Siemens motor starter
Posted 08 April 2005 - 02:49 AM
I hope someone can help with this problem.
Posted 14 April 2005 - 01:21 AM
1) Are you sure that you have line power on the "L" side (L1, L2, L3) of the contactor? If not, there is your problem. I'm not trying to be a smart ass, I am just not taking anything for granted here.
2) Are you sure that there is not another safety disconnect somewhere downstream from the starter that is open? I doubt this one because if it were, you would still read voltage on the load side of the contactor when it is on, but let's just cover all of the bases.
3) When you say that "the coil engages" does that mean that you can see the plunger of the contactor being pulled in? If not, what did you mean by that?
4) If it does pull in, turn off power and remove the power conductors. Take your meter and put it in Ohm check or Diode check mode. Manually push the plunger in and check continuity from L to T on each phase. Did you have continuity? If not, for some reason you have a contactor with no contacts! It has happened to me once before. The contactor had come from a distributor's shelf, but someone had used it to rob a set of replacement contacts and returned it to the distributor without telling them.
If you do have continuity, then you were mistaken about one of the other issues above, because if the contacts are closing when the plunger is in, and the plunger pulls in when the start button is pressed, and the line voltage is present when this happens, then you should have voltage on the load side of the contactor when you press the start button.
If not, welcome to "The Twilight Zone!"
Posted 14 April 2005 - 01:23 AM
Posted 07 June 2005 - 03:57 PM
my question is IF i modified this star delta control and let the motor start in Direct on line , is there a risk doing this ????
please advice ?
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