Compu-aire SYSTEM 2100 Installation, Operation And Maintenance Manual page 26

Adjustment of the air flow may be desired based on air balancing requirement. The
air flow must be checked and adjusted for minimum and maximum CFM
requirements. The air flow can be readily adjusted with the minimum and maximum
output voltage limit from the controller. After the unit has been started and the air
flow properly adjusted, check the blower motor current to ensure that the motor is
not overloaded. Any time the blower speed is increased, the blower motor current
should be checked. If a field adjustment is made, the motor should run for at least
one hour at maximum design room temperature to see if motor trips on internal
overload.
D. No air flow & Clogged filter adjustment
The "No Air Flow" light and alarm should be checked prior to the completion of the
installation. Although the control adjusted at the factory, varying local conditions
make it impossible to provide accurate pressure adjustments.
To check the filter pressure switch, let the unit operate on cooling for about 30
minutes. This will allow the evaporator coil surface to become wet. The air pressure
differential switch is provided with adjustable knob. Set the knob to desire pressure
drop for dirty filter and verify the Dirty Filter alarm. With the unit cooling and filters
in place, block off approximately 75% of the air intake. If the sensing device is
correctly adjusted, the "Clogged Filter" alarm should energize; the sensing device
should have just turned on the alarm at the 75% blocked inlet condition. An Air Flow
Sail switch is also provided at the discharge side of the blower and will activate the
No Air Flow malfunction light and alarm.
Similar to the clogged filter switch, adjustment may be necessary for the no air flow
switch(s). The loss of airflow switch is wired in the normally closed position to open
on airflow and the dirty filter switch is wired to the normally open position and set
to close with dirty filter. Adjustment can be made by removing the top cover and
turning the dial to the proper pressure. See Figure 9 below.
Rev. 01
05/27/2016
Page 26 of 42
Compu-Aire