AC/DC Drives Terminology Crossword
Across
- 5. 1. This device is sometimes used for phase control in the inverter section of a variable frequency drive
- 6. 16. This electronic device is used in the inverter section to rapidly turn on and off voltage pulses to the motor
- 8. 14. A housing for electrical devices and equipment
- 9. 17. The turning force of an electric motor
- 10. 39. With this, there is no net power transferred to the load
- 16. 28. Drives have played a key role in making these air handling systems more efficient.
- 18. 5. Rectified DC uses capacitors to reduce the ______________ in the output signal
- 20. 10. 3rd, 6th, 9th, etc
- 22. 44. A fixed speed that is pre-programmed into the drive
- 23. 8. A rating given to equipment where the load may continue for 3 hours or more
- 28. 51. What?
- 30. 33. Also known as an inductor, this device opposes a change in current
- 31. 20. The peak of an AC sine wave
- 33. 28. When this condition occurs, a drive over or under corrects the speed output to a motor
- 36. 44. How much work can be done in a given amount of time is ____________
- 37. 17. A signal used to monitor motor shaft speed
- 38. 34. A multiple of the base frequency
- 40. 43. A measure of the amount of power that an electric motor can perform
- 43. 25. This form of braking an electric motor utilizes power resistors to help “bleed off” current generated by a spinning motor
- 44. 18. This is usually only a problem with signals of frequencies approx. 450 KHz to 30 MHz
- 46. 4. The second best book ever written
- 47. 27. __________ circuit breakers may not open quickly enough to protect a VFD form over-currents, therefore fuses are the protection of choice
- 48. 9. During this condition, the motor does not rotate smoothly but steps from position to position
- 49. 36. A solid state device that controls the current and voltage signals to the motor. It contains an emmiter, a collector, and a base
- 51. 21. A capacitor is an example of a _________ which can pass certain signals but block others
- 53. 32. This device is used to rapidly turn on and off the DC voltage that is applied to the inverter section of a VFD
- 57. 26. This device opposes a change in voltage
Down
- 1. 38. This device typically converts one form of energy into another
- 2. 6. This device allows current flow in one direction only
- 3. 23. This is the total current draw of a motor when operated at rated capacity
- 4. 24. Across the _______means that the motor is directly connected to the source of power, with no manipulation of the voltage or current signal
- 7. 3. A device that changes AC to DC
- 11. 13. The difference between the synchronous speed and the rotor speed, usually given as a percentage
- 12. 22. KVA is equal to KW
- 13. 12. The earth
- 14. 29. Undesirable electrical disturbances which may be carried by conductors or through the air
- 15. 37. Closed contacts open, and open contacts close
- 16. 7. The term _______ line refers to a condition where the incoming ac supply voltage is above the acceptable range of a VFD
- 17. 56. This controls the current draw of the motor
- 18. 40. Root Mean Square
- 19. 2. This type of display must be backlit to be read in dimly lit areas
- 20. 45. Another name for a SCR
- 21. 49. The ideal waveform
- 24. 53. This type of control uses very fast switching in the inverter section of a VFD
- 25. 11. An adjustable VFD that controls the voltage that is fed to the inverter section
- 26. 12. The control element of a SCR or IGBT
- 27. 41. This is the voltage produced by a motor that opposes the voltage that causes the motor action in the first place
- 29. 55. The association sets the standards for electrical equipment manufacturers
- 32. 30. A ___________ contactor bypass setup could utilize a 4 position switch to enable DOLT
- 34. 47. Another name for a variable frequency drive
- 35. 46. Unlike DC, AC tends to travel along the outer surfaces of conductors. This is known as the _______ effect
- 39. 54. A short to ground
- 41. 19. The ratio of power out to power in
- 42. 35. A(n) _____put follower provides a signal from the VFD that can be used as an input for other controllers or processes
- 43. 48. Once the incoming AC is rectified, the DC travels through the _________ before traveling to the inverter section of a VFD
- 45. 45. A resistance to a change in velocity
- 50. 50. American Wire Gauge
- 52. 7. A unit of measure for frequency
- 54. 52. This type of control does not utilize feedback devices or sensors to monitor motor speed or position
- 55. 42. A ______________ contactor can be used to switch the motor from drive power to line power
- 56. 15. A ______ step VFD is the predecessor of the modern day inverter
- 58. 31. In the U.S., this current changes direction 60 times per second