Problems with Roots blowers
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We have a Roots blower that experiences extremely high current levels; does the current exceed its limit when the frequency goes above 47HZ? I don’t know what the reason is? This Roots blower is belt-driven and features a rotary drum. Another thing: we currently don’t have enough blowers; can two Roots blowers be connected in parallel?
Two Roots blowers can be connected in parallel. The current drawn by Roots blowers can exceed the allowable levels significantly; the reason for this is that the frequency must remain within the permitted range. If it still exceeds this range, then it is necessary to check the installation clearance of the blades, the synchronization of their operation, and whether the relative angles are correct.
What is the motor power of the Roots blower used by the poster? Could there be a problem with the motor having insufficient power? Has the original poster checked the resistance of the check valve at the fan outlet? If the resistance is too high, it can also cause an overcurrent.
When the output frequency of the inverter reaches 47 Hz, the significant increase in inverter current can indeed be attributed to insufficient power of the Roots blower motor.
Other possible causes of overcurrent include: ① Changes in system pressure – a) An increase in pressure due to clogging of the inlet filter or other factors, resulting in negative pressure (an increase in pressure when the outlet pressure remains constant); b) An increase in pressure in the outlet system； The exclusion method is exclusion after inspection. ② Abnormal components cause friction between the stationary and moving parts ； The exclusion method is adjusting the gap. b. Gear damage c. Bearing damage ； The exclusion method is replacement.
This post was last edited by Xiamen Juhong on 2018-1-3 at 08:40. Overclocking of Roots blowers is manifested in the current exceeding the rated current of the frequency converter; if your equipment has been operating in this condition all along, it means the selected model was too small； If it was working well before, but now due to changes in the manufacturing process the air volume has increased and overloading occurs, then the air supply needs to be increased; this can be achieved by adding more machines or replacing them with larger blowers. It’s not a problem to connect blowers in parallel, but since the air volume changes significantly, it is necessary to modify the main pipes; otherwise, if the pipes are too small, it will affect air supply and the load on the equipment.
They can be connected in parallel. Reasons for overcurrent: 1. The hub clearance is too small and does not meet the standards (have the technician adjust it); 2. Excessive load.