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  1. Miguel Villarroel

    Aluminium Overhead Bare Conductor

    Little changes in length are fatal, you know. In this way, i referred to coefficient of expansion 10 years down the road, why i must use same coefficient to study conductor´s behavior but modulus of elasticity changes. I refer the most to overhead distribution where is common using AAC or AAAC...
  2. Miguel Villarroel

    Aluminium Overhead Bare Conductor

    Good point my friend, but internationally is accepted that after final, modulus of elasticity keep changing over time, my question is: why? it doesn´t happen with coefficient of linear expansion If there was no electricity there would be no internet. Good point, don´t you? :D
  3. Miguel Villarroel

    Aluminium Overhead Bare Conductor

    Why? in aluminium conductors elastic modulus changes but coefficient of linear expansion doesn´t change, (of course, changes over time) If there was no electricity there would be no internet. Good point, don´t you? :D
  4. Miguel Villarroel

    Beginner Question: Ground Fault Current

    It refers about delta primary distribution system in comparing with wye system, i.e. if you need to transport a bulk to some distance cross country, ungrounded delta is a plus, but if you need to share out in a dense area grounded wye is a plus; of course if you use a wye grounded to transport a...
  5. Miguel Villarroel

    Maximum Installed Lighting

    I think you should ask about minimun not maximun, why do you want to know maximun values? If there was no electricity there would be no internet. Good point, don´t you? :D
  6. Miguel Villarroel

    125 Vdc rated switch

    Why do you need to cut IEDs power? If there was no electricity there would be no internet. Good point, don´t you? :D
  7. Miguel Villarroel

    81L/H Settings for Utility Feeders

    I think you need this: overvoltage, undervoltage, overcurrent and residual, frecuency low and high, Why? the answer is power quality, Is this the most important for your facility or not? if yes, you must put it all, if not, don´t worry be happy... If there was no electricity there would be no...
  8. Miguel Villarroel

    VESDA system installed to monitor the air inside switchgear and MCCs?

    must have been the ozone that activated If there was no electricity there would be no internet. Good point, don´t you? :D
  9. Miguel Villarroel

    600V to 44KV grid tying options

    What kind of loads are fed by the grid? Do you know regulations about stations over there? If there was no electricity there would be no internet. Good point, don´t you? :D
  10. Miguel Villarroel

    cable distance transformer to switchgear

    I think DNO rules about a voltage drop border at ACB you can´t exceed, one should be the one who set the voltage profile to be used, but rules are rules If there was no electricity there would be no internet. Good point, don´t you? :D
  11. Miguel Villarroel

    Cable Tray Impedance

    you want calculate X/R value per leg, don't you? If there was no electricity there would be no internet. Good point, don´t you? :D
  12. Miguel Villarroel

    Cable Tray Impedance

    in any event that affects the type of installation is the maximum demand that can be applied to the feeder If there was no electricity there would be no internet. Good point, don´t you? :D
  13. Miguel Villarroel

    Cable Tray Impedance

    As customary in such cases is to use the effective impedance value for calculating the voltage drop If there was no electricity there would be no internet. Good point, don´t you? :D
  14. Miguel Villarroel

    Earth resistence in MV/LV network

    What kind of connectors usually use? If there was no electricity there would be no internet. Good point, don´t you? :D
  15. Miguel Villarroel

    240 volts 1-phase, 3-phase 1-line

    I think you are right with wye neutral grounded, e.g. you can serve each tenant with one leg supplying two lines and neutral, they´ll can connect 120vac or 240vac one phase loads only, and keeps three legs to move HVAC system and other 3p loads If there was no electricity there would be no...
  16. Miguel Villarroel

    Power factor controller equipment

    I suggest you to use fixed capacitors banks bonded to start system in large motors loads, it could be one per big motor too, and to use automatic compensation to help with others loads. About brand all are the same for me ... If you use local fixed at large motor each feeder will work better...
  17. Miguel Villarroel

    KVA Method Vs. Per-Unit Method

    KVA for preliminar and per-unit when designing, not worth hair-pulling If there was no electricity there would be no internet. Good point, don´t you? :D
  18. Miguel Villarroel

    Test require after fault

    OK, but how does it work? three fulltime? one or two stand-by?. Fault triggers all breakers, generators stop. If selective coordination works i think you only have to check protections, if it is a full time systems that the best chance to inspect everything. If there was no electricity there...
  19. Miguel Villarroel

    Test require after fault

    HV generator? If there was no electricity there would be no internet. Good point, don´t you? :D
  20. Miguel Villarroel

    Earth resistence in MV/LV network

    OK, Do you have one earthing systems for all, LV/MV and HV? Why every 4 years? If there was no electricity there would be no internet. Good point, don´t you? :D
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