COOK HMD EN - Manual (Page 10)

10
Troubleshooting
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Is the air volume too
high?
Adjust drive to
reduce rpm as
needed.
Adjust drive &
increase external
pressure. as needed.
To reverse the rotation on three phase units, disconnect and lock-out the
power, then interchange any two power leads.
To reverse the rotation on single phase units, disconnect and lock-out the
power, then rewire the motor per the motor manufacturer’s instructions.
Replace motor.
Compare the supplied voltage, hertz, and phase with the unit and
motor’s nameplate information. Correct as needed.
Is the static pressure
lower than rated?
Is the blower rotating in
the wrong direction? If
the blower is rotating in
the wrong direction, the
unit will move some air,
but will not perform as
designed.
Is the motor voltage
correct?
Is the motor horse
power too low?
Shorted winding on the
motor?
Consult factory.
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Motor overamps
Measure the unit’s air volume
(cfm) and compare it with its
rated air volume. If the measured
air volume is wrong, adjust the
fan’s RPM by changing/adjusting
the drive. The most accurate
way to measure the air volume
is by using a Pitot traverse
method downstream of the
blower. Changing the air volume
can significantly increase the
motor’s amps. If the air volume
is changed, the motor’s amps
must be checked to prevent
overloading the motor. To ensure
accuracy, the dampers are to be
open when measuring the air
volume.
Refer to the control panel parts list when troubleshooting.