This test is based on the article, Variable Voltage Made Easy, and counts as 3 contact hours (0.3 CEU) of elevator-industry continuing-education credit. Approved by: NAEC for CET, QEI Services and NAESA for QEI (A maximum of 0.2 CEU for online courses per annual renewal period can be applied towards maintenance of qualifications for certified inspectors.) and the states of Florida, Pennsylvania, Arkansas, Kentucky, Virginia and West Virginia.
Learning Objectives - After reading this article, you should have learned about:
- the theory of variable-voltage control applied to elevators using the Ward-Leonard system.
- methods of obtaining control of acceleration, deceleration and leveling.
- how to circumvent residual currents.
- the best way to obtain smooth control of elevator motion.
- the use of damping-field and shunt-field motor control.
- the design and operation of a self-excited generator.
- the methods designed to prevent the hoist motor from pulling through the brake.
- what happens when motor load and slip increase.
- resistance and Star-Delta methods of AC-motor starting.
- troubleshooting noises in the driving motor on a motor-generator set.
- causes of sparking in generators and hoist motors.
- how to check a DC machine or motor-generator set for electrical neutral.
- how to trace various variable-voltage problems to parts of the system.
- how to determine the synchronous speed of a motor.
- determining the causes and finding remedies for rough stops.
Enrollment Procedures:- Include your full name when purchasing the online course.
- Within 2 to 3 business days you will receive an email with the article and instructions for taking the exam.
- Study article.
- Use the provided online link, ID, and Password to login to the Online Testing Center.
- If you scored 80% or above you can immediately print your certificate of completion. If you score below 80% you will have up to two free retakes.