Motors

Need some troubleshooting tips?

• What exactly are the symptoms? Measured conditions-how much (or little), how often, what, when, where-are the details needed.
• How long has this particular trouble been occurring-just started this week, or has been happening on and off for years?
• No matter how seemingly insignificant, what changes in equipment, operations or maintenance practices took place about the same time the troubles began?
• How accurate is the evidence of trouble? If meters were used, what kind were they, and how were they connected?
• What are the ratings-nameplate voltage, current, etc.-of all components involved in the problem (e.g., motors, contactors, fuses, circuit breakers)? Don't assume that the equipment voltage rating matches the circuit.
• What's the circuitry involved? Is a three-phase transformation open delta or open wye rather than a full set of three transformers? If a motor trips off unexpectedly, or won't start, just how is it controlled? Basic one-line and schematic diagrams should be available showing how things are today, not as they were long ago.
• What specific actions have been taken to correct the trouble? What were the results?