Close Transition Star Delta Sequence.

HI ALL

i have a little bit confuse of sequence of start delta closed transition. what i understand is closed transition is to prevent the current spiked when the transition between star and delta are not connected. i just new , so i have study the old electrical schematic what i see in old project of my company first of all.

star contacter closed same time with closed transition contacter
then star contacter open and closed transition contacter remain closed
the delta contacter closed with the closed transition contacter.
and run continuously.

is it right?

from azham
Penang,Malaysia

What Is The Best Initial %voltage Setting For Soft Starter

hi all,

i'm new here, i am in referigeration industries which is use compressor as the heart of our system,
so my question is what is the best setting for inital start up % voltage for the screw compressor 250hp and 300hp. my customer ask me to chek the setting back if it can reduce their demand charge. what i know star connection is 58% so is it beter i put 58% , now my current setting is :

line voltage :415V
Ramp time : 10
initial %voltage is :70% default
curr limit level : 300%