Fluid Filter; Purge Oil Return Line; Cooling System; General Description Of The Cooling System - Sullair ShopTek ST18 Operation & Maintenance Manual

2: Description
Additional information
• For the viscosity required for the compressor
fluid to act as a sealant, see Section 3.2: Lubri-
cant specifications on page 17.
2.4.3

Fluid filter

The fluid filter collects any impurities in the compressor
fluid and ensures that only clean fluid enters the air end
compression chamber and internal lubrication feeds. If
these impurities in the fluid were not removed, they would
cause wear on the rotor and gear surfaces and bearings
and shorten the life of compressor.
2.4.3.1 Fluid filter element
Because the fluid filter element collects impurities on its
surface, the fluid filter element must be replaced regularly
to ensure good fluid circulation for proper lubrication and
cooling.
Additional information
• For the recommended fluid filter maintenance
schedule, see Section 6.3: Recommended
maintenance schedule on page 28.
• For instructions on how to change the fluid filter
element, see Section 6.4.3: Fluid filter mainte-
nance on page 30.
2.4.4

Purge oil return line

The purge oil return line located on the cover of the fluid/
air separator passes the compressor fluid collected by
the fluid/air separator element through the purge line fil-
ter, then returns the clean fluid to the compressor air end.
A small orifice in the purge oil return line limits return air
flow, minimizing the loss of compressed air. A sight glass
located in the purge line allows an operator to observe
the amount of fluid returning from the separator element.

2.5 Cooling system

The cooling system maintains a proper operating temper-
ature for the compressor.
2.5.1 General description of the cooling
system
Suction created by an axial flow cooling fan pulls cooling
air through louvers on both sides of the compressor. This
cooling air draws heat from the aftercooler before flowing
out of the machine.
14
ST18 & ST22 (U.S.A. & Mexico) Operation & Maintenance Manual
88291013-137 R05
Subject to EAR, ECCN EAR99 and related export control restrictions.
2.5.2

Ambient temperature

Sullair ShopTek™ compressors are designed to operate
in ambient temperatures between 4°C and 40°C (40°F
and 104°F), measured at the cooling air inlet. If you need
to operate the compressor in a temperature outside this
range, contact your Sullair representative.
2.5.2.1 High ambient temperature and
overheating
If the ambient temperature is above 40°C (104°F), the air
drawn into the compressor may be too hot to adequately
cool the compressor fluid or the electric motor when the
compressor is operating at full load. If the compressor
load is less than 100%, operating the compressor in
higher ambient temperatures may be possible.
Regardless of the ambient temperature, the maximum
recommended operating temperature is 108°C (226°F).
Continuously exceeding the maximum operating
temperature will damage the compressor.
In the event of a high operating temperature
shutdown fault, do not attempt to restart the
compressor without first finding and correcting
the underlying cause. Contact your Sullair repre-
sentative for assistance.

2.6 Fluid/air separation system

The fluid/air separator system removes the fluid from the
compressed air stream. The primary components of the
fluid/air separation system are the fluid/air separator tank
and fluid/air separator element.
2.6.1 General description of the fluid/air
separation system
The compressed air/fluid mixture from the air end flows
into the fluid/air separator and strikes the wall of the sep-
arator tank, causing large drops of fluid to form because
of the lower air speed. Most of these fluid drops attach to
the wall of the tank, and gravity causes the drops to col-
lect at the bottom of the tank. The thermal valve then
routes this collected fluid back to the air end through the
aftercooler (if necessary) and the filter.
CAUTION
CAUTION