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.

A recent report from the National Association of Home Builders (NAHB) has found that builder confidence is up industrywide when it comes to home construction this month. In the group's Housing Market Index - a monthly study compiled in conjunction with financial giant Wells Fargo - the composite ticked upward three basis points from April to May, now sitting at a healthy 44 for the period.

"Builders are noting an increased sense of urgency among potential buyers as a result of thinning inventories of homes for sale, continuing affordable mortgage rates and strengthening local economies. This is definitely an encouraging sign even amidst rising challenges with regard to the cost and availability of building materials, lots and labor," NAHB Chairman Rick Judson, a home builder from Charlotte, N.C., stated in the group's press release.

For months, activity has been ramping up in the housing industry, with buyers flooding the market faster than home builders could keep pace. With the busy summer real estate season just about to begin, the supply of new residences is anticipated to tighten even more if buyers can't keep up.

You can help keep your electrical system in safe working order by being mindful and following some simple precautions. Check out Direct Energy's infographic for some basic electrical home maintenance tips that will keep you a step ahead. It's also a good idea to call in a professional electrician once a year to make a check of your system.

We're always here to help at local Mister Sparky.® Give us a call for advice or to schedule a check on your home's electrical system.

So when customers ask us how many ‘Watts” do I need to replace an existing light source, we always convert them to lumens.

•  Pay special attention to the lumens per watt of a fixture. IT DOES MATTER. A LED product at 135 lumens/watt will consume far less energy than a LED product producing 97 lumens/watt. Not all LED solutions are the same. (remember, always buy on the lumens you need, never on the watts you think you need.).

•  To calculate lumens per watt, take the total number of lumens a product produces and divide it by the watts it consumes.

For indoor fixtures, figure on:

utility company. You can check if a product is DLC Qualified on the DesignLights Consortium website. DLC has rebates for Commercial LED Lighting and Industrial LED Lighting

•  Rebates with DLC Premium should be higher than rebates with DLC Standard. Your utility company is typically who provides the rebates and sets the rebate amounts.  Check their website.

•  All UL Listed or ETL Listed.

•  Replacing the light parts of an existing fixture with the a Retrofit unit will not void the UL/ETL Listing of the fixture. However, the exception to this rule are explosion proof rated fixtures (ie. Class I Div 2). Never retrofit a certified explosion proof fixture. UL1598C does not cover these types of retrofits.

•  ETL Listing is the same as UL Listing. They perform the same test, and the certification is the same. The only difference is that the company who performs the test.

Imagine a future free from electricity bills. A home where you can maintain or improve your current levels of comfort, but one that is so efficient that it costs little to nothing to power its electrical work. Someday soon, this vision could become a reality, with a combination of renewable power generation and hyper-efficient technologies allowing Americans to enjoy elevated standards of living without placing a burden on their pocketbooks or the environment. Read on to learn more about the ultimate in energy-efficient homes.

Testing the Effectiveness of New Technology

One hotbed for innovation in efficient home construction is in the Pacific Northwest. A pilot program comprised of builders and utility companies is studying new homes built in Idaho, Montana, Oregon and Washington to discover how new technologies are functioning and which ones are most effective. The program is looking at homes that are at least 30 percent more efficient than required by local code and monitoring them for a year after they are built to ensure that their performance is living up to their promise.

Among the energy-saving features that are included in the new houses:

Filling in the Other Side of the Equation

Naturally, any modern home should also include features like LED lighting technology in lieu of incandescent bulbs and efficient Energy Star-rated appliances to keep the costs for your electrical work low. Add smart technology to the mix, which can automatically find extra savings, and you are looking at a historically low electrical bill.

Of course, it's extraordinarily rare to find an American household that gets by without electricity at all, so no matter how efficient you are, you'll still have some level of energy consumption to power your electrical work. That's where the other side of the equation comes in: personal, renewable power generation. Once you install solar panels or a wind turbine on your property, you can make your own power. Pair that with a good electricity storage option and you're well on your way to being free from electrical bills forever.

Conservation in Your Circuits and Wires

The nation hasn't realized its efficiency dreams yet, but we are well on our way. If you need electrical work in a new or existing home, call up a qualified residential electrician today.