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  1. waross

    Panel/Switchboard voltage matching

    Avoid shared neutrals on the lighting circuits. A feedback on an open neutral will be lethal and you may find yourself testifying at an inquest. I saw an industrial plane where someone saved money on cables by sharing neutrals. It was condemned. Rather than abandon and replace all of the...
  2. waross

    Sizing Generator- Florida Nursery

    Please stick to Tugboat applications. I have seen dozens of dependable 6 KVA sets. There are hundreds of 6 KW sets servicing Alberta's oil patch. My own standby (ex oil field) set ran up about 18,000 hours before I acquired it for standby use. My other standby set, presently out on loan and...
  3. waross

    Sizing Generator- Florida Nursery

    Sorry. That is not a high leg vector diagram. The Scott connection was originally developed to transform and convert between two phase systems and three phase systems. About 50 years ago there was a flurry of Scott derived lighting transformers to transformer 480 VAC to true 120/208 VAC with...
  4. waross

    Sizing Generator- Florida Nursery

    Like it or not, life is hard for a standby generator. I have yet to find a customer willing to pay extra to make life easier for a standby generator.
  5. waross

    Ceiling fan issue

    Not a bad idea, but also try swapping the feed to the control.
  6. waross

    Manager Says Keep the Restraints — I Think They’re Unnecessary. Who’s Right?

    I envy you. I had one boss who often had me thinking; "I don't know why, but for some reason God must want this guy to be rich."
  7. waross

    Sizing Generator- Florida Nursery

    BE VERY CAREFUL FUDGING. More than once I have spec'ed a standby set very close for a known load. I spec'ed but didn't order nor did I have a chance to vet the order before shipping. Ordered was a specific KVA at 120/208. Shipped was the spec'ed KVA but at 120/240 wild leg. So now I have a set...
  8. waross

    Manager Says Keep the Restraints — I Think They’re Unnecessary. Who’s Right?

    Engineering 101: The boss is not always right but he's always the boss. But do get a memo or something in writing. Or send a Memo; "This is to confirm our conversation of the 3rd of April, 2025. etc."
  9. waross

    Air India 787 crashes on take off

    There is more than one technique to develop full generator/alternator output at varying speeds. And, consider an alternator or generator designed to deliver full output at the slowest speed and designed to withstand mechanical forces at the highest speed.
  10. waross

    Sizing Generator- Florida Nursery

    Duke Energy 230 3-phrase power (I am told this is the highest we have available) ???? I thought that 230 3-phrase power died with the Dodo. Do you have a niche open delta wild leg service? Some guesses based on incomplete information: Simple calculation based on 120/208 V service. 30 KVA. Based...
  11. waross

    Ceiling fan issue

    A Wild Assumption Guess: Control is wired in the neutral. A small part of the winding is shorted to ground.
  12. waross

    Ceiling fan issue

    Or it may be a fsulty speed control.
  13. waross

    Phase-earth fault in YNd11 step-up transformer while operating at no load

    The neutral connection is probably providing ground current detection. What are the primary voltages? Line to line and line to neutral? It is possible to have equal line to neutral voltages along with unequal line to line to line voltages. This is quite common in long rural lines with mostly...
  14. waross

    Phase-earth fault in YNd11 step-up transformer while operating at no load

    Any unbalance in the incoming power and the delta will cause a neutral current. This may be misinterpreted as a ground fault be the protection.
  15. waross

    Phase-earth fault in YNd11 step-up transformer while operating at no load

    Unbalanced primary phase voltages or pri9mary phase angles.
  16. waross

    Corrosion on cable trays.

    We always used Spray on Electrical Insulating Varnish on all ground connections. The bolt corrosion appears to be atmospheric corrosion. Try Stainless steel bolts.
  17. waross

    DC Motor Drive - Imbalanced input (line/neutral) and output (motor + / - ) current

    The most likely cause, but not the only possibility: Someone servicing the brushes accidentally caused a short to ground from one of the brush holders.
  18. waross

    DC Motor Drive - Imbalanced input (line/neutral) and output (motor + / - ) current

    Yes. Common practice and a requirement of most codes. Yes. First at the motor. Note, there may be an alternate ground path if the motor is mounted on steel connected to structural steel. If the tech's have a DC clamp meter, measure the current in the PE conductor. A long shot, disconnect the...
  19. waross

    Commutator marks in DC Motors

    Does that make the commutator burning a design issue? Rule of thumb for sparking/arcing at the commutator. Move the brushes to cover the sparks. So when we cover those sparks may we expect sparking at every second alternate bar? Or, do we split the difference and go with minimum sparking at each...
  20. waross

    Spain and Portugal power grid collapse

    Is this a new name for "Pole Slipping"?

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