Sullair 300HH User Manual Download

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300HH, 375, 375H, 375HH, 425 AND 425H USER MANUAL R00

SECTION 2

2.10 ELECTRICAL SYSTEM,

FUNCTIONAL DESCRIPTION

The electrical system consists of the basic electrical

elements required to operate the compressor and

also has a system feature that automatically shuts

down the compressor when a malfunction occurs.

The system’s components include: an engine starter,

battery, alternator/ voltage regulator, and a fuel

solenoid. It also has a compressor discharge

temperature switch that will shut the compressor

down if the compressor temperature exceeds 250° F

(121° C). It has an oil pressure switch that will shut

down the compressor if the engine oil pressure goes

too low. An underspeed sensor shuts down the

compressor if the engine speed falls below 1500 rpm

and a low fuel level switch shuts down the engine

when fuel level is low to prevent running the engine

dry (out of fuel). The engine is also equipped with an

ECM (electronic control module).

2.11 COMPRESSOR SHUTDOWN

& WARNING SYSTEM,

FUNCTIONAL DESCRIPTION

The Shutdown System and Annunciator Module

(SSAM) continuously monitors the status of the

compressor. In the event of a shutdown condition,

the SSAM will shut down the compressor and display

(flashing) the appropriate code on the instrument

panel annunciator light. The display will continue

flashing until the ignition switch is turned OFF. The

shutdown codes are:

• One flash: high compressor discharge temperature
• Two flashes: high engine coolant temperature
• Three flashes: low engine oil pressure
• Four flashes: low engine speed
• Five flashes: low fuel level

The SSAM also provides startup logic for the
compressor. When the ignition switch is in the ON
position, the annunciator light will illuminate for 30
seconds. During this 30 second period, pressing the
ignition switch will engage the engine starter. The low
engine speed switch is inactive during this startup
time interval. By the end of these 30 seconds, the
annunciator light goes out and the engine START
cycle is disabled. At this time the system runs all
safety checks including low fuel level.

The engine is equipped with an electronic speed
control and has a shutdown protection/diagnostic
capability. A variety of sensors and a speed control
module interface with the ECM. These sensors

include the following: oil pressure, coolant
temperature, intake manifold, fuel temperature,
timing cranking; and a remote shutdown switch. The
engine speed control module consists of the module
and a pressure transducer. The pressure transducer
senses the compressor control pressure and as the
control pressure increases, the speed control module
decreases the engine speed by lowering the output
voltage to the ECM.

2.12 AFTERCOOLED AND

FILTERED AIR SYSTEM,

FUNCTIONAL DESCRIPTION

Refer to

Figure 2-3

. The purpose of the aftercooled

system is to operate the air compressor in conditions
when compressed air temperature is required to be
within 20° to 25°F (13° to 17°C) of the ambient
temperature.

A selector valve is provided on all aftercooled
compressors. Choosing the aftercooled air
completely forces the airflow from the receiver tank
to the aftercooler. The ambient air which is drawn
through the aftercooler by the engine fan, cools the
compressed air as it passes through the aftercooler
core. Cooled air enters the moisture separator where
condensation is removed from the cooler air and
discharged.

This condensate does carry some oil

and it should be disposed of properly in
accordance with local regulations.

From the moisture separator the air enters the
(optional) first stage filter. Particles and additional
water are removed from the first stage filter.

The

condensate should be drained and stored in a
suitable container.

From the first stage filter, the air

enters the (optional) second stage filter. This filter
removes smaller particles and any additional water.

The condensate should be drained and stored in
a suitable container.

Upon compressor shutdown,

the filters will drain to clear the condensate from the
system. This will prevent freezing in cold conditions.

NOTE

The aftercooler system should not be
operated when the ambient temperature
is below 32°F (0°C). To operate in the non-
aftercooled mode close the aftercooler
selector valve completely.