What should Residential 220 volts be

Discussion in 'General Electronics Chat' started by JC80, Jul 15, 2012.

  1. JC80

    Thread Starter New Member

    Jul 15, 2012
    What is too high for household 220 volts.
    Two days ago had new,residence, sewage pump to sand mound installed. Tech measured 246 volts at pump and showed concern enough that I called the power company. They said someone would be out . Received call from pwr co tech/electrician stating 246 ok. No 220 since 60's. Pump motor would like higher voltage. He had 253 at his house all time. Pump said 230. Received invoice from installer with notation of 246 volts measured. Is this CYA for what might be considered over voltage. Then at bottom they said pump manufacturer said max 250. Do I have a complaint with power co to get better 220 volt regulation. Can't afford replacing @ $2,000 new pumps. Thanks
  2. bertus


    Apr 5, 2008

    I see you are living in the USA.
    In the wiki this is stated:

    For power applications the voltage is double, so between 228 and 252 Volts, should be "normal".

    Here is the full wiki article:

  3. #12


    Nov 30, 2010
    Confirming. Today's standard is 240V +/- 5%
    Straight from the power company, Progress Energy.

    Still, I wonder why they changed the standard.
    Motors don't seem to object but the heater in my 1970 clothes dryer burnt out so many times that I redesigned it to use a Calrod instead of nichrome.
  4. BillB3857

    Senior Member

    Feb 28, 2009
    The standard in the US has changed over the years. When I was a kid, it was 110VAC, then it became 115VAC, then 117VAC, and is now 120VAC. The power companies can deliver more wattage at the same current by raising the voltage levels.
  5. JC80

    Thread Starter New Member

    Jul 15, 2012
    What should residential 220 volts be ? Thanks to all for your comments. Guess I'll have to e-mail them to the two pump installers. Will not concern myself with the 246 volts.
    Agreed: Only dumb question is the one you don't ask! Thanks again
  6. Audioguru

    New Member

    Dec 20, 2007
    The installer noted that the voltage was too high. So when the cheap (but marked-up to be expensive) Chinese pump fails then it will not be replaced under warranty.

    They KNOW that it is not reliable and will fail soon.
    Last edited by a moderator: Jul 16, 2012
  7. KL7AJ

    Senior Member

    Nov 4, 2008
    Most motors should run cooler, assuming you reduce the current commensurately. :)
  8. #12


    Nov 30, 2010
    Good solution! Now, how does the owner of a motor reduce the current commensurately?
  9. takao21203

    Distinguished Member

    Apr 28, 2012
    What about 500W halogen lamp?
    Or primary from a transformer.

    This should drop some volts.
  10. vk6zgo

    Active Member

    Jul 21, 2012
    The standard 240volt supply in the USA is somewhat different from the sorts of supply common in Europe & Australia.

    Situated on the power pole is a transformer with a 240v centre tapped secondary.
    For normal installations,the centre tap is used as a Neutral line,& the two opposing (180 degrees out of phase) ends of the winding provide separate standard 120V (w.r.t Neutral ) feeds throughout the house.

    Some devices require 240v supplies, so for those,the two (180 degree out of phase) feeds are combined to produce the required voltage.
    a 240V socket hence,has two "hot" pins,each at 120v w.r.t Neutral /Earth,

    Occasionally phase to phase of a normal 3ph supply, at 208V is used,but this is not near as common.

    A small trap for Australians & others using USA sourced 240v equipment,is the possibility that mains filters,etc, may only be sufficiently rated for 120V w.r.t Earth.

    European sourced 220V equipment usually has plenty of margin ,& will run for years on 240+ V.
    The mains supply in Western Australia used to be 250V,& faults due to overvoltage were quite rare.
  11. grahamed


    Jul 23, 2012
    What does "reduce the current commensurately" mean? And why would it make a motor run cooler? Under what circumstances? What are you talking about?
    #12 likes this.