We want to know about
your drive application experiences. Please e-mail us your comments
and suggestions regarding this site.
This site is constantly changing so check back often. If you are currently
working on a project then tell us about your project
to AC Drive Theory by James M. Shumberg
frequency drives are sometimes called AC drives (the author's preference),
adjustable frequency drives, VFDs, or inverters. VFDs provide us a
reliable means of adjusting or changing the frequency of alternating
current applied to the motor and thereby changing the motor speed.
More About AC Drives
About AC Induction Motors
Most industrial AC induction motors, manufactured
in the US, are designed to operate with a current that alternates
in the direction of flow 60 times per
second (HZ). If this frequency of alternation is changed, the speed of the motor
changes. By controlling the AC frequency with a variable frequency drive, you
control speed. A proper voltage to frequency ratio (V/HZ) must be supplied. For
most industrial motors manufactured in the US this ratio is 460 volts to 60HZ
or 7.6:1. I.E.: to achieve 10% speed, you should supply 10% frequency
(or 6 HZ). To properly apply electric power at 6HZ the output voltage of the
variable frequency drive must be 45.6 volts
(6HZ x 7.6).
More About AC Induction Motors
used to sell AC & DC drives and Electric Motors.
Now we just give advise on how to integrate them & solve problems.
(Because we think that's the fun part.)
Worldwide Travel With 24 Hours Notice **
AC & DC Drive Related WebSites
This list changes so check back often!
Electrical Training Seminars For Plant
& Engineering Personnel Including Hand-On
Variable Frequency Drive Seminars.
More Great Electrical Seminars Including
Hands-On PLC Training.
Bargains on Used and Surplus Electric Equipment
(View "hot list"
of urgently wanted items.
A great site with How-Tos
for mechanics and electricians
Low Prices on AC & DC Drives
Low Prices on PLCs& Touchscreens
Your one-stop destination for anything you can think about