Flashcards
Industrial chapterrrrrs 1-3
Cards in this deck (17)
- 1factors considered in Installation of Motors and Control Equipment*Power Source
*Motor Connections
*Motor Type
*Controller Type
*Environment
*Codes and Standards - 2NEMA meaningNational Electrical Manufacturers Association
- 3NEC meaningNational Electrical Code
- 4Types of motor Control Systemsmanual, semiautomatic, and automatic
- 5IEC meaningInternational Electrotechnical Commission
- 6OSHA meaningOccupational Safety and Health Act
- 7they test equipment to determine whether it is safe under different conditions.Underwriters
Laboratories (UL) - 8-generally very simple devices that connect the motor directly to the line -may or may not provide overload protection or low-voltage release -may be accomplished by simply connecting a switch in series with a motorManual controllers
- 9is characterized by the use of push buttons, limit switches, pressure switches, and other sensing devices to control the operation of a magnetic contactor or starterSemiautomatic control
- 10similar to semiautomatic control,however, an operator does not have to initiate certain actions. Once the control conditions have been set, the system will continue to operate on its ownAutomatic control
- 11Functions of Motor Control*Starting
*Stopping
*Jogging or Inching
*Speed Control
*Motor and Circuit Protection
*Surge Protection
*Safety - 12is one of the main purposes of a motor control circuit.Starting
- 13is accomplished by connecting the motor directly to the power line.across the-line starting
- 14the motor to start at a low speed and accelerate to full speed over some period of time.ramping
- 15are methods employed to move a motor with short jabs of power. generally done to move a motor or load into some desired position.Jogging or Inching
- 16the current flow through the MOV (metal oxide varistor) is calledleakage current
- 17—