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Recent content by squeeky

  1. squeeky

    Better Options than Meggering for 4160V Alternator?

    Becareful with the Hipot as it does stress the insulation and you could pop it. I would start low and work up. I am not in the office at the moment but If you have the PI test results and they look good are you comparing with previous results? 500v DC is like 1000v AC as the electrical stresses...
  2. squeeky

    motor softstarter troubleshoot

    It looks like you have a brake in your circuit. Look at break wear. The inertia, may have the motor still turning when you change direction. This will cause high current.
  3. squeeky

    Unidirectional or Bidirectional

    This is a uni-driectional fan. The blades slope. Think of this as a centrifugal pump. From your phot this should turn clockwise.
  4. squeeky

    Running 3-phase motor on single phase

    I have never tried the Steinmetz connection. I have used the capacitor method but the motor did run hot as it is very inefficient. Here are my notes. Welcome to the forum. Lots to learn and nice people. I hope to emulate you. Well done. My dad was born in 1919. Survived WW2 and then was...
  5. squeeky

    Contator coil failure

    Sometimes dirt on the pole faces or even rust can cause a chatter but my money is on the fact that it did not fully close. If the former, wipe a small amount of oil across the face with your finger. Also the use of VPCI in the panel would assist to prevent this. There is a tendancy to move to...
  6. squeeky

    switch off motor with limit switches

    If your access to the circuit is via the power side, you can still run your relay into the power circuit and limit the power relay via your limit switches. You will have to watch the overshoot from the inertia. The activation section may have to be extended to cover the overshoot or it may start...
  7. squeeky

    UPS protection and distribution.

    Hi Sibeen, My English! The inverter has a 400v, 4 wire primary, from a star transformer, 11 000v to 400v, 2 000kVA, DYn11. The primary of the inverter / UPS is indipendant to the output. The inverter runs all the time. It converts the 400v AC to DC on a bus which charges teh Battery backup...
  8. squeeky

    Anybody help with strange voltages and an alternator problem

    What changed? Has someone laid a new cable or wires near the metering wires? Have you lost the earth screen on the power cables with a bad gland connection. Looking at the imbalnace it is 0.1% That is very small. 40v on a 400v system. Have you lost your reference earth and thus your neutral...
  9. squeeky

    UPS protection and distribution.

    Dear Sibeen, Sorry I travel ad have been away in Swaziland where this problem exists. The transformer feeds into the UPS. Yes the star point is earthed. The UPS runs a system where it charges a DC bus which is then chopped up into three phase AC so the primary and secondary sides of the UPS are...
  10. squeeky

    UPS protection and distribution.

    At an installation there is a 400v, 50Hz, 3 ph,4wire, DB with a Fault Level of 35kA. It is fed from a 1MVA, 11kV to 400v, DYn11 trf. This DB feeds a 40kVA, three phase, UPS device. In the Main DB the breaker feeding the UPS is a 125A thermal magnetic MCB set at the correct levels. No earth...
  11. squeeky

    Delta Star Connection Problem

    Dear MasudDU, I totally agree with Mark about the torque issue if it was wound to be a 400v Delta and you wish to run it in star. I would ask the motor rewind company for their rewind data sheets. They may not mean much to you but if they don’t supply them quickly then there may be some...
  12. squeeky

    Shaft Grounding Safety Issue

    Close up of the shaft after they did some polishing. This is what started my investigation on this one.http://files.engineering.com/getfile.aspx?folder=4b82f7a8-52cf-40da-81e5-aa51ae5a5f4b&file=picture_164.jpg
  13. squeeky

    Shaft Grounding Safety Issue

    The end of the turbine hydraulic system. http://files.engineering.com/getfile.aspx?folder=4f36d988-19a6-48bd-8416-7ba56f8ab2ba&file=mvc-007s.jpg
  14. squeeky

    Shaft Grounding Safety Issue

    Going for two this time. Top bearing frosting and shaft damage.http://files.engineering.com/getfile.aspx?folder=2d66afb3-5332-4772-b8f1-dcb821884936&file=mvc-006s.jpg
  15. squeeky

    Shaft Grounding Safety Issue

    Thrust bearings. This is not a mechanical issue.http://files.engineering.com/getfile.aspx?folder=70872c88-4963-4c18-9309-422d261187e0&file=mvc-005s.jpg
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