DC vs. AC in the Forklift World

There is a high demand today for vehicles that do not relay solely on fossil fuels. People are far more aware of the growing emission problems, and many regulations are being placed on companies to seek out more environmental friendly practices.

Emissions are not the only issue with transportation, as the cost of fuel has tripled in the last five years. One traditional alternative to fossil fuels is electricity. For many years electric forklifts were limited to transporting smaller loads and being reserved for indoor use only. There have been advancements in the last ten years that has allowed electric (AC and DC) lifts to take the place of many internal combustion powered units. A specific advancement has reviled the fact that we have been using a very inefficient process to power electric industrial equipment.

The very first system to be used to power devices was the DC (direct current) distribution system. Direct current was first developed by Thomas Edison. It was designed to supply a constant amount of voltage to a device. The system was primarily used for the purpose of lighting a light bulb, which was the major purpose of electricity at the time. DC operates very similar to a normal battery, where current is always moving in the same direction, from positive to negative. With this system there was no way of regulating how much power was used, and because of this different copper lines had to be used for devices that required more or less voltage. As you can imagine this was costly to a consumer and a universal source of power was needed.

With an AC (alternating current) distribution system, large amounts of energy can be transported over greater distances. Rather than having a constant level of electricity, AC pulses current from one direction to another. The electricity is passed through a transformer, the same as what's next to your house, which allows energy transfer to be universal. This way any amount of voltage can be transformed in to what is needed for a specific device.

Until the last decade, it was difficult to have variable motor speeds with AC motors. The electronics needed for an AC motor were too bulky and expensive for a forklift. Hauling around a transformer was not practical. Because of many technological advances these AC controllers have become for more compact, less expensive, and energy efficient. When it comes to industrial equipment, factors that are vital to electric vehicles are the maneuverability, comfort, emissions, and operating time in between shifts.

Toyota's AC system forklifts are able to run longer shifts in between charges and cut down on the size of the lift. This may be a small detail, but it has a large impact on the functionality of the lift. Another advantage of having AC powered trucks is that there is virtually no maintenance needed for the motor. DC systems have wire brushes that rotate around magnets to power the motor, which need to be monitored by maintenance and replaced semiannually. With an AC powered system there are virtually no moving parts. No moving parts leads to less heat and less erosion on the internal functions in the forklift.

An AC powered unit can not only save you money on fuel utilization, but on maintenance as well. This is because the AC motor is totally enclosed, which prevents dust and debris from entering the motor. Finally, in most cases, as AC motor produces a fraction of the heat of a DC motor. Companies who have switched from DC powered forklifts to AC power have seen up to a 20% increase in productivity in the right application. DC still remains a strong contender for many applications, but continuing evolution of AC motors has made it a winner for many in the material handling world.

As with all forklift purchases, a correct application survey from a qualified professional can help you find the best lift for your needs. Contact a Shoppa's Mid America sales representative today to get started.