PLUG Power Proliferating in Utility Vehicles
Tips for Making the Best Choice for Utility Truck Applications
Tips for Making the Best Choice for Utility Truck Applications
By Wanda Kenton Smith
People are surrounded by gadgets—iPhones, BlackBerrys, mp3 players, laptops, iPads and more. These devices compete for our attention, our dollar and even for space—in our trucks.
Considering the mix of charger cables and power needs, not to mention the required tools to get jobs done, it’s not surprising that today’s vehicles often have an inverter installed to provide plug power. That elusive power inverter, once considered a luxury reserved for the boss’ pick-up or the workhorse that ran specific tools, has now emerged as the most important must-have, on-board feature. Power inverters are now standard in many applications, including up-fitter packages for work vans, service bodies and mobile office systems. At the original equipment manufacturer (OEM) level, small inverters are now factory-installed options on both Ford and Nissan commercial vehicles. In the future, plug power probably will be available for many new vehicle purchases, but these are limited to charging cell phones—in the meantime, it will be up to you to ensure your inverter is up to the task.
Get Smart About Inverters
Do you have questions about how to analyze the best type of inverter for your needs and application? A professional in commercial inverter applications, Will Tomkinson, commercial and fleet sales manager for Xantrex Technology USA, helps navigate through the process. Tomkinson discusses what is available and what should be considered in a vehicle installation.
Pure sine? Modified sine? Understanding sine quality of an inverter can prove challenging for those who are not current on the technology. Trying to understand waveform quality of ac power is probably not the top priority for a busy contractor or service technician.
“In a nutshell, pure sine—or true sine—inverters have a power quality that most resembles the electricity received from plugs at home or at the office,” Tomkinson said. “Clean and pure, it will run any kind of load—such as at home or on your work bench. If you will be powering a mix of loads and can’t predict with certainty what you might plug into the inverter, try to get a pure sine unit. That way you are covered.”
A modified sine wave inverter, however, represents a step down in waveform quality—but possibly a boost to your budget. Pure sine inverters can cost two to three times more than a modified sine unit, and not everyone needs a more expensive power inverter.
“Most loads will run well from a modified sine inverter, even if less efficiently,” Tomkinson said. “Motors, lights, computers and most phone chargers are not a problem. For laser printers, sensitive electronics, programmable logic controller (PLC) devices, dimmer switches and some cordless tool chargers, however, a modified sine unit might not be as effective; if unsure, first try testing your loads on a modified sine unit in another truck.”
Size Does Matter
For most, the sine wave issue is the biggest question in making an inverter decision; sizing is a close second, which can be just as perplexing.
“Get the best, biggest inverter you are comfortable installing because you never know what you might want to plug into it one day,” Tomkinson said. In addition, he recommends that, if using a modified sine inverter, you might want more power.
“Consider sizing your inverter 30 percent higher than your heaviest planned load. Running an inverter for long periods at or near the peak load could lead to excess heat and lower component life. A modified sine inverter with loads plugged into it may turn more of that battery power into heat, lowering the efficiency of the installation and necessitating a larger inverter,” Tomkinson said. Sizing the inverter for your application is easier if you can review load specifications.
“Any inverter model will have a data sheet that lists the continuous power rating and the surge rating. Do not necessarily trust the part name of the inverter because that ‘hypothetical SUPER5000’ may have a 5000W surge load and a 2500W continuous load. Know that before you buy, and remember that most inverters are rated for continuous use at or near their model names,” Tomkinson said.
The Surge Factor
Surge is another consideration when sizing an inverter. What does that surge rating on the data sheet mean?
“There is no standard rating for surge,” Tomkinson said. “Some inverter manufacturers list surge for 10 minutes, some for 10 seconds and some don’t mention it at all. Look for a surge of at least a few seconds.”
The real benefit of knowing your inverter surge rating has to do with surge loads.
“Motor loads are the most common, sometimes showing a surge rating six times their continuous power requirement. Sodium lamps, microwaves and compressors are also surge loads, where, for a fraction of a second, a huge amount of power is needed to start a motor, form a magnetic field or charge capacitors in electronics—an important consideration if you are using the inverter to power a drill, for example. For motors, look for the ‘locked rotor amps’ if you can find it—that is your surge. Size the surge rating of the inverter to the surge rating of the motor. You might not need a large, expensive, heavy inverter to manage the surge; today’s designs can handle surge in smaller, less expensive packages—but remember to use dc cables sized for the surge, too. For large surge capability in a small package, consider an inverter such as Xantrex’s PROsine series, where overbuilt switching components allow for a smaller transformer; it works well for surge loads and the gross vehicle weight, not to mention lighter on the wallet.”
The Price and Quality Equation
So what else is there to know? Price and quality varies from manufacturer to manufacturer. Some brands are common inverters branded especially for a specific distributor, market or importer.
“Always try to look for an inverter that has the manufacturer’s name. They will have developed it, designed the electronics and will stand behind their products,” Tomkinson said.
Another consideration is regulatory approvals. Federal Communications Commission (FCC), Class B will ensure that your inverter will not interfere with other electronics such as citizen’s band radios and global positioning system (GPS) antennae. Look for an FCC mark on the product packaging and the regulatory mark.
“Look for Canadian Standards Association (CSA); Underwriters’ Laboratories (UL); or extract, transform, load (ETL)—these are all coeval marks. Look especially for UL 458 or equal,” Tomkinson said. “This standard is important for work vehicle safety and quality, and is recommended by the American Trucking Association (ATA) for use in commercial vehicles. Without UL 458 regulatory approval, you could later be without ac power, or, worse, be in trouble with your insurer.”
Common Commercial Options and Features
Each application will have its own requirements, but following are a few common options and features used in typical commercial installations:
- Featured on the Xantrex PROwatt SW line of inverters, the on-board Universal Serial Bus (USB) plug charger is for plugging in charging cords for mobile phones and hand-held devices.
- Remote switches can be used to provide a second on and off location, such as at the dash. Some inverters offer remote panels that also display battery and load information.
- Ignition lockout feature on some inverters enables the inverter only if vehicle ignition switch is in accessory position or turned over. This can prevent unnecessary battery drain and jump-starts.
- Automatic transfer switches are built into some inverters. For others an external switch is used, such as the Xantrex 15A PROwatt transfer switch. This allows your ac loads to be powered from the grid on a shore power connection and automatically transfer to the battery when the connection is lost. This option requires an external socket on the side of your truck to plug in the shore power.
“Inverter power is growing in the commercial truck market, for good reason. There is demand. We’re all about meeting the needs of this market and providing a wealth of proven power options to deliver results for our customers,” Tomkinson said.
For more information, contact Will Tomkinson at firstname.lastname@example.org.
About the author: A degreed journalist, Wanda Kenton Smith is an award-winning writer, national marketing columnist, former two-times consumer magazine editor and currently edits two online news and educational publications.