Sullair 185 - 2.9 Electrical System Function

Section 2
DESCRIPTION
15
sump pressure atvarious load or unload conditions.
S
The
hourmeter
indicates the accumulative hours
of compressor operation. This is useful for planning
and logging service operations.
S
The
toggle ignition switch
is used to energize the
electrical system. The starter button is used in con-
junction with the override button. These are used to
start the engine (refertothe compressor’s particular
starting instructions for proper procedure). When
the toggle switch is placed inthe
“
off”position, itwill
Figure 2---6 Instrument Panel Group
shut the compressor down.
S
The
circuit override button
is depressed simulta-
neously with pushing the starter button. This button
allows the electrical circuit to bypass the engine oil
pressure switch when starting. Without this button,
the engine cannot be started, as no oil pressure is
present until the engine is running.
S
The
idle warm---up valve button
is depressed af-
ter sufficient warm---up is achieved for full compres-
sor operation.
S
The
Pressure selector switch
(185H) allows the
selection of the compressor operating pressure
range, 55 to 110 psig (3.8 to 7.6 bar) or 55 to 160
psig (3.8 to 11.0 bar).
S
The
cold weather starting aid
(glow plug button
for
Caterpillar
engines
)
should be used when start-
ing in cold ambients. Press the button and hold for
10---30 seconds (depending upon temperature).
Release prior to attempting to start engine.
2.9 ELECTRICAL SYSTEM, FUNCTIONAL DESCRIP-
TION
R e f e r t o F i g u r e 2 --- 7 o r 2 --- 8 . T h e e l e c t r i c a l s y s t e m i s
comprised of not only the necessary equipment re-
quired tooperate the compressor, but alsoasystem
which shuts down the compressor in the event of a
malfunction. The components of the electrical sys-
tem are an
engine starter,
a
battery,
an
alternator
witha built---in voltage regulator
,a
fuel solenoid
,
a
compressor discharge temperature switch,
which will shut down the compressor should the
compressor temperature exceed 240
_
F (116
_
C),
an
engine water temperature switch
set to shut
down the compressor when water temperature
reaches 225
_
F(107
_
C)for Caterpillar and Cummins
and 239
_
F (115
_
C) for John Deere and an
engine
oil pressure switch
.The
engine oil pressure
switch
is provided to shut down the compressor
when the engine oil pressure becomes insufficient.
Uponstart---up, it isnecessary tooverride orbypass
the engine oil pressure switch by pressing the
over-
ride button
onthe instrument panel until the engine
oil pressure is high enough to close the switch and
complete the circuit to the fuel injection pump sole-
noid valve.