Installation and operating instructions Read all instructions carefully before starting the compressor. General Information L  Series  compressors  are  belt  driven  two-cylinder,  air-cooled,  single-acting  piston  machines.    LE  or  LEN  designates single-stage  and  LT  two-stage.    The  LEN  are  oil-less  compressors  delivering  oil-free  air.    The  LE's  are  available  2 through 10 HP, the LT's 2 through 20 HP, the LEN's 5 and 712 HP. The LE and LEN compressors are built for effective working pressures of up to 120 psig, LT for pressures of 175 psig. The compressors are available as base mounted units, which consist of the compressor block, base, drive, and motor, and as complete tank-mounted units. Operation - LE Series and LEN Series Air is drawn through the intake filter, intake manifold and suction disks into the cylinders.  The    air    is    compressed,    then discharged  through  the  delivery  disks  to  the  temperature  reducer,  where  the  heat  of  the  compressed  air  is  partly removed.  From the temperature reducer the compressed air is discharged through the check valve into the tank. Operation - LT Series Air  is  drawn  through  the  intake  filter,  intake  manifold  and  into  the  low-pressure  cylinder,  where  it  is  compressed,  then discharged through the delivery valve to the intercooler, where the heat from the first stage of compression is removed. The  air  then  enters  the  high-pressure  cylinder  through  the  pulsation  damper  and  the  suction  disk,  where  it  is  further compressed.  It is then discharged through the delivery disk to the cooling caps of the HP cylinder head and from there to the HP temperature reducer.  It is then discharged through the check valve into the tank. Lubrication (not for LEN) L Series compressors shipped from the factory contain a PAO synthetic lubricant.  The compressors may be identified by a yellow label at the oil filler plug stating the unit contains "Airlet Fluid". If not available, a good-quality motor oil (not multigrade) or diester synthetic lubricant may be used.  See chart. Use only reputable brands of oil and once a brand has been adopted, keep to it.  Never mix oils of different brands or types.  The crankcase oil capacity of the various units is given in section 7. NOTES: The crankcase is connected to the air intake silencer or suction line through a breather valve.  Faulty operation of this valve or clogging of the metered hole will result in too high a crankcase pressure and promote oil consumption. Always securely tighten the oil filler plug after adding oil. LUBRICATION LE/LT COMPRESSORS LUBRICANT AMBIENT TEMPERATURE VISCOSITY GRADE A.P.I. SERVICE COMPRESSOR CHANGE INTERVAL (2) BRAND MOTOR OIL MINERAL 5°  F to 104° F SAE 10W20 SE/CC/ SE/CD LE/LT 2000 HRS (1) MOTOR OIL SYNTHETIC 5°  F to 104° F SAE 10W30 SF/CD LE/LT 2000 HRS (1) Mobil 1 PAO SYNTHESIZED HYDROCARBONS (POLYALPHAOLEFINE -15°  F to 122° F ISO VG 32 SF/CD LE/LT 2000 HRS (1) Nuodex Anderol 3032 Chevron/Gulf GSL-838A(3) DIESRER -15°  F to 122° F ISO VG 32 SF/CD LE/LT ANNUALLY Nuodex Anderol 495 Mobil Rarus 824 SYNTHETIC -15°  F to 104° F SAE 10W40 SF/CD LE/LT ANNUALLY Nuodex Anderol 800 NOTES: (1) Change interval shown (hours) or annually, whichever occurs first. (2) Atlas Copco does not recommend the use of specific lubricants.  These lubricants appear to meet the specifications.  There may be other quality lubricants which also meet these specifications. (3) If the local supplier of either Chevron or Gulf industrial lubricants cannot supply this fluid, contact the Synthetic Fluids Business Group.  Chevron Chemical Company at Houston, Texas.  Telephone 800- 231-0172.