Problem of high starting current in fans
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The fans in our factory are used for coal loading and dust removal in coke ovens. When the oven is reversed, the motor current is very high during the first attempt to start it; sometimes it simply fails to start. After a few cycles of use, the current returns to normal. I’m not sure of the exact reason for this
It is normal for the starting current to be high at first; it takes a few cycles before it becomes normal. Could it be a problem with the packing or the oil temperature? Let’s take a look at the experts’ answers together.
It might be that the clearance fit in some area is not optimal, resulting in high friction; once operation begins and the parts run in together, the friction decreases and the starting current is reduced accordingly
Is it a new machine or an old one? I have a new hydrogen production unit here. Last year, when the equipment was installed and ready for commissioning, it was found that the starting current of the exhaust fan was too high, causing the machine to shut down immediately. Later, with some advice from an experienced mechanic, it was discovered that the direction of the blades was incorrect. In a last-ditch effort, we disassembled the machine and removed its insulation layers; upon inspection, it turned out to be true – what a shock! Later, it took 4 days to swap the blades of the two exhaust fans; although the starting current was high when the machines were turned on, the systems did not shut down. (When a fan or pump is started, the ammeter reading is usually very high, even exceeding the red mark; under normal circumstances, it returns to normal after a short while.) ）
Under normal conditions, the current of the blower does not exceed a certain level, while the smoke extractor often experiences extremely high currents during cold-start due to issues related to the temperature of the medium. Reducing the inlet baffle during startup can lower the starting current.
I suggest checking whether it is possible to close the dampers before starting up; indeed, the fan is not operating under load, which reduces the starting current.
Under normal conditions, the current of the blower does not exceed a certain level, while the smoke extractor often experiences extremely high currents during cold-start due to issues related to the temperature of the medium. Reducing the inlet baffle during startup can lower the starting current.
Lubricants have high viscosity and high resistance at startup. After running, it becomes thinner.