3 Phase, 9 lead, 6 contactors control motor not running
3 Phase, 9 lead, 6 contactors control motor not running
(OP)
I have a few details 480volt, 3phase, 9 lead motor with all nine leads terminating at 3 contactors.
DOL line starting energizes 2 contactors
they time out/drop out and 2 contactors accelerate motor after motor reaches speed 2 contactors close running motor at speed.
I have been told motor start contactors (2) close but motor does not spin. There is no mechanical load on it/belt is disconnected and motor shaft can be spun by hand.
I will be going to jobsite tomorrow to investigate further.
If anyone has experience with starting method mentioned above I am all ears.
Thanks in advance for any replies.
DOL line starting energizes 2 contactors
they time out/drop out and 2 contactors accelerate motor after motor reaches speed 2 contactors close running motor at speed.
I have been told motor start contactors (2) close but motor does not spin. There is no mechanical load on it/belt is disconnected and motor shaft can be spun by hand.
I will be going to jobsite tomorrow to investigate further.
If anyone has experience with starting method mentioned above I am all ears.
Thanks in advance for any replies.





RE: 3 Phase, 9 lead, 6 contactors control motor not running
Check for continuity between the motor leads.
respectfully
RE: 3 Phase, 9 lead, 6 contactors control motor not running
This is a two-speed motor? Isn't it?
A similar problem was discussed to some depth in http://www
There are links and a list showing speed vs contactor activation.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: 3 Phase, 9 lead, 6 contactors control motor not running
Voltage was o.k but when checking continuity I found 2 motor leads that were terminated at starter panel reversed .
On the bright side I am able to get motor to spin when start button is pushed but only the first 2 contactors close (Starting) the prox that is detecting rpm is bad.Controller needs to see minimum rpm before engaging accelerating contactors. Tomorrow I should have new proximity switch installed and hopefully I will be able to put this job in the memory hole. I did have a diagram of the 6 contactors used for starting/accelerating/running the motor to upload but my computer skills are lacking.
Thanks
RE: 3 Phase, 9 lead, 6 contactors control motor not running
If 7,8 and 9 do not light out, check for continuity between 1,4 and 9. If you have continuity there, check any of them to 7 for example. If this is open, you have a 1 delta start, two delta run with 1-12, 2-10, 3-11 connected internally.
There are not a lot of these out there but they are there. They are basically two voltage motors with the low voltage being 460.
RE: 3 Phase, 9 lead, 6 contactors control motor not running
By the way, you post has contradicting information on the no, of contactors used:
Headline: 6
Post: 3
I could cite a german book for reference, but I'm afraid that won't be helpful.
RE: 3 Phase, 9 lead, 6 contactors control motor not running
C3(contactor)C5 STARTING
C4,C6 ACCELERATING
C1,C5,C6 RUNNING
C3,C5 BRAKING
Motor leads continuity below.
T7-T8-T9.
T1-T4.
T3-T6.
T2-T5.
The motor has a single voltage rating.
480volt
Y YY
30A/93A.
I was not able to install new prox for motor speed today. I still have not seen motor move beyond starting stage.