First Co EVBQ (Variable Speed) - Manual (Page 4)

PROCEDURE 3 – AIR DUCTS
All duct work must be installed in accordance with National Fire Protection Association Codes 90A and 90B.
In many cases it is acceptable to use ducting of the same size as the fan coil connections. However, unique arrangements or
long duct runs must be confirmed by a local professional. The manufacturer will not be responsible for misapplied equip-
ment.
It is recommended to use flexible connectors between ductwork and the fan coil unit to prevent transmission of vibration.
Connect supply-air duct over outside of flanges provided on supply-air opening. Secure duct to flange with proper
fasteners for type of duct used, and seal duct-to-unit joint. Ducts should be adequately insulated to prevent condensation
during the cooling cycle and to minimize heat loss during the heating cycle.
All return air must be filtered to prevent dirt buildup on the coil surface. If there is no ducted return, applicable installation codes
may limit the unit to installation only in a single story residence.
Ductwork Acoustical Treatment
Metal duct systems that do not have a 90 degree elbow and 10 ft. of main duct to first branch takeoff may require internal
acoustical insulation lining. As an alternative, fibrous ductwork may be used if constructed and installed in accordance with
the latest edition of SMACNA construction standard on fibrous glass ducts. Both acoustical lining and fibrous ductwork
shall comply with National Fire Protection Association Standards 90A or 90B as tested by UL Standard 181 for Class 1 air
ducts.
PROCEDURE 4 – ELECTRICAL CONNECTIONS
NOTE: Before proceeding with electrical connections, make certain that supply voltage, frequency, and phase are as
specified on unit rating plate. Be sure that electrical service provided by the utility is sufficient to handle the additional load
imposed by this equipment. See unit wiring label for proper field high and low voltage wiring. Make all electrical connec-
tions in accordance with NEC and any local codes or ordinances that may apply. Use copper wire only. The unit must have
a separate branch electric circuit with a field supplied disconnect switch located within sight of and readily accessible from
the unit.
CAUTION: If a disconnect switch is to be mounted on the unit, select a location where drill or fastener will
not contact electrical or refrigerant components. Electrical shock can cause personal injury or death.
WARNING: Service and maintenance to internal components and wiring can not be performed until the
main disconnect switch (remote to the unit) is turned off. Failure to do so will result in electrical shock
causing personal injury or death.
A. Line-Voltage Connections
Connect 120V power leads from field disconnect to white and black stripped leads.
Connect ground wire to unit ground lug.
Check all factory wiring per unit wiring diagram and inspect factory wiring connections to be sure none were loosened in
transit or installation.
B. Ground Connections
WARNING: The cabinet must have an uninterrupted or unbroken ground according to NEC, ANSI/NFPA 70
and local codes to minimize personal injury if an electrical fault should occur. The ground may consist of
electrical wire or metal conduit when installed in accordance with existing electrical codes. (See Ground/
Conduit Note below.) Failure to follow this warning could result in an electrical shock, fire, or death.
NOTE: Use UL listed conduit and conduit connector to connect supply wire(s) to unit and obtain proper grounding. If
conduit connection uses reducing washers, a separate ground wire must be used. Grounding may also be accomplished by
using grounding lug provided in control box.
C. 24V Control System Connections to Unit Circuit Board
Refer to unit wiring diagram for recommended wiring procedures. Use No. 18 AWG color-coded, insulated (35 degrees C
minimum) wires to make low-voltage connections between thermostat and unit. If thermostat is located more than 100 ft.
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