Double Roller Press Granulator: Current serves as a direct indicator of the compaction load. During normal operation, the main motor current typically remains stable at 70%–85% of its rated value. A sudden spike in current usually signals increased resistance in the compaction zone—potentially caused by an excessive feed rate, high moisture content in the material (leading to roller sticking), or the presence of foreign objects within the roller gap. Conversely, consistently low current may indicate insufficient feeding or the rollers spinning idly; if left unaddressed, this can accelerate wear on the roller shells. The stable operation of a roller press granulator depends on balancing the feed rate with the machine's compaction capacity, and the ammeter provides the most intuitive indication of this balance.

Roller Press Granulation Line: Current fluctuations reveal feeding issues. In a roller press granulation line, fluctuations in the material level within the buffer hopper are directly reflected in the granulator’s motor current. If the material level is too high, the screw feeder pushes an excessive amount of material into the compaction zone, causing the current to surge; if the level is too low, the compaction zone is "starved," causing the current to drop. Operators who rely solely on material level indicators often react more slowly than the changes in current would suggest. Linking the current signal to a variable-frequency feeder—automatically reducing the feed speed when the current reaches 90% of its rated value—is an effective method to prevent overloading and blockages.

BB Fertilizer Mixer: Abnormal current reflects the mixing state. A BB fertilizer mixer processes granular materials; under normal mixing conditions, the motor current remains steady. A sudden spike in the mixer’s electrical current may indicate an overload—occurring when the load factor exceeds 70%, leading to increased resistance as materials are agitated within the chamber—or it could mean that the discharge gate has not closed completely, causing materials to be repeatedly compressed inside the chamber. In a BB (bulk blend) fertilizer production line, the mixer’s current is synchronized with the batching scales and the packaging machine; therefore, an abnormal current reading often signals an issue in the coordination between upstream and downstream processes.