What must be done to a DC generator's field before it can produce current after overhaul?

• A. Flash the field to restore residual magnetism.
• B. Replace the field coil.
• C. Increase the generator speed.
• D. Calibrate the regulator.

Answer: (A)

After an overhaul, the DC generator’s field could have lost its magnetism, and without any magnetism in the poles the generator won’t start to produce voltage. A small amount of magnetism is needed to begin the voltage buildup process, which is provided by briefly energizing the field windings to restore residual magnetism. This flashing of the field gives the poles enough magnetic pull to induce current in the armature as it starts turning, and then the generated voltage increases as the field is properly excited and regulated. Replacing the field coil isn’t necessary unless there’s a fault with the coil itself, simply increasing speed won’t start output without some initial excitation, and calibrating the regulator affects voltage after generation begins, not the initial buildup.