There are a number of applications around the home and
workplace that require the use of a DC electric motors. It operates by inducing
a magnetic field through a series of wire windings that surround a magnetic
rotor. When you need to replace your motor, it is recommended that you find out
the torque of the old one (which is the name given to the force with which the
shaft turns).
Step 1: Determine the power output of the motor. Generally,
it will be in horsepower, but if you are using an American model it will be
expressed in watts. Pull out the documentation that came with your model to
determine the horsepower and revolutions per minute (RPM).
Step 2: If you cannot find the documents that came with your
electric motors, you will need to calculate the horsepower yourself. You will
need to divide the supply voltage by the engine’s resistance, which will give
you its current. Then, multiply the voltage, current and efficiency (this will
be a percentage that outlines the energy lost due to friction and heat) of the
engine and divide by 746.
Step 3: Divide the horsepower by the speed of the motor (in
RPM) and finish by multiplying the answer with a conversion factor of 5,252.
This should provide you with the engine’s torque in foot-pounds.
Once you have established the torque of your particular DC
electric motor, you will be in a much better position to find a brand new one
that will meet the requirements of the application at hand. If you are unsure
about some of the numbers and values asked for in the calculations outlined
above, you can take your motor to a professional who will be able to do this
for you.
