Table 7-5.—Troubleshooting chart for alternating-current controllers

Table 7-5.—Troubleshooting chart for alternating-current controllers—Continued Trouble Probable cause Remedy Sluggish Operation (Continued) Sticky moving parts. Wipe off all accumulations of oil and dirt. Bearings do not need lubrication. Misalignment of parts. Check for proper alignment. Realign tc reduce friction and test for free movement by hand. Erratic Operation (Unwanted Openings and Closures and Failure of Overload Protection) Short circuits. Grounds. Sneak currents. Loose connections. Test and repair or replace defective parts. Test and repair or replace defective parts. These are usually caused by intermittent grounds or short circuits in the machines or wiring circuit. Test and replace faulty parts or wiring. Tighten all connections. Eliminate any vibrations or rapid temperature changes that may occur in close proximity to the controller. Overheating of Coils Shorted coil. Replace coil. High ambient temperature or poor Relocate controller, use forced ventilation. ventilation or replace with suitable type controller. High voltage. High current. Check for shorted control resistor. Check power-supply voltage. Apply correct voltage. Check current rating of controller. Make check for high voltage above. If necessary, replace with suitable type controller. Loose connections. Tighten all connections. Check for undue vibrations in vicinity. Excessive collection of dirt and grime. Clean but do not reoil parts. If covers dc not fit tightly, realign and adjust fasteners. High humidity, extremely dirty Use oil-immersed controller or dusttight atmosphere, excessive condensa- enclosures. tion, and rapid temperature changes. Operating on wrong frequency. Replace with coil or proper frequency rating. 7-54