#LIFING MAGNET REPAIR HOW TO#

Magnets should be visually inspected at the beginning of every shift for obvious mechanical damage to welds, wear depth and chain wear. If they truly understand the potential consequences of misusing a magnet, they can be your best ally in extending service life.Ĭonsistent and systematic inspection programs also are key in identifying a magnet that is in the early stages of failure. Operators are the frontline defense in preventing premature magnet failures. To extend the service life of lifting magnets, training programs designed to help crane operators understand the consequences of mishandling or abusing a magnet and the benefits of developing and maintaining a consistent magnet inspection program are recommended. Exceeding duty cycle will have a negative effect on the productivity and life of the magnet. A 75 percent duty cycle magnet can be on approximately seven minutes out of every 10 minutes. A 50 percent duty cycle magnet should be on for five minutes and off for five minutes. Duty cycle is simply time on versus time off and is generally measured in 10-minute intervals. If the pole shoes are not properly designed to allow for maximum flux density, the magnet’s lifting capacity will be negatively affected.ĭuty cycle is critical to understand as it affects the performance of lifting magnets. The magnetic field produced by a magnet coil needs the proper amount of steel section in the center pole shoe and outer pole shoe but also in other areas of the magnet to force the magnetic flux down to the material being lifted. The sizing of pole shoes also affects the magnet’s lift capacity. The denser the material with less air gap, the better the lift capability of the magnet. A greater bottom surface area allows for a larger magnetic field to be generated, thereby creating a superior lift. The number of amps times the number of turns equals the magnetic field. The lift capacity is determined by the ampere/turns in the coil as well as by the surface area of the bottom of the magnet. Operators also need to be aware of the key factors that can affect a magnet’s lift capacity. Although copper-wound magnets offer advantages, they are not the most viable or cost-effective solution for scrap processors. On the other hand, copper-wound magnets are an excellent option for industries that use overhead cranes because they do not have the capacity limits that material handlers do. Today’s machines can be operated so efficiently, a lighter weight aluminum-wound magnet is a great option and also has become an industry standard. With an aluminum-wound magnet, not only can speed be increased when combined with the functionality of today’s cranes, but the lower weight of these magnets will cause less long-term wear and tear on the carrier. Magnet construction can vary by application, but in the scrap processing industry, magnets wound with aluminum strap or aluminum wire are more common.

Whether you have a rubber-tired machine, a tracked machine or even a pedestal crane, weight is an important consideration in magnet selection. Today’s material handlers are designed to be nimble and functional in many different environments. It is important to note that all crane manufacturers have various combinations of boom and stick lengths, which also must be considered when making this calculation. If the combined weight is less than the carrier’s capacity, safe operation is assured.

To determine the carrier’s lift capacity relative to the size and weight of the magnet, use the lift chart to find the carrier’s capacity when the boom and stick are fully extended over the side at ground level, then subtract the weight of the magnet as well as the maximum weight of the material being lifted. This can be done using lift charts provided by the crane manufacturer.

#LIFING MAGNET REPAIR HOW TO#

The first thing for an operator to understand is how to properly and safely size a magnet to optimize the capabilities of the crane or material handler. If a magnet is used per the manufacturer’s specifications and recommended best practices are followed, it can lead to increased production, a lower occurrence of unscheduled downtime, lower overall maintenance costs and greater service life, not only for the magnet but also for related equipment.

It is imperative that operators understand that the lifting magnet’s role is critical to the success and profitability of their businesses. Industrial lifting magnets are critical to material handling in scrap processing facilities, and they sometimes are misunderstood.

Lifing magnet repair