Electric motors power everything from tiny electronics to massive industrial pumps. Yet, they all work on the same basic principles. Though AC motors seem ordinary, there are complex activities going on behind the scenes.

The simplest types of motors are three-phase AC motors. They convert a rotating magnetic field into mechanical rotation. The basic parts of an AC motor are the stator, rotor, bearings, drive shaft, and frame. The supply power is connected to coils of wire that are wrapped around laminated iron cores in the stator; the stationary part of the motor. When the coils of wire receive current, they generate a magnetic field known as poles. Each phase of power has the same number of poles; the poles are spaced evenly around the stator.

Historically, speed control of three-phase induction motors was very difficult. The only way to change the operational speed is to change the frequency of electricity supplied. Today, this task is accomplished by use of a variable frequency drive or VFD. This device is made of three main components: a rectifier, a DC-Link, and an inverter. The rectifier takes the incoming AC voltage and converts it to DC voltage that can be used by the electronics in the VFD. The DC-Link then uses capacitors to help smooth out the DC voltage from the rectifier and feeds it to the inverter.

The inverter then converts the DC voltage back to AC voltage. The inverter also controls the output frequency of the AC power by sending precisely timed pulses of DC power at specific voltages to rebuild the AC sine wave.

With a VFD, not only can the output frequency be controlled, but it can be slowly ramped up. This allows for smoother starting and can be adjusted to keep a motor spinning at a specific frequency. VFDs can produce three-phase power from a single-phase source, or even a DC source, to power highly efficient three-phase motors in locations without a three-phase supply. VFDs can also be incorporated into a PLC system to allow for automatic or remote control.

The combination of a VFD and AC motors offers a wide variety of functions and increased efficiency. Basic understanding of these technologies is essential for any electrician.

When the doors to your home stick, they could be trying to tell you that your home’s  foundation is shifting. If your HVAC system makes funny sounds, it’s begging to be serviced. But what about your electrical system? Outside of an electrical house fire, how does your house try to tell you that it’s in need of some tender love and care by a certified electrician? If you answer yes to any of the following questions, your house is trying to tell you to call an electrician today.

One sign that you should immediately call an electrician is if your circuit breakers are tripping on a regular basis or if you reset the breaker and it re-trips. This is a sign of a bigger electrical system problem that will need the expertise of a certified electrician to diagnosis and remedy.

If your lights flicker often, then there may be a bigger electrical problem with your home. Yes, it is possible that the power grid is being temperamental but it’s far more likely to be something with the wiring in the home. Perhaps even a pesky rodent chewing on wires in the wall leaving you open to a fire hazard.

Much like when you burn food in the oven, a burning smell is definitely a problem. If you cannot pin-point the burning smell to a ruined dinner or lit candle, then you might want to consider contacting an electrician because it could be your outlets or wiring system.

Call us today if you suspect that your home is making a plea for electrical help.