Hi all,

Right now I'm working in an air separation plant in a plant procurement department. My background is chemical engineering but because of my job, I need to know about some electrical things. Here are my questions :

1. I have read some literature about motor starter. I know there are direct online starter, star delta, and soft starter. Direct online give starting current of 6-10 times from rating current. If I use soft starter how many times of starting current from its rating current should I expect?
2. When should I used direct online starter or soft starter?
3. I also read there is some thing called thyristor. What is its function? What is the differences if I use soft starter with thyristor or without it? Is this thyristor only applicable to soft starter or it could be used with direct online starter too? Are there big differences?

Best regards,


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