Drum Motor (Motorized Pulley) vs. Mag-Drive – Case Study
World’s Largest Poultry Producer Sees 43% Improvement in Electrical Efficiency
Upon first glance, the drum motor and mag-drive seem alike. However, as the saying goes, it’s not what’s on the outside that counts, and in this case, the inside makes all the difference!
Belt conveyors are largely considered a necessary evil due to the fact that the motor-driven systems can eat up as much as 50% of a facility’s power. As a result, many factories continually seek for ways to improve efficiency and lower their monthly electric bill.
One of such factories happens to be the largest poultry producer in the world, who we’ll refer to as “Company X”. In an effort to reduce overhead expenses, Company X replaced their drum motors with mag-drives.
Before we jump to those results, let’s examine both the difference between the two.
(Want to skip to the results? Scroll to the bottom of the page).
Examining the Drum Motor
The drum rotates around a stationary shaft in a motorized pulley. A drum encloses all the moving parts. The motor is in a sealed oil bath for lubrication and cooling.
Benefits and drawbacks
- A sealed drum encloses all the moving parts and lubrication oil of the motorized pulley. This is much hygienic than the conventional electric motor and gearbox system.
- Drum motors are OSHA compliant. Since moving parts are enclosed, it offers better operator safety.
- The drive system is completely decentralized. It eliminates the elaborate system of gearboxes and belts in the conventional setup. This improves operational efficiency.
- Motorized pulleys use way fewer gears than traditional conveyor systems. Still, gears are present in the motor. Any drive system that uses gears will lose power in transmission. A gearless design is better for efficiency.
- Though lubrication oil is in a sealed drum, the chance of oil leakages is not completely eliminated. This poses a critical safety problem especially when the load transported is food.
- Requires regular maintenance.
- Friction between gears and other moving parts causes wear and tear in drum motors. Frequent maintenance is required to mend it.
- Oil leakages are a concern. Regular inspection to catch oil leakages is mandatory.
- Lubrication oil needs a change in regular intervals to maintain performance and to avoid breakdowns.
- The motorized pulley that needs maintenance has to be taken out of operation. This causes disruption in the plant schedules.
In summary, energy is lost as is passes through each rotating component. While drum motors eliminate external gears, the internal gears still result in a loss of efficiency and unreliability.
With this in mind, Company X decided to replace their drum (gear) motors with One Motion (gearless) direct-drive pulleys.
Examining the Mag-Drive
The mag-drive uses an array of magnets to induce torque and mechanical motion. It uses permanent magnets engineered to create a high pole count. A high pole count generates higher torque and mechanical power over a wide range of speeds. It provides significant advantages over drum motors by eliminating many drawbacks.
One Motion™ Direct Drive Technology Creates Rotary Motion by Applying Electromagnetic Force to Magnets
- The gearless design of mag-drive leads to higher efficiency. It can generate the same torque and power while consuming 43% less energy than drum motors.
- Mag-drive does not require oil for lubrication or cooling.
- Eliminates the need for oil leakage inspections.
- Eliminates downtime for oil changes.
- Superior hygiene and safety making mag-drives an ideal solution for the food processing industry.
- Easy to clean with IP65 / IP69k rating. Mag-drives are safe for washdowns. The use of cut shells adds to the ease of cleaning.
- Minimized downtime due to gearless design and oil-free operation.
- Highly reliable with a manufacturer warranty of 3 years.
Keep Your Conveyor Running
Downtimes in a plant operation have major repercussions. The fault of one machine can stop the entire operations of the plant by creating a bottleneck. This causes delays in production, supply chain disruption, higher maintenance cost, and revenue loss. Downtime is to be avoided at all costs.
Mag-drives ensure reliable operation as it experiences less wear and tear with the gearless design. Oil-free operation eliminates the need for regular inspection. It is also a much more hygienic setup with no chance of oil leakage. Manufacturer confidence with a 3-year warranty is a testament to the reliability of mag-drive.
Case Study Results:
To create a fair and accurate test, the power going into the panel that is responsible for running the motors needs to be measured, both before and after the One Motion™ install.
The input power going into the panel is what will ultimately have an affect on the electric bill. Checking the power from the panel to the motor would have other power factors that could skew the test results.
For this reason, measuring the wires going into the panel is ideal as the input power is isolated from other power factor issues going into the motor.
Measuring the amps in this way creates a clear picture of the actual power being spent to power the conveyor.
The electric current on the pre-installed wires were 1.1, 1.1, and 1.3 amps. That is an average of 1.16 amps.
Once the Powered Pulleys were in place, the current on each wire read 0.6, 0.6, and 0.8 amps, which equates to 0.66667 amps. The resulting difference was a reduction of about 44%!
The equation for determining costs looks like this:
P(W) = I(A) × V(V)
Pre One Motion™ Install –
Drum Motor Results:
1.2 (amps) x 480 (voltage) = 576 Watts
When converted to kilowatts, it would be 0.5760.
That equates to 13.824 kWh in a day (24 hours).
Based off of $0.12 per kWh, the resulting monthly cost would be 49.77 and annual cost 597.20.
Post One Motion™ Install –
0.68 (amps) x 480 (voltage) = 326.4 Watts
Converted to kilowatts, it would be 0.3264
That equates to 7.8336 kWh used in a day (24 hours).
Based off of $0.12 per kWh, the resulting monthly cost would now be 28.20 and annual cost $338.41
That’s an overall energy savings of 43%!
It is also worth pointing out the numbers above are based off of just one motor / mag-drive replacement. As more mag-drives are installed, it will continue to have a major impact on the efficiency of the factory.
Want to know how much your factory could improve on efficiency? We created a spreadsheet calculator so that you can play around with the math yourself. Enjoy!