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Recent content by KJLRSA

  1. KJLRSA

    Hawker Siddeley VS1 - Capacitor switching

    Reply from Hawker Siddeley technical " I have checked with our records department and they have confirmed that the records for the VSI equipment was not retained, we’re sorry that we could not be of assistance in this instance but maybe we could assist you in the future. Regards Global...
  2. KJLRSA

    Hawker Siddeley VS1 - Capacitor switching

    Thanks Marmite. I managed to get a hold of someone in the technical division and am waiting for a reply.
  3. KJLRSA

    Hawker Siddeley VS1 - Capacitor switching

    Thank you Marmite for the answer. I have tried to call HS on numerous occasions and have trouble getting through to the correct person in technical. The breakers are Vacuum and are fairly new (installed 2003). The files you attached dont appear to open correctly. Can you please put them up...
  4. KJLRSA

    Hawker Siddeley VS1 - Capacitor switching

    I currently have a spare Hawker Siddley VS1 VCB on my site and would like to switch a 11kV 8000kVAr capacitor bank. Does anyone have any experience with these breakers and whether they are rated for capacitor switching? If possible does someone have a brochure and manual for the breakers. My...
  5. KJLRSA

    Motor PF & Resultant Capacitive Equivalents

    Correct me if I am wrong, but when we design individual motor compensation, you cannot just look at the PF of the motor. We look at the no load(Magnetising) current and size the capacitors to about 85% of this value. If you start just adding caps to the motors, you risk self-synchronization and...
  6. KJLRSA

    Capacitor installation on distribution line

    kVAr out = kVARrated/((kv1/kv2)^2) = 3600/((13.2/4.16)^2) = 357kVAR
  7. KJLRSA

    Capacitor tripping EL

    We have a customer who has just installed a 1100kVAR 6.6kV switched capacitor bank on his system. There are 2 incomers. The one incomers has 2 x banks operating correctly but when the new bank switches in during high loading conditions it trips the earth leakage in the substation 220V DB. It is...
  8. KJLRSA

    Reducing Cpacity of De-tuned PFC Bank

    Magoo2, bypassing the reactor will result in you not knowing where the tuning point will be. With all the unknowns, it is not advisable until a the system is checked with an accurate model.
  9. KJLRSA

    Transformer energization harmonics

    Thanks All... rcwilson, I didn't think that there would be a problem with breaker opening but you are correct, the cap will discharge through the windings. jghrist, thanks your graph is going to help me develop a Etap model to fully test the system before we advise the client. I have a...
  10. KJLRSA

    Reducing Cpacity of De-tuned PFC Bank

    The reactor is specifically designed with a certain kVAR to tune at a point away from any harmonics (De-tune). If you change the kVAr without changing the reactor you might end up tuning on one of the significant harmonics and amplifying it.
  11. KJLRSA

    Transformer energization harmonics

    Hi The capacitor bank is on the primary of the transformer. Have being trying to model with Etap and LT spice but done have enough info regarding the inrush harmonics to transformers
  12. KJLRSA

    Transformer energization harmonics

    I have a customer asking us to directly connect a 11kV 5MVAR capacitor bank with filter reactor tuned to 4.8pu to a 20MVA transformer breaker. The transformer is feeding a submerged arc furnace. The capacitor bank will therefore energize at the same time as the transformer. They don't want to...
  13. KJLRSA

    circuit breaker and capacitor discharge

    Is an active system such as a SVC not better suited to the voltage control problem. Some people I have worked with have suggested resistively grounding the capacitors to discharge quicker. This is practical in LV applications but due to cost of switching devices we found that in MV...
  14. KJLRSA

    Siemens S7-200 analog problems

    Thanks All I was on site yesterday trying all suggestions. It turns out the temp supply we were using was a ungrounded UPS supply. We connected to a VT supply and the problem was sorted. There appeared to be common mode voltage fluctuations due to differing voltage sources. For once an easy...
  15. KJLRSA

    Siemens S7-200 analog problems

    Hi All I currentely have a CPU226 with a EM231 (6ES72310HC220XA0). We are using channel A and B for a 4-20mA Var transducer input. We have a HMI connected to the CPU and this is displaying the scaled VAR value. We are having an issue when the 4-20mA signal is sent to the card, we are having...

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