Electronics > Beginners
ABC News posted a story re: Jacked Mains Voltage is increasing power bills
optoisolated:
So... wont make any tangible difference for anything digital, motors, or resistive (heating) loads with thermostats... So, basically everything? Nice job, ABC. :-DD :popcorn: :bullshit:
Berni:
Well it does make a difference with brushed motors as they will run a bit faster but im pretty sure your blender or angle grinder don't make up that much of the total power usage in a home.
Besides they have more oomph when overvolted so that's only a good thing.
jmelson:
--- Quote from: optoisolated on November 08, 2018, 03:22:24 am ---My main query with this article is how much impact does the voltage actually have on the cost of the energy supplied? The article simplifies it too much IMO. Does this come down to one of those Power Factor discussions? My understanding was that even if the voltage increased, resistance on especially passive appliances remains constant, therefore current would drop.
--- End quote ---
The meters multiply instantaneous voltage times instantaneous current to give instantaneous power.
Some devices (computers, induction motors) draw roughly constant power, so raising voltage reduces current.
Heating devices and old incandescent light bulbs draw more current as voltage rises, so they draw more current.
If you increase voltage 10% above nominal, power draw increases by 21%, and the meter will accurately record that.
This guy's electric bill must be QUITE impressive for the increase to be $1200.
Jon
nali:
--- Quote from: mzzj on November 08, 2018, 09:39:50 am ---Goddammit, where is the Ohm's law when needed?
8% increase in voltage causes 16,6% increase in power and that's what you pay for in the imaginary case of passive, constant-on resistive load.
(Of course that case is 400% unrealistic but anyways)
--- End quote ---
Don't forget that resistance will also increase due to higher temperature. Out of curiosity I measured it on an old car headlamp bulb I have lying around, for an 8% increase (12.00 > 12.96V) gave a power increase of 13.45%
optoisolated:
Guy has a lot of kettles. :-DD Or a lot of sunlamps ;) :popcorn: 8)
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