Sullair LS-32, Operator'S Manual And Parts List

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Section 2
DESCRIPTION
12
before doing so.
Fluid is added to the sump via a capped fluid filler
opening, placed low on the receiver tank to prevent
over-filling of the sump. Two sight glasses enables
the operator to visually monitor the sump fluid level.
2.6 CONTROL SYSTEM, FUNCTIONAL DESCRIP-
TION
Refer to Figures 2-5A , 2-5B , 2-5C , 2-5D and 2-5E .
The purpose of the compressor control system is to
regulate the amount of air being compressed to
match the amount of compressed air being used.
The capacity control system consists of a spiral
valve and an inlet butterfly valve. The functional
description of the control system is described below
in 4 distinct phases of compressor operation. The
following applies to LS-32 Series compressors
ranging from 350 through 400HP. For explanatory
purposes, this description applies to any compres-
sor with an operating range of 60 to 70 psig (4.2 to
4.8 bar). A compressor with any other pressure
range would operate in the same manner except for
the stated pressures.
START MODE - 0 TO 40 PSIG (0 TO 2.8 BAR)
When the compressor (ON) pad is depressed,
the sump pressure will quickly rise from 0 to 40 psig
(0 to 2.8 bar). During this period, both of the pres-
sure regulators and the solenoid valve are closed
and the Sullicon Control and spiral valve are inop-
erative. The spring on the control holds the butterfly
valve fully open while the spiral valve is fully closed
(maximum) position and the compressor pumps at
full rated capacity. The rising compressor air pres-
sure is isolated from the service line in this phase
by the minimum pressure valve set at approximate-
ly 40 psig (2.8 bar).
A standard closed inlet system is provided which
uses air pressure to close the butterfly and opens
the spiral valve to reduce motor torque for starting.
FULL LOAD MODE - 40 TO 60 PSIG (2.8 TO 4.2
BAR)
When the compressed air pressure in the sump
Figure 2-3 Compressor Cooling and Lubrication System