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6-2
·
The compressors require a stable, cool (140
°
F typical at 80
°
F ambient air) supply of injection oil in
order to operate at optimal efficiency. Under these conditions, the oil core allows 80 gpm oil flow with
6.5 psid pressure loss.
·
The lubricating and cooling oil must be kept at a normal operating temperature below 225
°
F in order
to preserve its longevity.
·
The compressed air supply must be delivered into the distribution system at a temperature not
exceeding 15
°
F above the ambient level in order to protect other devices (e.g., filters, dryers, tools,
etc) against damage. At 100 psi of discharge pressure, the air core allows the flow of 2010 acfm with
.7 psid pressure loss.
AIR-COOLED HEAT EXCHANGERS
– An air-cooling module, separate from the compressor package,
is supplied on air-cooled packages. The module is comprised of individual radiator-type coolers for air
and oil services, a radial cooling fan driven by an inverter-duty, TEFC electric motor, a pulse-width
modulated variable frequency drive to energyze the fan motor, and the fabricated steel base and fan
housing assemblies. Refer to Section 2 for details on the location and installation of the air-cooled
module.
Refer to Figure 6-1 for estimates of ventilation requirements. Please note that the compressor package
lists ventilation requirement for the compressor inlet, motors, and electronics; the air-cooled module list
the ventilation for the heat exchangers. When location makes it necessary to duct fresh cooling air in/out
into both the compressor package enclosure and the air-cooled module, these ducts must be sized with a
maximum (total) pressure loss of 0.2
” water gauge to avoid impacting the heat exchanger cooling air
system.
Minimum Cooling Air Flow Requirements
CFM
GD Model
Air-Cooled
Module Ventilation
Compressor Package
Ventilation
225
20600
8311
260
29200
7721
Figure 6-1 – AIR FLOW CHART
All the required [internal] hardware, mechanical and electrical connections have been made at the
Gardner Denver factory, thus the only regular maintenance required is to keep the exterior core fins free
from dirt and other airborne debris per the following procedure:
Air-cooled heat exchanger cores are fabricated from aluminum. Do not use
caustic liquids to cleanse core or permanent damage will take place.
1. Be sure the unit is completely off and that oil reservoir is depressurized.
2. Disconnect, lockout and tagout power supply to the compressor package and to the air-cooled
module.
3. Locate air-cooler module access panels (See Figure 1-6, page 14) and remove.
4. Inspect cooler cores. If blocked with debris, use a moderate (e.g., 100psi) source of compressed
air and/or water while directing nozzle (pointed through core to outside) to dislodge debris and clean.
5. Remove all loose debris and water from cooler box after cleaning process is complete.
6.
Re-install enclosure door panels.