A. Usually too high speed of the armature, although should you connect
the wires up wrong that the current flowing from the dynamo to the lamp
should enter the lamp at the electrode instead of passing through the
carbon first, you would get a green light and fuse the electrode.
27. Q. What arrangements have been made so that you cannot connect the
wires wrong?
A. The positive binding posts, both at the dynamo and the lamp, have
been provided with a much larger hole to receive the wire than has been
made in the negative binding posts, and the ends of the positive wire
should always be bent or doubled back, so that they will just enter the
receptacle in the positive binding posts, but cannot be connected at the
negative binding posts.
28. Q. Should the copper electrode and holder become fused until no
longer serviceable while on the road, what would you do?
A. Would remove the damaged holder from the lamp and substitute either
an iron bolt of sufficient length or a carbon, securing the improvised
electrode in the bracket of lamp same as the electrode holder is held,
only being sure that the end of the bolt or carbon comes up into the
center of the reflector and did not rest on the base of reflector or
lamp.
29. Q. What is the difference between a series wound equipment and a
compound wound equipment, and what advantages are obtained from the use
of the compound equipment.
A. With the series wound equipment, the incandescent cab lights burn
only with the arc lamp, while with the compound machine the incandescent
lamps are independent of the arc and can be used as desired.
30. Q. If you were running along with your light burning steadily and
nicely, then suddenly the light began to flash badly and kept it up,
where would you look for the trouble?
A. Trouble would usually be found at one of the binding posts, where one
of the binding post screws would be found loose.
31. Q. If you were running along with light burning satisfactorily and
suddenly it went out, where would you be likely to find the trouble?
A. You would find that either the carbon had burned out, one of the lead
wires had broken between the dynamo and the lamp, or one of the wires
had gotten loose at the binding post and fallen out.
32. Q. If the light goes out while you are between stations, what course
should an engineer pursue?
A. If the light goes out while you are between stations and an
investigation cannot be made within a few minutes thereafter to
determine the cause, the steam should be shut off from the turbine and
the dynamo stopped until such time when the cause of failure can be
determined.