50Hz Motors on 60Hz
and 60Hz Motors on 50Hz. You can run a 50Hz motor
on 60Hz, and a 60Hz motor on 50 Hz provided you adjust the voltage
and power ratings to keep the V/Hz constant.
Calculation of ratings for both Aluminium
busbars and Copper busbars.
An introduction to Brushless DC motors.
An introduction to Compound DC motors.
Dual speed Dahlander motors.
Calculations Software Busbar
ratings, Cable ratings, Power Factor Correction calculations, Motor
Starting and acceleration Curves, Enclosure Cooling, Genset sizing
and numerous metric/imperial conversions.
Ventilation Guidelines for
the correct cooling ventilation of switchboards and enclosures.
Savers for Induction Motors Energy
Saving systems for Induction motors Are they
a sham? Do they work?
There seems to be a resurgence in interest in the Nola energy
saving algorithm for induction motors, with a number of manufacturers
beginning to market "new" and "improved" versions
of this technology.
An introductory paper on the sizing
of engines and alternators when used for motor starting supplies.
GSM Alarm relays can be used to provide alarm text messages from eight channel monitoring and single channel control via text messaging.
GSM Control relays can be used to provide basic two channel monitoring and control via text messaging.
Harmonic filters are used to reduce the harmonics generated by the input rectifier of VFDs.
Motor Control A Paper on induction
motor design covering many aspects of motor design and classification.
Motor starting characteristics are explained. Worth a read.
An introductory paper on industrial
IO as applied to PLCs, and other electronic devices. Currently covering
outputs only, Inputs to follow shortly.
VFDs on Irrigation Pumps for minimum EMC Suggested
codes of practice for installing Variable Frequency Drives on irrigation
pumps with minimum EMC problems.
Invertek Drives Now available in New Zealand.
Induction Motor Calculations Formula for basic induction motor calculations.
Motor Cogging and Crawling Induction
motors will not accelerate to full speed if they either cog or crawl.
This page covers the basic theory.
Logic relays Programmable Logic relays are an easy way to create a flexible and low cost control system using minimum components.
Control Forum . Join the Motor
control on line forum to discuss motor control technology and problems
with like minded experts. Post and answer questions on any aspect
of motor control, starters, soft starters, variable speed drives,
protection and design. NB this is independant of the email forum
Topics currently covered:
Control Mailing List Join
the Motor control email forum to discuss motor control technology
and problems with like minded experts. Post and answer questions
on any aspect of motor control, starters, soft starters, variable
speed drives, protection and design.
Click to join ElecMotorControl
Starters A Paper on
traditional Electromechanical starters including Direct On Line,
Primary resistance, Autotransformer and star delta (wye delta) for
induction motors illustrating how to use them and what characteristics
can be expected.
NO BS Guide to VFDs and EDM
NO BS Guide to VFDs and EMC
An introductory paper on PID control.
Horner OCS are industrial PLCs with an integrated graphical HMI panel.
Power factor correction of A.C. Induction motors
is often poorly understood and more poorly specified.
Factor Calculations Power
factor correction Calculations
Factor Controllers Power factor
correction Controllers for bulk displacement power factor correction.
Factor Correction for Domestic installations
Power factor Correction does not save energy within domestic installations.
Pressure transducers are used to measure the pressure/vacuum of liquids and gasses and convert this to an electrical signal which is typically 4-20mA or 0-5V.
Pressure transducers are commonly used in pump control systems in conjunction with a VFD to regulate the pressure, but can also be used in conjunction with appropriate logic to provide under and over pressure protection.
Password Store Program for
saving encrypted passwords and registration data. Includes a free
random password generator.
DC Motors An introductory
paper on series DC Motors which comprise an armature winding in
series with the field windings.
Schrage Motors are variable speed motors.
Shunt DC Motors
An introduction to Shunt DC motors.
Phase Motors Information and
circuits of common single phase induction motor configurations including
capacitor start and run, and induction start motors.
Smart relays, or Logic relays, are essentially a simplified PLC with limited functionality. They are designed to replace a number of standard electromechanical and electronic relays as found in machine automation where the task does not require a full PLC.
Slip Ring Motors
An introductory paper on
slip ring motors and secondary resistance starters, their control
Starters . An introductory
paper on Solid State Soft Starters. - under construction!
An introductory paper on Space Vector Modulation
Techniques for three phase inverters.
Delta Starters Theory and
applications of start delta (wye delta) starters.
High Inertia Loads Guidelines
for selecting starter and motors for starting high inertia loads.
Voltages from VFDs in Dairy Sheds Stray
voltages from incorrectly installed VFDs cause major problems with
the dairy herd being milked.
VFDs and Harmonics An introductory
paper on VFDs and harmonics
Speed Control An introductory
paper on Variable Speed Control. covering mechanical and electrical
Frequency Drives An introductory
paper on Variable Frequency Drives. This page is under construction.
VFDs and Unscreened Output Cables Screened cables are used between the output of a VFD and the motor to reduce conducted emissions and stray voltages.
VFDs and Energy Saving Using VFDs to save energy.
VFDs and EDM Using VFDs and reducing EDM (Electrical Discharge Machining) bearing damage.