Single- and three-phase alternating current (AC) motor speed can be controlled by controlling the frequency of the voltage coming to it. Motor speed has a lot to do with the capacity of refrigeration ...

Utility power plant generators are usually designed for a power factor (PF) of .8 to .9. If demand-side PF is lower than the designed PF, the generator current will rise above the equipment's rated ...

What is a variable frequency drive? Heating, ventilation, and air conditioning systems' air supply used to be constant volume into a space. Now a variable air volume control is being used to provide ...

The most reliable means for changing shaft speed remains a mechanical variable-speed transmission. These drives are used to provide a variable output speed from a constant-speed power source (as in a ...

What can designers do to ensure higher productivity from the variable-speed drives they place in machines? Markus/B&R USA: When possible, designers can stack or mount drives close together to save ...