Recent content by WFO

  1. W

    High power factor Is it Good/Bad? Why?

    Is a high power factor good or bad? If you are talking about evaluating the insulation of a device (a transformer for example) a high power factor is bad. Just thought I'd muddy the water a little.
  2. W

    Could 9th Harmonic Be Causing Noise on Local Telephone Company's System?

    The only industrial load is a 1200 Hp gas line pump, which does not appear to be the culprit (i.e., the harmonic still exists when the pump is down). The rest of the area is rural load. The link was good, but I was looking for something the phone company could put on their equipment.
  3. W

    Could 9th Harmonic Be Causing Noise on Local Telephone Company's System?

    We have a local telephone company complaining to our utility that they have noise on their system. We have investigated and found a fairly significant 9th harmonic on the power line. This seems to play havoc with phone systems. What is a likely cause of a 9th harmonic? We are a rural utility...
  4. W

    Rated Load: Definition & Relationship to Voltage & Current

    A transformers "rated load" is rated in VA (volts X amps), not power (since the manufacturer has no idea what kind of load will be put on it). The rating of the transformer is based on the heat build up from current flow through the windings. At rated voltage and rated amps, you would have...
  5. W

    Alternative energy sources to generate electricity?

    Geothermal. Look at Iceland.
  6. W

    What Role Do Armature and Copper Windings Play in a Motor?

    It sounds like you are describing a shaded pole motor. The copper loops provide a phase shift for torque purposes.
  7. W

    Is My Circuit Overloaded and Causing the Fuse to Blow?

    As Russ pointed out, 230volts X 10 amps = 2300watts, well below both of your predicted loads. Simply put, you have too much plugged in.
  8. W

    Topics for electrical engineering ethics

    Discuss the ethics of a professor that requires a student to communicate in electronic form but does not respond.
  9. W

    What is the resistance of meter coils?

    True, but in terms of revenue metering, assuming a plus or minus 6% variation in voltage as irrelevant to metering accuracy would be tantamount to stealing. In Texas, the Public Utility Commision requires plus or minus 2% (or less) error on house meters (most of which in practice run within...
  10. W

    What is the resistance of meter coils?

    Voltage on a distribution circuit is never constant since it will vary with load and the load is never constant. Line voltage regulators will maintain a usable voltage, not a constant one.
  11. W

    What is the resistance of meter coils?

    There are 2-wire meters that read 120 from hot leg to neutral. They also have a potential coil. The theory is the same as the 3-wire meter mentioned above, except the there is only one current coil and (as mentioned) the potential coil is 120 volts.
  12. W

    Question about balance of el. energy production and consumption

    The voltage at the generator is controlled by the excitation winding. As noted, the steam resources respond to speed, which is affected by the current draw in the line from the load. If the voltage drops, the field of the excitation winding is increased to maintain voltage. A voltage...
  13. W

    Will a Magnet Damage My Credit Card?

    Yes. The situation you described may not do it, but a magnetic field can mess up a credit card or Hotel key type device. At a recent meeting, the group toured a generator facility. Everyone that entered the room had to have Hotel desk re-do their keys when they got back. No one could get...
  14. W

    Understanding Electricity Basics: Volts, Amps, Watts, Ohms & Conversions

    http://www.allaboutcircuits.com/vol_1/index.html
  15. W

    Why Do Different Countries Use 220V@50Hz and 120V@60Hz?

    He's wrong. Edison was desperate in his attempts to discredit Westinghouse's AC system and was resorting to all sorts of public relation propaganda to prove how dangerous it was (including the promotion of the electric chair). It was hardly to Westinghouse's (or Tesla, his top engineer that...
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