mechanics corner 9808
Every since Steam Generators, and axle driven Generators was discarded, different systems have been created to Power Passenger cars needs. The 480 volt system was created, since large amounts of current would be required to run air conditioning, heating, and other appliances on cars.
When EMD came out with the f-40phi, they created an auxiliary alternator known in the trade as a Delco. The first engines, 200- 229 have small Delcos. Above this they all have larger Delcos, and are driven through a gearbox similar to a transfer case on a 4 Wheel Drive Vehicle, only on a much larger scale. The reason for this is that the Delco would have to be driven at a slower RPM as to create 480 volts, while the Engine was turning at its maximum RPM for traction motor current, around 600 volts.
Also there is a standby mode where 480 volts is created from the main alternator, comparable to run 5. In standby there is no current to the drive system, so standby can only be used in stations, the advantage is to cut down on noise. Sometimes the cars will go dark as the controls are switched from Standby, switching the power from the main alternator to the Delco, where the Engine operates at full RPM. This is usually experienced just before the train departs.
Large cables connect the Engine to the cars to create constant power through the train.
next time: The General Electric system.