Tools

Cable Sizing Application

Click here to register to use our cable sizing application

What Changed

So that we can focus all our efforts on our new application, we have retired our myElectrical.com cable sizing calculator. We recommend you now use our main cable sizing application over at myCableEngineering.com.

myCableEngineering.com

Cable Sizing Software - select, size and manage your power cables using myCableEngineering. All your cables, for all your projects.
  • LV and MV cables up to 33 kV with current capacity in accordance with BS 7671, ERA 69-30 and IEC 60502.
  • Positive and zero sequence impedance to IEC 60609. Voltage drop in accordance with CENELEC CLC/TR 50480.
  • Project management and team collaboration, with clear easy to read calculations and reports.

Our software is the only cloud-based solution and has been built from the ground up to be fully responsive - meaning you can access your cables from anywhere and on any device, desktop, tablet or smartphone.

Induction Motor Calculator

Calculate the synchronous speed, slip and rated torque for an induction motor


Tip: registered users can save calculations.

Symbols

  • f  -  system frequency (Hz)
  • nr  - rated (or rotor) speed (rpm)
  • ns  - synchronous speed (rpm)
  • P   - number of poles
  • Pr  - motor rated power (kW)
  • S   - motor slip (%)
  • Tr  - rated torque (Nm)

Formulae

Synchronous Speed

n s = 120f P

Rotor Slip

S= n s − n r n s ×100%

Note: for locked rotor nr = 0, therefore S = 1. The slip will decrease as the rotor speed increases.

Rated Torque

T r = 9550− P r n r
Control Theory

Control theory looks at how systems work and are controlled from a mathematical view.  This note gives a brief introduction to some of the concepts – more...

How a Digital Substation Works

Traditionally substations have used circuit breakers, current transformers (CT), voltage transformers (VT) and protection relays all wired together using...

Differential protection, the good old days

This morning I was explaining how differential protection works to a junior engineer. To give him something to read I opened up the NPAG (Network Protection...

Restricted Earth Fault Protection

The windings of many medium and small sized transformers are protected by restricted earth fault (REF) systems. The illustration shows the principal of...

Motor Starting - Introduction

Motor starting and its associated problems are well-known to many people who have worked on large industrial processes. However, these things are, of course...

Random Numbers

Using laser optical pulses the random number generator utilizes the time between arrival of random photos to generate the numbers, ensuring true accuracy...

Laplace Transform

Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods...

Standard Cable & Wire Sizes

IEC 60228 is the International Electrotechnical Commission's international standard on conductors of insulated cables. Among other things, it defines a...

Maxwell's Equations - Gauss's Electric Field Law

Gauss's Electrical law defines the relation between charge ("Positive" & "Negative") and electric field.  The law was initially formulated by Carl Friedrich...

Capacitor Theory

Capacitors are widely used in electrical engineering for functions such as energy storage, power factor correction, voltage compensation and many others...

Footer
(click here to extend)
Copyright (c) 2026 myElectrical