Leading round lifting electromagnet

The driving round lifting electromagnet is not just a technical solution. It is the intersection of physics, reliability and daily operation in a scrap yard, foundry or train station. We have seen how one such electromagnet replaced three loaders, reduced crane downtime by 22% and removed 80% of manual operations with cast iron workpieces from the work area. But not all models do the same. Some lose 35% of their strength already at +45 °C. Others can't stand the vibrations from an old overhead crane. Still others break at the first contact with wet scrap. The leading round lifting electromagnet solves these problems systematically.

Why “leading” is not marketing, but an engineering reality

The word "leading" here means three things: stable holding force as temperature changes, resistance to mechanical shock, and predictable load drop as voltage drops. In the LONGI laboratory we tested 17 models from different manufacturers at +60 °C and 95% humidity. Only two retained more than 88% of their nominal strength. One of them is our LJM-RC (Round Core) series. Its magnetic core is made of cold-rolled electrical steel grade 2212 with laser welded joints. This results in 12% less thermal distortion compared to traditional argon welding. The winding is copper wire with double enamel insulation of class H (up to +180 °C), wound using “no air pockets” technology. Result: after 40 minutes of continuous operation, the case temperature does not rise above +72 °C, and the holding force fluctuates within ±2.3%.

Where money is most often lost - and how to avoid it

Clients often ask: “Why did our anchor fall off after six months?” The answer is almost always not the magnet, but the control system. We recorded 63% of failures caused by incorrect selection of the rectifier: too low no-load current, lack of protection against back EMF during shutdown, lack of compensation for voltage drop in the cable. The driving round lifting electromagnet requires a coordinated solution: magnet + rectifier + cable + control system. LONGI comes with an LJM-DCM controller with a “soft shutdown” function - it reduces the current exponentially in 0.8 seconds, preventing shock loads on the suspension and demagnetization of the armature. The option of a built-in winding temperature sensor with output to a SCADA system is also available.

• Operating voltage: DC 220V (allowable range ±15%)
• Maximum holding force: up to 18,500 kg (under ideal conditions - pure steel ≥40 mm thick)
• On/off time: ≤0.3 / ≤0.8 sec
• Protection degree: IP54 (optional - IP65 for open areas)
• Service life: minimum 10 years at 200 cycles per day

How to choose a specific model - without mistakes

There is no one size fits all. Diameter 600mm suitable for scrap up to 120mm. For large-sized castings, take 900–1200 mm. But the key parameter is not the diameter, butspecific force per square centimeter. If your steel is rusty, scaled, or has an uneven surface, the design force will drop by 1.7 to 2.4 times. We recommend: for hand crowbar - power reserve 2.5×; for an automated line - 1.8×; for a foundry with hot billets - 3.0×. LONGI has a free online calculator on its website: enter the type of material, thickness, temperature, operating mode - you get the exact model and recommendations for the cable and rectifier. See the connection diagram on the websiteljmagnet.ru.

Reliability begins not with a magnet, but with diagnostics

We do not sell electromagnets. We help you not to buy them again. Over the past five years, 41% of orders for the Leading Round Lifting Electromagnet were accompanied by free diagnostics of existing equipment: winding resistance was measured, voltage drop in the line was checked, and the crane load graph was analyzed. One customer discovered that his “weak” magnet was performing 38% below nominal due to oxidized contacts in the distribution board - replacing the terminals saved 240 thousand rubles on a new device. Another found out that the vibration did not come from the magnet, but from worn hoist bearings. LONGI provides lifetime technical support. Not an advertisement. It's just a fact: we have 12 engineers with 11 to 27 years of experience in the field of electromagnetic lifting. They speak the same language as your electrician - no slides or presentations.

The driving round lifting electromagnet is not “another component”. This is the point where physics meets economics. Where every percentage loss in retention turns into hours of downtime. Where the right choice today decides the issue of security tomorrow. He works where others are silent: in the rain, in the heat, after a night break, during power surges. Its strength is not in the numbers on the nameplate. The thing is that he doesn't make you think about yourself. It just works.