ACM-22CP-IM (05/13)
Page 10
Installation - Fan Speed Control
The Auxiliary Cooling Module (ACM) is equipped with a variable fan speed control that varies the
speed of the fan as a direct function of the system condensing pressure.
When the system is
operating in cooling mode
and the compressor unit turns on, the Auxiliary Cooling Module fan
speed will increase as condensing pressure increases. The fan will reach full speed at the factory-
set condensing pressure.
The system pressure setting and associated condensing temperature for full speed fan has been
factory-set and is shown in Figure 6.
Factory Setting for
Full Speed Fan
Field Adjustment Guide
(per 1/4 Turn)
Condensing
Pressure,
psig
Condensing
Temperature,
ºF
Setting Screw
Rotation
Condensing
Pressure
Change, psig
Condensing
Temperature
Change,
ºF
300
131
1/4 Turn
~12
~3
Figure 6.
R-22
Condensing Pressure and Temperature Information
If it is necessary to adjust the full speed fan pressure setting in the field, the Auxiliary Cooling
Module pressure control may be adjusted by accessing it through the ACM control panel cover.
With the control panel cover removed, the pressure control will appear as it does in the left view of
Figure 7. After removing the sealing plug, the 5/64” Allen key is inserted into the setting screw to
adjust the pressure level and associated condensing temperature for full speed fan operation.
Figure 6 indicates
the change in full speed fan pressure and condensing temperature for each
¼ turn of the setting screw.
CLOCKWISE
rotation of the setting screw I
NCREASES
full speed fan pressure and condensing
temperature.
COUNTER-CLOCKWISE
rotation of the setting screw
REDUCES
full speed fan pressure and
condensing temperature.
