AAON RN-140 - Manual (Page 71)

71
Startup
(See back of the manual for startup form.)
During startup, it is necessary to perform
routine checks on the performance of the
unit. This includes checking the air flow, air
filters, condenser water flow, dampers,
heaters, and refrigerant charge.
Supply Fans
RN Series units are equipped with direct
drive
backward curved plenum fan
assemblies that are selected to deliver the air
volume specified according to unit size and
job requirements. This is either done with air
volume bands in the blower wheels or with
variable frequency drives. Field airflow
adjustment may be required at startup.
Air volume bands for the wheels are sized
according to the unit’s air delivery
specifications and can also be ordered from
the factory for field installation. Wheels
come standard with a 10% air volume band,
as a safety factor, in case additional air
volume is required from the unit.
Air Flow Adjustment
If reduced air volume is required an air
volume band or larger air volume band can
be installed within the blower wheel to
reduce the amount of air delivered by the
wheel.
If the unit is factory equipped with the air
volume band and additional air volume is
required, the band can be removed from the
wheel.
Use fan program in AAON ECat to
determine the new band size for the required
cfm and static pressure.
The following photos of a wheel are
provided for practical guidelines only in
order to identify the air band location in the
wheel. Actual field installation of the air
band into the wheel will require access into
and through the blower wheel venture,
which may require removal of the blower
motor and wheel.
Air volume bands are made of aluminum,
sized and equipped with easy bend tabs that
are to be inserted into pre-punched slots
provided on the wheel. Once the band has
been inserted into the slots, it MUST BE
secured by bending the tabs over from the
back side of the wheel and also MUST BE
secured from the inside by connecting the
ends together with a pop-rivet in the holes
provided on the ends of the band.
If the band is field installed, a hand held
pop-rivet
tool is recommended for
connecting the band ends together. Caution
must be taken to assure that the band is
tightly installed and no damage, denting or
alteration to the wheel or blades occurs
during the installation.
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
Improper installation, adjustment,
alteration, service or maintenance
can
cause property damage,
personal injury or loss of life. Startup
and service must be performed by a
Factory Trained Service Technician.
WARNING