A large vessel is used to mix plastic pellets to eliminate variations from one batch to the next. The pellets are stirred by a large auger in the middle of the hopper. An ultrasonic level meter mounted in the top of the tank measures the height of pellets. This meter works by bouncing sound waves off of the pellets and measuring the time it takes for the sound to return. The weight of the tank is also measured by load cells mounted in the supports under the vessel.

The mixing vessel with motor, gauge, augur, and loadcells

One day, the circuit breaker on the auger motor trips out. You are assigned the task of determining the cause of the problem. The motor controller panel shows that a high amps alarm was set off. The level gauge says that the hopper is only 20% full. The weight gauge is showing 14,500 lbs. on a scale of 4,000 to 15,000 lbs. The hopper weighs 4,500 lbs. when empty.

Which of the following parts are most likely to be malfunctioning?

A. The ultrasonic level meter
B. The weight scale
C. The motor controller
D. The circuit breaker