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Recent content by bigbillnky

  1. bigbillnky

    Yaskawa C2553 data

    I am looking for motor data and dimensions on a Yaskawa, Type VBOZN-BY, 75 HP, C2553 frame eddy current motor, manufactured in 1984. Any help would be much appreciated. Internet searches have been fruitless. Bigbillnky,C.E.F.....(Chief Electrical Flunky)
  2. bigbillnky

    DC motor running slow. How to ID concerns

    Do these motors have a wound field? If so, the field current could be the cause of the speed variation issue. I would test the field current with the motor running and make sure that it matches the motor nameplate. Typically, diode failure in a controller that has a seperate power supply...
  3. bigbillnky

    latched input

    bigheadted I know 120 volts into a DC input card will permanently latch the input. I saw it done TWICE in a row by the same technician. He did not appreciate the humor I found in the situation, but we ALL make mistakes (especially me at times). Bigbillnky,C.E.F.....(Chief Electrical Flunky)
  4. bigbillnky

    motor failure

    humbleuser The windings of a correctly-connected motor that failed from single-phasing will be easy to spot. If it was wye connected(most likely), two of the three stator windings will be charred. If it was delta connected, only one will be charred. If the motor failed due to an overloaded...
  5. bigbillnky

    Area classification

    dtoo Is not gasoline dispensing pumps outdoors also? Seek help from a local engineering firm. Bigbillnky,C.E.F.....(Chief Electrical Flunky)
  6. bigbillnky

    Electric lake?

    skogsgurra Very interesting post. I especially love the photo of the guys "grounding" the lake. I believe you will find some very interesting things happening in that lake. You do not mention the depth of the lake and the proximity, if known, between the pipes that terminate in the lake...
  7. bigbillnky

    Cheap & dirty sump Control

    tulum Goodafternoon, The cheapest and easiest way is to use 2 fixed limit switches, a float ball mounted on a stem, and a ATL starter. The bottom limit switch closes when the float ball raises up due to an increase in level and provides power to the common side of both the top limit and the...
  8. bigbillnky

    " Do nothing machine" skills testing machine

    Rodneyjax Goodmorning You would probably find it interesting to know that these machines are still used by companies to test mechanical aptitude. Hard to believe but true. Bigbillnky,C.E.F.....(Chief Electrical Flunky)
  9. bigbillnky

    DOUBLE DERATING PER CODE ?

    EEAOC I admit I did not do the calculations, but 4/0 seems to be way oversized, all things considered. Voltage drops in the NEC are recommendations only, not a requirement. Keep in mind that local codes CAN require compliance with voltage drop limitations. Refer to the AHJ if in doubt. Yes...
  10. bigbillnky

    2 speed single phase ac motor winding connections

    arcelectric Morning, Have you tested the capacitor? A resistance check of the windings is not always a good indicator of their internal condition. A winding analyzer is your best bet. Just out of curiosity, what is the nameplate HP, RPM, and voltage? Has this motor been rewound, and...
  11. bigbillnky

    switching neutral in single phase motors?

    dave11282 Goodmorning You are questioning whether or not to break the neutral conductor, yet later you refer to the voltage as 240 volt. It is a very rare motor that requires a neutral at 240 volt. Are you sure of the voltage? One other point is that when you install a motor that requires a...
  12. bigbillnky

    NEC question - Roofing over outdoor Primary Subs

    nsbelectrical Goodevening. Maybe I can help answer your specific question. I find no specific article in code that would prohibit an awning over a transformer. Code does require that adequate ventilation is provided to prevent the transformer from exceeding the max temperature rise as stated...
  13. bigbillnky

    MTW vs. THHN

    Hello robbm, Unless you need to practice your cursing, I would not recommend THHN. Control cabinets wired with THHN are very difficult to work in. When the wireway covers are removed and the wire disturb, THHN tends to "eject" itself from inside the wireway(and I do mean eject). This leaves the...
  14. bigbillnky

    Motor Starter Problems

    vosstire Goodafternoon. I would suggest upgrading the starter to a NEMA rated starter. I have had considerable problems with Moeller in the past, so much so I totally avoid them. In all fairness though, comparing IEC rated equipment to NEMA is a night and day difference. This will more than...
  15. bigbillnky

    Is FLC for motor the same with or without VFD?

    Hello skbutler My suggestion would be to check shaft speed at 60hz(a high quality stroboscope is the best, most reliable means of checking speed that I have found). Compare this reading to motor nameplate speed. It is also best to measure the voltage, current, and frequency readings at the same...

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