Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Power Bill

  1. Feb 18, 2010 #1
    I live in India . I have Three Phase Line in my Home & Single Phase Line in Office . However the rates for both Single Phase & Three Phase are the same ( Rs.2.70/unit for first 50 units , Rs. 3/unit for next 50 , Rs. 3.60/unit for next 100 , Rs. 4.20/unit for next 100 & Rs.4.70/unit thereafter ) . How is this possible ?Maybe some Electrical student can explain to me . I am from Commerce Background but from what I understand from Internet , Three Phase has 3 wires & Single Phase has 2 wires . Somehow , shouldn't Single phase be costing less per unit ? Please Elaborate .

    Also what is difference between an ElectroMagnetic Electricity Meter & a Static Electricity Meter ?
    Last edited: Feb 18, 2010
  2. jcsd
  3. Feb 18, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi rahulkhajuria! Welcome to PF! :smile:
    No, because they send you the same votlage, and the same power, but they split it into three wires that are out of phase.

    See http://en.wikipedia.org/wiki/Three-phase_electric_power" [Broken] for details. :wink:
    Sorry, don't know. :redface:
    Last edited by a moderator: May 4, 2017
  4. Feb 20, 2010 #3
    most 3-phase services use 4 wires : A, B, C, plus a grounded neutral
    most 1-phase services use 3 wires : L1, L2, plus a centre-tap grounded neutral

    electricity meters measure the total electrical energy, usually displayed in kWh

    older electricity meters were electroc-mechanical, and used an eddy-current motor to spin a disc (rotor) linked via gears to a set of indicator dials. Different meters (3ph vs 1ph) have different coil arrangements, but the end result is total kWh

    newer electricity meters utilize digital electronics and eliminate the error due to mechanical friction & inertia that increases over time.

    http://www.archive.org/details/electricalmeter00assogoog" [Broken]
    Last edited by a moderator: May 4, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook