Section 2
DESCRIPTION
9
control pressure regulator valve modulates the inlet
poppet valve.
UNLOAD MODE - EXCESS OF 535 PSIG (36.8
BAR)
As the required air is reduce, the discharge pres-
sure and line pressure rise above the 535 psig (36.8
bar), the Supervisor Controller activates the unload
solenoid valve which in turn pressurizes the blow-
down valve. This opens the blowdown valve, which
allows discharge air to flow back to the compressor
inlet. Since the inlet poppet valve is fully closed, the
air pressure from the sump tank will be relieved
through the blowdown valve, which will reduce the
sump pressure. Some of the outgoing air will flow
directly into the compressor inlet to avoid cavitation
during this time of blowdown. As the sump pres-
sure drops, motor power consumption is also
reduced. The unload pressure regulator is set to
maintain the unload pressure at the designated
value, 170 psig (11.7 bar). At this time, the com-
pressor is in the unload mode.
When the line pressure drops back to the load point
(cut-in pressure) of the pressure transducer, usual-
ly 525 psig (36.1 bar), the compressor will change
state back to the modulating mode as discussed
earlier. This cycle will repeat itself, maintaining the
demand required on the system line supply.
SHUTDOWN MODE
When the compressor is shut down based on a
manual shutdown, a safety shutdown or an auto-
matic shutdown from the Supervisor Controller
touch pad, the unload solenoid valve is energized
allowing air to flow through the check valve and into
the poppet valve keeping the inlet poppet valve
closed. This also opens the blowdown valve to
allow compressed air to vent back above inlet pop-
pet valve through the inlet filter. The control lines
are properly sized and routed to allow the com-
pressed air to relieve to atmosphere rather than
below the inlet poppet valve.
If the compressor Supervisor Controller is in the
automatic mode, the compressor will shut down
after running unloaded for a specific amount of
time. The reverse also holds true, if the system line
pressure requires additional compressed air, the
compressor will start automatically to satisfy this
demand.
Summary of Contents for LS-20T
Page 6: ......
Page 20: ...Section 2 DESCRIPTION 14 Figure 2 4A Control System Diagram Functional Components...
Page 21: ...Section 2 DESCRIPTION 15 Figure 2 4B Control System Diagram START...
Page 22: ...Section 2 DESCRIPTION 16 Figure 2 4C Control System Diagram MODULATION...
Page 23: ...Section 2 DESCRIPTION 17 Figure 2 4D Control System Diagram FULL LOAD...
Page 24: ...Section 2 DESCRIPTION 18 Figure 2 4E Control System Diagram UNLOAD...
Page 26: ...NOTES 20...
Page 30: ...NOTES 24...
Page 34: ...NOTES 28...
Page 42: ...NOTES 36...
Page 46: ...NOTES 40...
Page 49: ...NOTES 43...
Page 50: ...Section 9 ILLUSTRATIONS AND PARTS LIST 44 02250137 909R00 9 3 MOTOR FRAME COMPRESSOR AND PARTS...
Page 52: ...Section 9 ILLUSTRATIONS AND PARTS LIST 46 02250137 907R03 9 4 AIR INLET SYSTEM...
Page 54: ...Section 9 ILLUSTRATIONS AND PARTS LIST 48 02250137 907R03 9 4 AIR INLET SYSTEM...
Page 56: ...Section 9 ILLUSTRATIONS AND PARTS LIST 50 02250138 702R00 9 5 AIR INLET SUB ASSEMBLY...
Page 58: ...Section 9 ILLUSTRATIONS AND PARTS LIST 52 02250137 908R00 9 6 WATER COOLING SYSTEM...
Page 60: ...Section 9 ILLUSTRATIONS AND PARTS LIST 54 02250137 910R01 9 7 AIR PIPING SYTEM...
Page 62: ...Section 9 ILLUSTRATIONS AND PARTS LIST 56 02250137 912R01 9 8 FLUID PIPING SYSTEM...
Page 64: ...Section 9 ILLUSTRATIONS AND PARTS LIST 58 02250139 798R00 9 9 WATER PIPING SYSTEM...
Page 66: ...Section 9 ILLUSTRATIONS AND PARTS LIST 60 02250137 911R01 9 10 DISCHARGE SYSTEM...
Page 68: ...Section 9 ILLUSTRATIONS AND PARTS LIST 62 02250137 911R01 9 10 DISCHARGE SYSTEM...
Page 70: ...Section 9 ILLUSTRATIONS AND PARTS LIST 64 02250137 911R01 9 10 DISCHARGE SYSTEM...
Page 72: ...Section 9 ILLUSTRATIONS AND PARTS LIST 66 02250137 914R02 9 11 CONTROL START SYSTEM...
Page 74: ...Section 9 ILLUSTRATIONS AND PARTS LIST 68 02250137 914R02 9 11 CONTROL START SYSTEM...
Page 76: ...Section 9 ILLUSTRATIONS AND PARTS LIST 70 9 12 CONTROL PANEL 02250138 633R00...
Page 78: ...Section 9 ILLUSTRATIONS AND PARTS LIST 72 9 13 ENCLOSURE 02250138 672R00...
Page 80: ...Section 9 ILLUSTRATIONS AND PARTS LIST 74 9 13 ENCLOSURE 02250138 672R00...
Page 82: ...Section 9 ILLUSTRATIONS AND PARTS LIST 76 9 14 DECAL GROUP...
Page 84: ...Section 9 ILLUSTRATIONS AND PARTS LIST 78 9 14 DECAL GROUP...
Page 86: ...Section 9 ILLUSTRATIONS AND PARTS LIST 80 9 14 DECAL GROUP...
Page 88: ...Section 9 ILLUSTRATIONS AND PARTS LIST 82 9 15 DECAL LOCATION OPEN MODEL...
Page 90: ...Section 9 ILLUSTRATIONS AND PARTS LIST 84 9 16 DECAL LOCATION ENCLOSED MODEL...
Page 92: ...Section 9 ILLUSTRATIONS AND PARTS LIST 86 9 17 DECAL LOCATION CONTROL BOX...
Page 94: ...Section 9 ILLUSTRATIONS AND PARTS LIST 88 9 18 WIRING DIAGRAM LS20T 525 PSIG 02250137 917R01...
Page 95: ...NOTES 89...