IRCAMTECH/2006/M/D/GM loco/1.0
43
Introduction hand book on GM locomotive February 2006
The compressor is equipped with three cylinders, two
low pressures and one (in the center) high pressure. Air is
sucked through two dry pamic type air filters and compressed
by the two low pressure cylinders. After that the low-pressure
compressed air passed through an intercooler. The intercooler
reduced the compressed air temperatures. A pressure relief
valve is provided on the intercooler for intercooler safety. After
this the compressed air moves on to the high-pressure
cylinder where it is again compressed to main reservoir
pressure. Between the compressor and main reservoir an
aftercooler cooling coil is provided to reduced the air
temperature.
The compressor has its’ own internal oil pump and
pressure lubricating system with an oil filter. The oil level is
checked during running by means of the dipstick mounted on
the side of the compressor crankcase. When adding oil in the
compressor it must be in stop position.
At idle speed and normal operating temperature, the oil
pressure should be between 18-25 psi. A plugged opening is
provided for installation of an oil pressure gauge.
GM locomotive Vs Alco locomotive
1. In GM locomotive the compressor and air is water-cooled
but in Alco loco the compressor and air is cooled by air.
2. Both compressors have its own lubrication system.
3. Both compressors have an intercooler between low-
pressure cylinder and high-pressure cylinder.
4. Both locos have an after cooler cooling coil between the
compressor and reservoir.
5. Both locos have a loading –unloading arrangement.