A. About one inch.
17. Q. Should the electrode be raised up to one and one-half inches,
what might happen?
A. If the copper electrode was run at a point so near the clutch, the
intense heat of the arc might do damage to the top carbon holder and
clutch.
18. Q. What regulation should be given to the tension spring No. 93 of
the lamp, and why?
A. This tension spring, No. 93, should be regulated when the current is
off the lamp and should be adjusted only tight enough to pull the magnet
yoke up against the top stop lug on the side of lamp column.
19. Q. If this tension spring was tightened too tightly, what might
happen?
A. At usual speed between stations, the movement of the engine would
impart an added resistance against the pull of the solenoid by the
tension spring, which would shorten up the arc and dim down the light.
20. Q. Is there anything else that could cause the light to dim down
when the engine is running fast?
A. Yes; if the spring No. 92-A that hold the heel of the clutch should
be too weak, the heel of the clutch would be forced up by the motion of
the locomotive; this would release the carbon which would fall to the
point of the copper electrode, causing the light to dim down, or, if the
clutch should be used until the sharp edge that grips the carbon should
have become worn smooth or round, the same would occur.
21. Q. If the light burns satisfactorily while the engine is in motion,
but goes out when engine is stopped, where would you find the trouble?
A. This trouble is most always found to be caused by the tension spring
No. 93 being too weak, though if the dash-pot plunger has become
corroded until it sticks in the dash-pot, the light will act the same as
if the tension spring were too weak.