A. By carefully inspecting the entire equipment before departing on each trip and know that there are no wires with insulation chafed or worn off; that all screws and connections are tight; commutator clean; brushes set in brush holder in the proper manner; carbon in lamp of sufficient length to complete trip; copper electrode cleaned off and oil in both bearings.
39. Q. Why would you not fill the main oil cellar full of oil?
A. If you should fill the main oil cellar full of oil, the oil would run out of the overflow holes on the side and all over the equipment and locomotive and could do the dynamo no good but possibly harm.
40. Q. What is the most vital part of the dynamo?
A. The commutator.
41. Q. What care and attention should be given the commutator?
A. The commutator must be kept clean, free from dirt and grease; the mica must be kept filed down about one-sixty-fourth of an inch below the surface of the bars.
42. Q. How should you clean the commutator, and when?
A. The commutator should be cleaned before starting out on each trip by using a piece of damp waste, rubbing the bars lengthwise, then wipe dry with clean dry piece of waste.
43. Q. What kind of a bearing should the brush have on the commutator?