Change motor direction on Star Delta and Power Factor Capacitor Bank

Dear Sirs,
I have 2 question about electrical problem.
1. We have 30kwx2 which must running at the same time, we control use star delta starter, we tried to start but one of them was wrong direction, we tried one by one by change the phase line it was R S T ( Red, Yellow, Blue) , we exchange the line Yellow to Blue under the main breaker of star delta, we started , during star mode was OK, but when change to delta suddenly tripped of breaker, and delta contactor and start failured. only the main contactor is ok. we check the motor winding by megger are OK. So, what is the correct way to change motor direction by exchange main line incoming?

2. We installed cap bank 6x5Kvar for 23kva of power electricity. the automatic is running ok, but why there is no any power factor improvement although the 6 capacitors has been charged( closed). What should we check to find out the solution. due to low power the Goverment Electricity company provide transformer 20kv-380v some where ( 200mtr) from the main breaker incoming which is connected and distributed to the our small plant . Is it influence to the capacitor bank? due to on the automatic power correction factor showing under compensation.

Thank you very much for the answer and explanation.

Best Regards,

Achmad Muklis
whats app: +6282142224747
asked 1/3/2017
Achmad Muklis2
Achmad Muklis
  • Achmad,

    Difficult questions to answer without being able to do some investigations.

    For you star-delta, the following post may help guide you in some things to look for:

    On the pf corrections, again difficult. Is the pf correction fully commissioning and operating as it should. Is the measurement of pf correct? Have you tried manually switching the capacitors and seeing the effect on the pf?


    - Steven McFadyen 1/5/2017

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