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507232-04 7/2017
4- Referring to Page 22 and Page 23, use static pressure
and RPM readings to determine unit CFM. Use
Page 28 when installing the unit in horizontal air
discharge applications. Use Page 29 when installing
units with any of the optional accessories listed.
5- The blower RPM can be adjusted at the motor pulley.
Loosen Allen screw and turn adjustable pulley clockwise
to increase CFM. Turn counterclockwise to decrease
CFM. See figure 30 and 25.
Loosen both Allen screws on units equipped with two
belts. Remove the key and turn the inner sheave the
opposite direction of the outer sheave. Replace the key
before securing Allen screws.
PULLEY ADJUSTMENT
TO INCREASE CFM
LOOSEN ALLEN SCREW &
TURN PULLEY CLOCKWISE
TO DECREASE CFM
TURN PULLEY
COUNTERCLOCKWISE
PULLEY
MOTOR
ALLEN
SCREW
SIDE VIEW
FIGURE 30
Note - Pulley minimum number of turns open:1.
Maximum number of turns open: 6.
OUTER SHEAVE
MOTOR
ALLEN
SCREWS
INNER SHEAVE
UNITS EQUIPPED WITH TWO BELTS:
LOOSEN BOTH ALLEN SCREWS AND REMOVE
KEY. TURN INNER SHEAVE THE OPPOSITE DI
RECTION OF THE OUTER SHEAVE. REPLACE
KEY BEFORE SECURING ALLEN SCREWS
6-Variable Air Volume Supply Air Blowers -
In addition to adjusting the motor pulley, the supply
CFM can be adjusted at the Unit Controller or by using
optional software. The VFD must be set to 60Hz. Refer
to the Unit Controller manual parameter 390.
In default mode, the Unit Controller is set to drive the
blower to maximum CFM output (100% or 60Hz). To
decrease the CFM, reduce the VAV maximum output
parameter 390. If the CFM needs to be increased
beyond the motor pulley's capacity at 60Hz, refer to the
drive kit options in this manual to see if there may be a
different drive kit available to increase CFM.
The default minimum blower output is 50% (30Hz).
Refer to parameter 27 and 28 to adjust the VAV
minimum output.
E-Optional Power Exhaust Blowers
1-Determine the power exhaust CFM in the same manner
as the supply CFM with one exception: measure the
return duct static pressure instead of total external
pressure. Use Page 24 through Page 27.
2-The RPM can be adjusted at the motor pulley. Loosen
Allen screw and turn adjustable pulley clockwise to
increase CFM. Turn counterclockwise to decrease CFM.
See figure 25.
F-Field-Furnished Blower Drives
For field-furnished blower drives, use Page 22 through
Page 27 to determine BHP and RPM required. Reference
Page 30 for supply air blower and high static power exhaust
fan drive kit specifications. Reference tables 5 and 6 to
determine the manufacturer's model number.
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