Hi there! Remember how lab will go if you know what you are doing! I like those reocurring words of yours. Thanks alot 4 all your lifechanging informative and instructive videos.
Thanks for this awesome video. But would like to know this, just as vfd must be used with motors with inverter duty ratings, what specification on a motor would make it compatible with a soft starter?
I am trying to overcome an issue I have found while using a 4.5kw rotary phase converter. The converter draws around 4A in it's normal off load running state but the huge inrush current quite easily trips 20A B class MCBs. I might look at using a D class MCB but I'd prefer to get a handle on the inrush current. I don't think I can simply use a soft starter on the input line as it uses capacitor start to spin up the idler motor. I'm in the UK so 240v is our standard domestic voltage. Any ideas gratefully received. Brilliant lectures and very much appreciated, thank you.
Good question. A rotary phase converter is in effect a single phase motor driving a 3 phase generator. While I do have some experience w single phase motors, I don’t have much experience w single phase reduced voltage starters but I’m certain there’s got to be a soft starter or other technique that’d work.
Hye. We have few Soft starter of 3RW model. Normally it is set at certain min starting voltage and ramped up slowly to reach max voltage. Say we set at min 30% up to 100%, the voltage slowly increase in increment of 30,35,40 etc. Theoretically this is controlled by the firing of the thyristor. However I do not see any specific setting of setting up the firing angle so that it increments as such it reaches 100%. Where does,and how does the drive do this and if I were to change the firing,how can I do it?
I have a 150hp 480 3 phase motor with 12 wires coming out. At first we wanted the wye/delta start method the chose a soft start. Rewiring the motor, i lost the identity of 2 wires due to age and congestion of the wire box. What could happen if the 2 wires are in the wrong bundle? Thanks. Great vid.
I feel your pain. Depends if the wires are intended for the same phase and same polarity or a different phase with a different polarity. Remember the windings occupy different physical spaces on the stator and current direction influences polarity. If you use the wrong phase there will be a hitch in the rotating magnetic field. If you use the wrong polarity a winding will be a N when it's supposed to be a S and vice versa. Check out the motor connections diagram lecture for the consequences: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-gnQlQ1QuFT8.html There is a method of determining unknown windings using an analog voltmeter however I don't have a lecture on this yet. Given you've got 10 of the 12 nailed down you might be able to disconnect the 10 known (label them first!) and use an ohmmeter to determine the remaining 2 unknown connections. (Example: 1 is connected to 4)
Would it be possible to use a soft starter on a single phase three wire motor? Such as a submersible deep well pump with a control box that has a start & run caps to shift the sinus wave to the motor coils.
A generic soft starter as illustrated in this lecture wouldn't care what it's driving (either y or delta configuration). However be aware of soft starters offered by certain manufacturers that may be application specific.
Hey Jim. Congrats!!!! Listen, as a future YT Channel owner, i would like to ask you which program do you use to makes this slides? I do enjoy the way letters looks like
+D. G. Easiest way to dynamically brake a 3 phase AC induction style motor is something called DC injection braking. I'll go over this and other dynamic braking methods in later lectures. Brush up on your "Electromagnetic Interaction" skills!
+D. G. Most definitely although eddy current brakes require a little more hardware than DC injection, typically a disc in which the eddy currents can be generated. Regardless this method is super cool.
