System Protection Technology

The purpose of this videotape is to familiarize the participant with the features of motor operation and the most common types of protective devices that are installed.

After study of this tape and the associated workbook, participants should be able to understand the following overall concepts and apply them to their day-to-day work activities. They will also be able to answer related test questions on these subjects:

• Motor application: voltage levels
• Induction motor characteristics
• Torque curves: speed, slip, stall
• Potential motor hazards
• Starting arrangements
• Current – time curves
• Thermal limits for overload and start-up
• Thermal and time overcurrent protection
• Locked rotor protection
• Phase fault protection
• Ground fault protection
• Differential protection
• Protection against unbalanced conditions
• Undervoltage protection
• Synchronous motor protection