An auxiliary power unit (APU) is a portable, truck-mounted system that can provide climate control and power for trucks without idling.
All of the following information on APU weight exemption for semi trucks is subject to change. Be prepared to show as much documentation as possible whenever you run into a problem!
APUs and auxiliary power generators (gensets) are not really the same, although the terms are sometimes used interchangeably. Auxiliary power units (APUs) typically include an internal combustion engine, compressor and alternator and are fully integrated into the truck's own HVAC system to provide climate control, battery charging and engine heating. The addition of an inverter/charger allows APUs to work as a source of AC power, as well.
With new laws and regulations Trucking cooling heating systems effecting the idle time for truck drivers and trucking companies alike, staying comfortable in the truck cab is becoming more difficult than ever. By not allowing truckers to idle their trucks, they are expected to sweat it out in the summer heat or just ¡°chill out¡± during the winter months. Another aspect which shows the total disregard for our professional truck drivers, not to mention a safety issue. Yes, this is a safety issue.
Anti-idling laws will also increase the use of auxiliary power units (APU) for larger trucks with sleepers. With states passing anti-idling laws, APUs will be necessary to run the heating and cooling systems, TVs, computers, refrigerators, and other electrical accessories a truck driver plugs in when parked.
In the United States, federal Department of Transportation regulations require 10 hours of rest for every 11 hours of driving. During these times, truck drivers often idle their engines to provide heat, light, and power for various comfort items. Although diesel engines are very efficient when idling, it is still financially and environmentally costly to idle them like this, from a fuel consumption and an engine wear perspective.
The APU is designed to eliminate these long idles. Since the generator engine is a fraction of the main engine's displacement, it uses a fraction of the fuel; some models can run for eight hours on one US gallon (¡Ö 4 liters) of diesel. The generator also powers the main engine's block and fuel system heaters, so the main engine can be started easily right before departure if the APU is allowed to run for a period beforehand. An APU can save up to 20 gallons (Cat 600 - 10 hours downtime @ 2 gallons per hour idling) (¡Ö 76 litres) of fuel a day, and can extend the useful life of the main engine by around 100,000 miles (¡Ö 160,000 kilometers), by reducing non-productive run time for semi trucks.
Some vehicle APUs can also use an external shore power connection for their heating and cooling functions, thus eliminating fuel consumption during rest periods altogether. Many truck stops provide shore power connections in their parking areas.
Many officers are unaware of the apu weight exemption, Federal ruling, so, while a state legislature may have adopted the 400 lb allowance for Auxiliary Power Units, the enforcement officers may not be aware of it if you have overweight trucks.
The following is a list of states and the status of their 400 lb APU weight exemption status for Auxiliary Power Units.
To get the 400 lb. APU weight exemption allowance, you'll need to be able to provide:
* certified weight of the Auxiliary Power Unit in writing (if your APU only weighs 380 lbs, you'll only be allowed 380 lbs)
* certified proof (or be able to demonstrate) that the APU is functional (working)
You'll also want to carry a copy of the Federal regulation with you. You can find it in the Electronic Code of Federal Regulations in Title 23 (Highways), part 658.17 (you'll find it in section n).
Update APU Grant
For a limited time OOIDA (Owner-Operator Independent Drivers Association) is offering a program where you can obtain a reimbursement of up to 40 percent of the cost of buying and installing an APU, OOIDA members can obtain more information or apply for the Association’s grant program by calling 1-800-444-5791. You must be a member of OOIDA. Membership fee is $45 for one year and includes one subscription to Land Line Magazine. To join OOIDA or get more information Click Here.
States that have adopted the 400 lb APU weight exemption allowance (officers at the weigh stations may be unaware):
Alabama, Alaska, Arizona, Arkansas, Colorado, Connecticut, Delaware, Florida, Indiana, Kansas, Louisiana, Maine, Minnesota, Missouri, Nebraska, New Mexico, North Dakota, Oklahoma, Oregon, Pennsylvania, South Carolina, Virginia, Washington, West Virginia and Wisconsin.
These state do not have a law in place. There are enforcement policies in place that allow the extra weight. Arkansas, Idaho, Illinois, Iowa, Louisiana, Maryland, Michigan, Mississippi, Montana, Nevada, New Hampshire, New Jersey, New York, Ohio, South Dakota, Texas, Utah, Vermont and Wyoming.
States that do NOT allow the 400-pound APU weight exemption:
California, Georgia, Hawaii, Kentucky, Massachusetts, North Carolina, Rhode Island, Tennessee.
This list was complied from The Department OF Energy.