Reduced starting currents of the induction motor!
One day in my practice I had to solve the problem associated with reducing the starting current of the motor. Was in the presence of a machine through which was powered cooter and he had quite a powerful system of protection and according to this simply could not withstand inrush currents. It was a Sunday afternoon and was required to solve the problem because on Monday as it should, Yes work, so my Director to see that everything revolves not worried and do not growl! Without hesitation, I came to the solution is very simple.. To reduce the inrush currents can be several ways, but I had neither the time nor the means to something somewhere to buy. You can certainly screwed Altivar 61, but this is not a cheap venture. In this case, you smooth start-up and subsequent functional management is guaranteed. You can try to apply Siderovski Altistart, but again who can buy while no money and shop around
I remembered from the course of General Physics, which I had hammered into my head teacher that if you connect a star starting current is always less, but starting torque too. But if it is, I mean enough starting torque, normal start, what to start the motor according to the star schema, and then switch to a triangle.. But it is only in the case that your test engine works well (not heated) when connecting to the triangle too. The solution is simple and the implementation is also simple. In words I think will be clear. We will need a conventional mechanical delay line, such everywhere shaft, we will need it in order transients to localize. Next do a simple functionality to run (the keypad in conjunction with two "decoupled" starters or one break due to the switching voltage. The delay line may be of any well may be in the form of a time relay, which after disconnecting the motor according to the star schema, a couple of seconds (so that momentum is not lost) includes another actuator which already feeds the same engine but in a "triangle". As you can see, so we all worked only need a few parts and an hour of time. As connected in a star or triangle I am most drawn. About how will be computed starting current by the formulas of "Electrical engineering" will find in a textbook. I think the sense of reducing starting current has a powerful induction motor is clear to you, that is what is important!
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