1 Leading particulars
1.1 General description
LE, LF and LT are air-cooled, single-acting piston
compressors. LE and LT are lubricated compressors; LF are
oil-less compressors which deliver oil-free air. LF15 up to
LF40, LE15 up to LE55 and LE75 50 Hz are single-stage
compressors; LE75 60 Hz, LE110/150, LF55/75 and LT are
LE/LF/LT15 up to -55 and LE/LT75 50 Hz are two-cylinder
compressors, LE/LT75 60 Hz, LF75, LE/LT110-150 are three-
Note: Take care that three-cylinder compressors rotate in the
direction as indicated by the arrow on the fan housing (counter-
clockwise seen from fan cowl side).
LE/LF are built for effective working pressures up to 10 bar.
LT are built for effective working pressures up to 30 bar (LT15
only for 15 and 20 bar).
1.1.1 Compressor variants
The Compressor Block (Fig. 1.1) includes:
Crankcase (4) and cylinders (6)
Air inlet filter (AF) and inlet silencer (3)
Air cooler piping (2) and (5)
Unloader (7, as standard on LE/LF/LT40 up to -75, LE/
LT110 and LE150)
Interstage relief valve (8, for LF55/75, LE75 60Hz, LE110/
150 and LT)
The Power Pack comprises (Figs. 1.2/1.3):
For LE/LF/LT15 and -22: the Compressor Block as
described above, with flanged-on electric motor (M), check
valve (CV-Fig. 1.4) and air pressure switch with on/off
switches (13-Fig. 1.4).
For LE/LF/LT40 up to -75, LT/LF110-150: the
Compressor Block as described above, with flanged-on
electric motor (M) and solenoid valve (Y1-Fig. 1.6).
The Complete Unit comprises:
For LE/LF/LT15 and -22: the Power Pack mounted on a
horizontal (Fig. 1.4) or vertical (Fig. 1.5) air receiver (AR)
with air outlet valve (AV), pressure gauge (Gp), safety valve
(SV), air pressure switch with on/off switches (13) and
condensate drain valve (Dm).
For LE/LF/LT40 up to -75, LE/LT110-150 (Fig. 1.6/1.7):
the Power Pack mounted on an air receiver (AR) with air
outlet valve (AV), pressure gauge (Gp), safety valve (SV)
and condensate drain valve (Dm). An electric cubicle (6)
includes the motor starter. A separate air pressure switch
(13) is provided.
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A silencing canopy (1-Fig. 1.13) is available as an option.
The canopy has a hinged top to allow easy access for
The Unsilenced Pack Unit (Fig. 1.8) is a fully operational
unit mounted on a frame (no air receiver). A silencing hood
can be added as an option
LE, LF and LT Trolley units (Figs. 1.15 and 1.16) are mobile
compressors. They are equipped with either a directly flanged
electric motor (LE/LF/LT ETROL Fig. 1.15) or a petrol engine
(LE/LF/LT PETROL Fig. 1.16). The compressors have two
a connection for compressed air at working pressure
a connection for compressed air at reduced pressure via a
1.2 Air flow
1.2.1 LE/LF15 up to -40, LE55 and LE75 50 Hz
Air drawn through air filter (AF) and inlet silencer (1) into
cylinders (3) is compressed, then discharged through cooler
piping (4) and (6) and check valve (CV) into air receiver (AR).
1.2.2 LE75 60 Hz, LE110/150, LF55/75 and LT
Air drawn through air filter (AF) and inlet silencer (1) into LP
(low-pressure) cylinder(s) (7) is compressed, then discharged
to HP (high-pressure) cylinder (8) via intercooler (10).
The air is further compressed and discharged through cooler
piping (6) and check valve (CV) into air receiver (AR).
1.3 Regulating system
1.3.1 LE/LF/LT15 up to -55 with DOL starter
The regulating system includes:
Check valve (CV)
Air pressure switch (MDR) with pressure release valve
(2) and on/off switches (5).
Air pressure switch (MDR) opens and closes its contacts at
pre-set pressures. During loaded operation, the contacts are
closed: the motor is running.