Power Management

When Going Green, Consider Contactors

CO2 may be invisible but its impact isn’t. Countries around the world have signed up to cut emissions of it and other greenhouse gases by nearly a third within 10 years. That means more renewable energy and greater energy efficiency, driven in part by government regulations.

OK, that’s the big picture. How does that apply to a plant floor?

Well, some of that depends on where your plant floor is. Countries and regions are handling energy savings in different ways. Some have energy savings targets, with penalties if the targets aren’t hit. So, saving energy is pretty much a necessity.

Even if that’s not the case, though, cutting energy consumption pays off. For instance, every few kilowatt-hours saved translates to a bottom line addition of dollars, euros, or whatever the local currency is.

Now, usually when you look at improving energy efficiency in a plant or a machine, you look at the big items, like the air conditioning or heater or big motors. You then invest in a new process or in drives to reduce and to optimize energy consumption with the goal of getting the same or better productivity.

But here’s a suggestion: don’t stop there. Consider everything, even items that are usually pretty much invisible.

Take contactors. Usually they’re electromechanical, and they’re often overlooked when a machine is being upgraded. New electronics may be installed on a machine in the form of PLC’s, a Human Machine Interface, drives, and sensors to better optimize the process. However, the electromechanical components are frequently left untouched.

A better approach is to consider upgrading the contactors at the same time. It’s best, in either an upgrade or new build, to go with the latest and most energy efficient technology.

For instance, contactors can now have electronic coil control. That way they can be up to 80% more energy efficient as compared to traditional electromechanical AC or DC contactor coils. A single contactor won’t save a lot of energy. But if a facility has machines with thousands of them, those savings would begin to add up.

There are other ways that advanced contactor technology can generate savings as well. They can require less materials and that makes them more eco-friendly in your automation systems. Older contactors need an interface relay to connect to the controller and its inputs/outputs (I/O). Higher rating of new generation of contactors allow a direct I/O connection. Doing that simplifies the system and reduces components.

Getting rid of components and cutting energy consumption has a cascading effect. Transformers and DC power supplies can be smaller. Cabinet fans can be smaller too because less energy consumed means less heat needs to be dissipated.

Also, the new generation of electronic control coils reduce by a factor of 10 the number of standard parts needed when compared to electromechanical contactors. With only four voltage codes, you cover from 24v to 500v in AC or DC voltage. As a result, you can simplify the supply chain. Another outcome is a smaller part inventory, making maintenance easier and reducing costs.

There’s also another way that contactor technology could help the bottom line, and it also has to do with energy. But it’s not energy conservation. Power is sometimes unreliable and can go out. But even if the electricity stays on, a dip in voltage can cause a contactor to open. Say the line input to a machine briefly drops from 240 v to 100 V. If a contactor opens up, the machine stops. Then it has to be restarted, which can take time and wastes energy.

The way to avoid such problems is to adhere to SEMI F47, a certificate for voltage sag immunity. Doing so makes equipment more reliable and more productive. Down times is reduced.

TeSys D Green

TeSys D Green

For an example of one implementation of the latest in contactors, look at our TeSys D Green product. It’s part of our Green Premium line, which is eco-friendly, is RoHS compliant, and is designed and manufactured in a responsible way that complies with the strictest industry standards. You can also download our new eBook and watch this video.

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