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HARRIS
888-9058-001
WARNING: Disconnect and lockout AC primary power prior to servicing
168
7.7 Maintenance and Troubleshooting
7.7.1 Cooling System
7.7.1.1 Air Filter Replacement
Disposable filter media is used for air filters when the pressure drop exceeds 0.5 inches.
The filter media used is Harris part number 448-0921-000. This part number is for
quantity one and for convenience, they can be ordered by the case of 60 filters. To
purchase locally, the brand is American Air Filter, Frontline Blue, AAF part number is
627-130-500.
Specifications for equivalent media:
•
Initial pressure drop at 300 FPM is 0.09 inches of water
•
Arrestance 80-85 at 300 FPM
Air Filter Pressure Drop Monitoring:
Air filters. must be changed as necessary to allow sufficient air movement
through the cabinet. To establish baseline performance, make the following
measurements:
a.
Connect a sensitive manometer (such as Dwyer model 40-1) to the small hole
in the rear door near the top, see Figure 7-4.
b.
Measure the pressure drop across the filters when new.
c.
Then, block one side of the air input to the cabinet and measure again. Change
the
filters when the pressure drop reaches this value.
d.
Record these values for future reference.
7.7.1.2 Air Switch Adjustment
a.
Turn transmitter OFF and open rear door of the cabinet requiring adjustment.
b.
Remove the tubing connecting the air switch to the port on the divider panel.
c.
Connect a length of tubing from the air switch tube to a tee connector at the
manometer. See Figure 7-5.
d.
Check for +12 volts at J-3 pin 12 on the slave controller, then connect the volt meter
to pin 2.