A. When there is short circuit, the engine will labor heavily, run slow with a large volume of steam blowing at the exhaust, there will be no light shown either at the arc or cab lamps, and the carbon point and cab lights will only show a dull red or go entirely out.
35. Q. How will the equipment act when the circuit is broken, either by a broken disconnected wire or a burned-out carbon?
A. With a broken circuit the engine will run noiselessly and fast with very little steam blowing at exhaust and no light will be seen at the arc or on cab lights.
36. Q. If the insulation on the cab wires is worn off until your two wires can come together either directly or through the medium of some metallic substance, what would occur?
A. A short circuit would result that would put out all of your lights.
37. Q. What should be done?
A. Wrap the exposed wire, if you can locate it, with a piece of waste, or if you cannot locate the short circuit, disconnect one of your cab wires from the dynamo. This would give you the benefit of the arc lamp and you can look for the trouble at your leisure.
38. Q. If the light goes out when steam drops back fifteen to twenty pounds, what is the trouble?
A. Either one of the governor valves is stuck shut, short bushing No. 18 in engine cab is worn badly, allowing wheel to drop away from the governor stand so steam passes around wheel to exhaust, or governor springs are too weak.
39. Q. In this case what should be done?