Chuck Yung
EASA Senior Technical Support Specialist
It’s easy to assume that shipping an electric motor is as simple as putting it on a truck, but nothing could be further from the truth. This article will cover shipping tips and reinforce the fact that shipping includes picking up the motor – not just delivering it. There are some things we (or a trucking company) can do wrong that could result in expensive repairs.
First, let’s address perhaps the most easily overlooked step. When a driver is preparing to deliver a motor, look at the incoming photo and compare it to the motor. Are the leads on the correct side? If it came in with a coupling or sheave, is it installed now? What about the junction box, or other auxiliary parts? Is the paint color correct for that particular customer?
A logical time for the driver to make certain the feet are clean is while lifting the motor to load it. Varnish on the feet is not an uncommon thing to overlook, and it’s sure to make the customer unhappy. If the feet have dowel pin holes or threaded jacking bolt holes, make sure they have been cleaned to bare metal. If not, a technician using a cutting torch set to an oxygen-rich flame can quickly remove varnish without overheating or damaging the frame.
On the subject of lifting, large fabricated frame motors should be lifted by all of the factory-specified lifting points. Handling the motor in Figure 1 by only two diagonally opposite corners is a sure way to twist the frame, resulting in soft feet and a non-concentric air gap.
In most cases, it’s best to place large stators in the middle (side-to-side) of the truck bed centered just ahead of the rear axle. Motors with sleeve bearings should always have the shaft blocked (Figure 2). Don’t overlook the importance of blocking the shaft of sleeve bearing motors being picked up for repair. If the motor is placed with the shaft oriented parallel to the driveshaft, blocking the shaft is especially important. A sudden stop with the unblocked shaft towards the rear can result in severe damage to the cast housing where the bearing is shouldered. This is important to convey to the drivers when picking up a motor to be repaired. Motors shipped without a coupling can be blocked, as shown in Figure 2. For motors with a coupling installed, it is often easier to thrust the shaft fully towards the drive end and cut a board to fit tightly between the end bracket and the back of the coupling.
Always ship vertical motors vertically to avoid thrust bearing damage. Rather than stacking cribbing beneath the motor, making it even taller and more precarious, a hole in the bed permits the driver to place the motor flat on the bottom flange for greater security. If the hole is directly above the rear differential, there is a risk of a longer shaft resting on the differential, which is not good for the motor bearings or for the differential. Ideally, the hole should be just forward of the rear axle to avoid that, and a cover plate should be installed to prevent a careless person from stepping into the hole and getting injured.
Many of us have horror stories of a trucker trying to pass under an overpass with a load that is just a bit too tall with grave consequences. In this age, where everyone has a cell phone camera and can instantly post to the Internet, no one wants to see their company logo make the news in such a manner.
Measure the motor height plus that of the truck bed. Add the two values to determine total shipping height and add about six inches (15 centimeters) as a safety factor against bumps, etc., when passing beneath an underpass. In the U.S., there are federal regulations regarding the proper way to secure a load. Visit https://www.truckinginfo.com/157252/cargo-securement-what-you-need-to-know for more information.
For oil-lubricated bearings, drain the oil to prevent wicking or splashing. If a vertical machine is shipped with oil, the splashing oil can start a slow wicking leak due to a combination of capillary action and surface tension. Rather than attaching “fill with oil” tags onto the motor at the service center, get your driver in the habit of taking those along and securely attaching them when the motor is delivered.
One well-known concern when shipping ball- or roller-bearing motors is false brinelling. Vibration due to a rough road or shipping by rail can cause bearing damage. While there is not much we can do to improve the roads, repurposed conveyor belting can be used beneath the motors to lessen the vibration transmitted from the roadway. If there is risk of rain or snow, tarp the load to protect it from the elements. Yes, even a TEFC (IP55) motor.
AVAILABLE IN SPANISH
ANSI/EASA AR100
More information on this topic can be found in ANSI/EASA AR100
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