construction and shall be a quiet series type with a noise level not
exceeding 80 dB (A Scale). The motor frame shall be the standard NEMA
assigned frame size supplied for constant speed use on full voltage, fixed
two phases of the stator windings shall be provided. Motor bearing shall
have minimum L-10 life of 50,000 hours.
2.3.5
Power Factor Capacitors
All motors over 3.7 kW 5 hp shall be provided with power factor correcting
capacitors. Capacitors shall be furnished complete with internal fusing
and bleed-off resistors. Corrected power factor shall be not less than 95
percent at full load. Capacitors shall be installed in enclosures
coordinated with the individual motor construction with leads terminated in
the motor terminal box and identified as capacitor leads. Motor controls
shall have overcurrent device settings properly reduced for the motor and
capacitor combination.
2.3.6
Blower - Motor Base
A full length common base of steel box construction shall be provided for
the blower and drive. The base shall be suitable for direct attachment to
the foundation. Anchor bolts, [anti-vibration strips,] and grout shall be
provided as required for proper installation.
2.3.7
Concrete Foundation
Concrete foundation shall be as indicated. The foundation shall be
entirely separated from the surrounding floor. Concrete shall be as
specified in Section 03300A CAST-IN-PLACE STRUCTURAL CONCRETE.
2.3.8
Filters
**************************************************************************
NOTE: Consult diffuser manufacturers to verify the
percent efficiency required for the diffusers
specified. Use of prefilter blanket increases
filter life.
Delete the last sentence for warm climate projects.
**************************************************************************
Filters shall be [washable dry type,] [disposable dry type,] and shall be
at least 90 percent efficient when tested in compliance with ASHRAE 52.1
dust spot method. Filter shall have at least 0.093 square meter 1 sq. ft
of filter area per 0.0118 cubic meter/second 25 cfm of air flow. Air
filter material shall be polyester felt with 25 mm 1 inch pleat separation.
For filters located outside of the building, a weather hood designed to
keep rain, snow, and other foreign articles away from the filter element
shall be provided. The weather hood shall be designed for inlet velocities
between the hood and the filter element of 2.54 m/second 500 ft/min or
less. A manometer or differential pressure gauge shall be provided on the
filter unit to indicate when the filter element requires cleaning or
replacing. [A filter element by-pass with counter-weighted doors shall be
provided to prevent destruction of the element in the event freezing
moisture clogs the filter].
SECTION 11375A
Page 16
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