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  • Steve Ward
    Steve Ward replied to a topic in the forum Electrical Engineering:
    My search of the IEEE library did not result in any papers on this topic.
    If the bus bar ampacity is based on 1000 amps per square inch the bar is good for 63ka.  The problem is with the support system.  The insulators supporting the...  more
  • Rex Falk
    Rex Falk posted a topic in the forum Electrical Engineering:
  • Chadwick Rife
    Chadwick Rife replied to a topic in the forum Electrical Engineering:
    Elevators may be supplied from emergency systems and air condition from non emergency. Feeders should be installed in separate conduit.
  • Willy Reinhart
  • Juan Pena
    Juan Pena replied to a topic in the forum Electrical Engineering:
    I reckon that it depends on the fuse norm. The new codes always provide the rms value of the steady-state symetrical current and the code stablish to do a test that the device it is not going to be destroyed with the value I''k. Sometimes the code tell...  more
  • Carl Coulter
    Carl Coulter replied to a topic in the forum Electrical Engineering:
    Matt Franks said:
    What is the general rule to size a fuse. 200kVA, 525A, 220 Volt. The minimum SLG fault is 950A?

    The general rule is to size the fuse such that the trip curve is outside of the start up currents, inrush, locked rotor, steady state...  more
  • Carl Coulter
    Carl Coulter replied to a topic in the forum Electrical Engineering:
    Disclaimer:  I've never worked on a transformers with a conservator, which are the only ones I have seen that have Buchholtz Relays.
    One of the lessons we got from Three Mile Island was, "Believe  your instrumentation."
    Setting that aside, I...  more
  • Dennis Alwon
    Dennis Alwon replied to a topic in the forum Electrical Engineering:
    Here is something to be careful with these water heaters.  If it is a residential one it is usually not an issue but if the water heater is 5kw rated at 240 volts and you connect to a 208 volt system you would then have about 75% less wattage at...  more