AAON CL-230 - Manual (Page 13)

13
STARTUP cont.
Step 3. Determine blade rotation – on the
concave side of the blade is a blade marking
showing 6WR, 6WL, 7WL, 7WR, or 9WR. The
“L” and “R” denote the rotation of the blade.
Step 4. Replace the pitch insert in the blade root
with an insert of the desired pitch.
Step 5. Replace blades to their original location.
Step 6. Replace all nuts, bolts, and washers on
the fan hub.
Step 7. Replace retaining plates and center boss
to original location.
Step 8. Tighten nuts and bolts to 14 ft-lbs of
torque.
SERVICING AND MAINTENANCE
General:
• Qualified technicians must perform routine
service checks and maintenance. This includes
reading and recording the condensing and
suction pressures and checking for normal sub-
cooling and superheat (see charging information
beginning on page 14).
• Air-cooled and evaporative-cooled condenser
units require different maintenance
schedules/procedures. Unit specific instructions
for both types are included in this manual.
Compressors:
The scroll compressors are fully hermetic and
require no maintenance except keeping the shell
clean.
Refrigerant Filter Driers:
Each refrigerant circuit contains a replaceable
core filter drier. Replacement is recommended
when there is excessive pressure drop across the
assembly or moisture is indicated in a liquid line
sight glass.
The filter driers are provided with pressure taps
and shutoff valves for isolation when changing
the core. For safety purposes a service manifold
must be attached prior to filter maintenance.
Evaporator/Heat Exchangers:
Normally no maintenance or service work will be
required for a matching direct expansion
evaporator with a thermal expansion valve to
regulate refrigerant.