Subsubsection Pre-charging (PRE)
The pre–magnetization (pre–charging) transformer and switchgear for the pre–magnetizing of the propulsion transformer and the DC filter capacitors is located in this section.
During startup, magnetizing the main transformers and charging the DC filter capacitors will draw a large (> 400 A) current which can affect other parts of the electrical distribution system if not controlled. The pre-charging system reduces the peak currents by limiting the charging rate with resistors and spreading the charging/magnetizing cycle out over about 10 minutes.
Power for pre-charging is supplied by a 440 V circuit from the main switchboard.
