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ABC News posted a story re: Jacked Mains Voltage is increasing power bills

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vk6zgo:

--- Quote from: BradC on November 08, 2018, 02:30:51 am ---I keep tabs on 2 of our 3 phases here (Perth) with a pair of APC UPS and a couple of modbus power meters. The UPS are about +/- 1.5V and the power meters are better than 1V accuracy (I check and calibrate them every 2 years).

4-5 years ago we were seeing peaks of up to 270V on a warm summers day. Halogens do *not* like that. The grid has got it under better control over the last couple of years, but we still see north of 250V regularly.
My current 24 hour power graph shows an average of 240-242V, a minimum of 234, a maximum of 249.4 and we're currently 240-243 on the two phases.

(edit after verifying specs) Of course in WA we are 240 +/-6V (now. When I were a lad it was a *real mans voltage* at 250V). I didn't realise the East coast is 230V -6/+10.

--- End quote ---

Yes, it was 250v.
Everything worked OK, until the light globe manufacturers decided that making globes in Australia was a "mugs game".
Unlike the 240v Oz made ones, the imported ones often lasted less than a year, so "260v" ones were imported & sold at a considerable markup.
They weren't measurably better, so much whinging ensued, until the then, SECWA, at great expense, changed the supply voltage to 240v

The light globes didn't last much longer, but by now, compact fluorescent globes were being pushed hard, as having longer life, as well as being more efficient.

The younger people had never seen the old type incandescents with a decent length of life, so fell for the pitch.
Compact fluoros were pretty dire, as were the first generation LED globe replacements, but finally, LEDs are now quite good.------if you don't mind the RF interference they generate! ;D

Brumby:

--- Quote from: sibeen on November 08, 2018, 05:20:39 am ---So our standards in Oz changed. The voltage didn’t, it has stayed a nice healthy 240 volts or thereabouts :) From memory the old standard was something like 240V plus/minus 10%.

--- End quote ---

Yes- the Australian standard changed in 2000.  Before the change it was 240V +6% -10%.  To become more in line with Europe, it changed to 230V +10% -6%.

Do the math ... have a laugh.  I smiled when I did.......

A bureaucratic master stroke.

BradC:

--- Quote from: vk6zgo on November 08, 2018, 06:51:50 am ---No it's power over time (kW/h), so if the duty cycle is reduced, less power is used in that time period.

--- End quote ---

I think you missed the bit where the voltage went up, therefore the current went up, therefore the power went up. I'm pretty naff at communicating, so I probably was unclear.

We are talking about an appliance with a thermostat. It wants a kilowatt hour whether it gets it in 30 minutes or 40 minutes. More power from the resistive element means you need it on for less time to get the same energy output, so the duty cycle decreases but the billed power remains the same. My argument is an increased voltage results in more power output from the device. You are billed on power. On a device with a thermostat it's a moot point, but on something like an incandescent lamp then you are being billed for more.

Now, do I think his figures are hysterically inflated? Sure.

Our summer power bill is about $1200 for the 60 day period. Even if every device in my house was resistive and uncontrolled there is no way know to man I could account for even $100 extra for that period. So yeah he's talking out of his arse, or the ABC reporter has got it wrong (wouldn't be the first time).


--- Quote from: vk6zgo on November 08, 2018, 07:42:11 am ---The younger people had never seen the old type incandescents with a decent length of life, so fell for the pitch.

--- End quote ---

I used to buy a couple of boxes of them every time I stopped over in Qatar or Dubai. Proper long life incandescents. I've not been there in a few years now and I used the last lamp a couple of months ago. I'm now onto the "halogen" equivalents which last 1/4 of the time (and even less if they are dimmed unlike real incandescents which last *longer* when under-driven).

JackJones:
"After he realised the scale of the problem he started a company that specialises in filtering out extra voltage in homes and businesses."

I wonder how they do it? Big Clive released an interesting video recently, if you connect the secondary of a transformer in series with the primary, depending on which way it's connected you either add or subtract the secondary voltage to the mains:


You could do it like this locally without having to tinker with any utility transformers or anything dicky like that. I wonder if you could adjust the secondary somehow based on the mains, that way it would regulate the voltage to the desired value.

mzzj:

--- Quote from: optoisolated on November 08, 2018, 03:41:28 am ---In fairness if a kettle starts using more power, its going to boil quicker, and therefore, be on for less time. could an 8% increase in voltage make that much difference though? If his power bill is ~$1000 as he says, then even if you assume 100% passive appliances, then his power bill should have been $926. Something doesn't add up in this story.

--- End quote ---

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)

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