to
the cabinet. Vent connections provided at the
highest point to assure proper venting. Drain
connections shall be provided at the lowest
point.
4. All steel parts exposed to moisture shall be
galvanized.
5. Unit shall include an easily-removable painted
galvanized steel [SS] drain pan, positively
sloped in every plane and insulated with closed-
cell insulation.
6. Vent and drain connections shall be furnished
soldered and installed on the cooling coil by
the coil connection. Vent connections shall be
located at the highest point to ensure proper
venting. Drain connections shall be located at
the lowest point of the coil.
B. [Water/Steam Heating Coil].
1. Heating performance shall be as specied on the
unit schedule.
2. Coil ns shall have full drawn collars to provide
a continuous surface cover over the entire tube
for maximum heat transfer. Seamless copper
tubes shall be mechanically expanded into
the ns to provide a continuous primary-to-
secondary compression bond over the entire
nned length for maximum heat transfer rates.
Copper tubes shall not be visible between ns.
C. [Electric Heating Coils.
1. Auxiliary electric heating coils shall be
provided as the total source of heat [auxiliary
intermediate seasonal heating].
2. The open-wire electric heat coils shall be
located in the preheat position. The electric
heat option shall operate at the same voltage
as the unit [with a separate power supply
voltage to lower amperage rating]. A single
power connection shall be provided when the
unit and electric heat are the same voltage. A
second power connection must be used when
the fan coil and electric heat have different
voltages. All standard electric heat coils shall
be ETL listed and interlocked with the fan
motor switch. Electric heat operation shall be
possible only when the fan is running. A unit-