We used the vacuum cleaner motor 2200W 220v in one dental device (vacuum former) as you can see here:
So now one of our costumers said when they used this device the power cable is warmed and when the vacuum motor started the dental clinic circuit breaker (25A C type fuses) trip (could be seen here:)
and disconnect the power of the whole system, so I guess it using 10A for steady-state but I don't know how much current this motor get for startup and could this situation be the result of this trips.
Based this site:
Vpeak = IinR, where Vpeak = √2(V)
and
E = CV2/2
So we have 220v :
√2*220/15=20.74 A
I found this vacuum cleaner’s current waveform from here:
, which is similar, so is this the inrush current of this motor?
I need the causes, and if possible I want to know what is the proper way to solve this problem? Is it good to use soft starter?
Update:
These Vacuum cleaner motor we used in our devices are Brushes.
Best Answer
YES 300% of the rated current is common for start surge of a low-efficiency motor. (high-efficiency BLDC motors use 10x to 12x rated current for start surge)
You may have damaged the motor by excessive winding temp rise from lack of airflow with your design of the vacuum former. So a soft start may only extend the start duration and allow the blocked airflow temperature to rise faster.
A blocked vacuum motor uses more than rated current.
However, using a variac or relay controlled autotransformer can reduce the voltage by 50% and thus current but quadruple the startup time.
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