How to Fix Plastic Pelletizing Machine Motor Overload and High Current: A Practical Guide for Ghana Recycling Plants

If you run a plastic recycling factory in Accra, Kumasi, or anywhere in Ghana, your main motor is the heart of the production line. One of the more worrying problems is when the control panel alarms because the main motor current spikes too high, or the safety breaker trips on overload.

Operators in local West African yards often call this “motor overloading,” “high current,” or “breaker tripping.” When the machine trips, the whole line stops. In Ghana, where electricity tariffs are high and the grid voltage is unstable with sudden Dumsor drops, letting the motor run under sustained high-current strain can burn the copper windings — leading to costly repairs and weeks of downtime.

Why Does Your Plastic Pelletizing Machine Suffer from Motor Overload and High Current?

Many supervisors immediately blame the motor itself when a trip happens. In most Ghanaian workshops, though, the overload is usually mechanical or operational rather than a defect in the motor.

The first cause is a cold start, or not enough pre-heating before starting. When the machine has been sitting, plastic left in the barrel from the previous shift hardens into a stiff block. If the motor is started before the heating bands have melted that crust, the screw locks up and the motor draws heavy current trying to turn it until the safety system trips.

The second cause is hard foreign material in the hopper. Local scrap is often collected from the ground or informal dump sites, so it can carry pieces of iron, stones, heavy bolts, or thick aluminum scraps. When these wedge between the screw flights and the barrel wall, they jam the screw and overload the motor.

The third cause is a wrong temperature profile or a material with very high melt viscosity. If the mixing and metering zones are set too low, the flakes do not melt into a smooth liquid, and the motor has to push thick, semi-solid paste through the screen changer mesh, driving the current past safe limits.

Step 1: Enforcing Strict Pre-Heating Disciplines and Manual Testing

Protect the machine from cold-start overloads by changing how each shift starts the line. Turn on all heating zones and let the machine sit at the target temperatures for at least thirty to forty-five minutes after the panel shows they are reached. That extra soak heats the core of the screw and fully liquefies any residual plastic block.

Before pressing the main motor start button, have the operator turn the gearbox coupling shaft by hand a few rotations with a heavy pipe wrench. With the main breaker locked out and gloves on, a shaft that turns smoothly shows the internal plastic is fully melted, so the motor can start without a high-current spike. Locking out the power first is essential — barring a live coupling risks a sudden rotation and a pinch hazard.

Step 2: Cleaning the Barrel and Installing Strong Hopper Magnets

If a sudden mechanical jam spikes the motor current while running, cut the power and stop the feeding system right away, then have a maintenance technician inspect the feed throat and the first few zones of the barrel.

To stop it happening again, install a heavy-duty, high-strength magnetic separator grid inside the feed hopper. It traps iron filings, nails, and metallic debris in the crushed flakes before they reach the barrel, keeping the screw free and protecting the motor from physical jams.

Step 3: Raising Mixing Zone Temperatures and Upgrading Screen Changers

If the motor current climbs slowly over time and stays high during normal production, the cause is internal flow resistance. Check the temperature controllers and gradually raise the mixing zones and die head adapter by 5 to 10°C. More heat lowers the viscosity of the melt, so the screw pushes it more easily.

Also check the hydraulic screen changer — a clogged filter mesh acts like a wall, building up backpressure that overworks the motor. Changing the wire mesh screens regularly keeps the output flowing and brings the motor current back into a safe, energy-efficient range.

Summary: Keep Your Currents Low to Protect Your Motor and Cut Power Bills

By enforcing strict pre-heating, trapping metallic contaminants with hopper magnets, and lowering melt resistance with proper temperature settings, you can keep motor overloads in check. That means fewer unexpected breaker trips, a longer life for the main motor, and lower electricity and repair bills.

If your plant is dealing with repeated overload trips, or you are comparing machines with motor protection and easy screen-change designs for the Ghana market, our technical team would be glad to review your setup.