Motors are found everywhere in buildings, and engineers are responsible for making sure they are sized correctly and have adequate source energy to make them work. The heart of almost every HVAC, plumbing and fire protection system is the source equipment. The majority of the rotating equipment — the fans and pumps that keep our building systems safe and comfortable — are operated by electrical machines called motors. They are the soul that takes the spark and keeps the lights on. How well we understand the relationships between sizing our equipment and coordinating with electrical engineers will help determine how well our complete engineered systems function.
Rotating equipment is typically run with an induction-type motor that uses stationary (stator) and rotating (rotor) magnets that repel each other and spin a shaft. Remember that experiment you did as a kid where two magnets repel or attract each other? The concept is similar to that. Add some high-powered electricity and see what happens. If you have ever wondered what makes a motor spin at 1,800 versus 3,600 revolutions per minute, it is actually a function of how many magnets are used in the construction of the motor, related to a factor of 60 for the 60 cycles of sinusoidal waveforms that find their way through the electrical conductors every second.