Check your house for power vampires

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neb

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#316183 23-Sep-2024 15:33

This came from a discussion in another forum where someone was checking his house for power consumption and noticed his relatively recent LG microwave consumes over 30W sitting there doing nothing, and his NZ-made smart car charger draws 50W doing nothing, which was how much his deep freeze draws while running the compressor. Just checked here and pretty much everything is at 0.0W idle apart from the DVD player at 1.5W.

(How do you create a device that draws as much power doing absolutely nothing as a running refrigerator?).

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#3285477 23-Sep-2024 16:07

What model deep freeze only draws 50W while running?

richms

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#3285483 23-Sep-2024 16:26

A friend thought they were onto something with their microwave and also an air fryer being power hogs but their meter was not doing power factor and it was actually minimal but with a terrible power factor the VA was quite high.

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neb

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#3285498 23-Sep-2024 17:37

djtOtago:

What model deep freeze only draws 50W while running?

It's a chest freezer so that's quite probable. And the measurements of the power vampires were taken with PF taken into account, so W not VA.

elpenguino

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#3285579 23-Sep-2024 20:17

neb:

This came from a discussion in another forum where someone was checking his house for power consumption and noticed his relatively recent LG microwave consumes over 30W sitting there doing nothing, and his NZ-made smart car charger draws 50W doing nothing, which was how much his deep freeze draws while running the compressor. Just checked here and pretty much everything is at 0.0W idle apart from the DVD player at 1.5W.

(How do you create a device that draws as much power doing absolutely nothing as a running refrigerator?).

Parasitic losses in a switch mode power supply are proportional to the size of the power supply. So if your charger is , say 2kW, a 50 W idle loss is only 2.5 %. Doesn't sound so bad that way.

With a little imagination you could design the thing to shut down completely on no load.

From 2025, the EU mandates no more than 0.5 W in standby mode, which is a good thing and will trickle down to our TVs and other gadgets that don't already meet that standard.

How did you measure your appliances?

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RunningMan

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#3285581 23-Sep-2024 20:27

elpenguino:

So if your charger is , say 2kW, a 50 W idle loss is only 2.5 %. Doesn't sound so bad that way.

In that case though, it isn't a charger, it's an EVSE, so a bunch of contactors, some protection circuitry and a cellular modem. The charger's in the car itself, so 50W is quite a bit.

neb

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#3285586 23-Sep-2024 20:53

elpenguino: How did you measure your appliances?

For individual devices, just a cheap plug-in power meter. For different circuits of the house, DIN-rail-mount power meters that measure about a bunch of different parameters including reactive/apparent/true power.

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#3285587 23-Sep-2024 20:57

RunningMan: In that case though, it isn't a charger, it's an EVSE, so a bunch of contactors, some protection circuitry and a cellular modem. The charger's in the car itself, so 50W is quite a bit.

In particular it's burning over a kilowatt a day doing absolutely nothing. That's a pretty terrible design.

sir1963

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#3285602 23-Sep-2024 22:47

Freezer I wold believe 150-300 VA depending on the size of the compressor

@50 VA for the charger, it would feel quite warm

Wheelbarrow01

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Chorus

#3285605 23-Sep-2024 23:03

Our bach has everything turned off at the wall (including fridges, microwave, tv, hot water) when we aren't there. The only things powered on in our absence are the ONT, router and Eufy camera base unit.

It still ticks up about 1 kWh per day. That seems like a lot to me but I'm not going without security...

[EDIT: I lie - we also have a 20+ year old Sony stereo on standby on the same circuit as the ONT. Maybe I should unplug that and see if it makes a difference...]

djtOtago

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#3285670 24-Sep-2024 09:22

At our crib the only thing we leave running is the fridge / freezer. Genesis energy says we use 0.4 kWh per day.

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#3285685 24-Sep-2024 10:02

Wheelbarrow01:

Our bach has everything turned off at the wall (including fridges, microwave, tv, hot water) when we aren't there. The only things powered on in our absence are the ONT, router and Eufy camera base unit.

It still ticks up about 1 kWh per day. That seems like a lot to me but I'm not going without security...

[EDIT: I lie - we also have a 20+ year old Sony stereo on standby on the same circuit as the ONT. Maybe I should unplug that and see if it makes a difference...]

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richms

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#3285687 24-Sep-2024 10:05

It will be the stereo. Some of them left the main transformer running all the time rather than having a second psu powering just the control and networking logic. Audio has been very reluctant to move to switching power supplies because of some of the bad experiences with old SMPS a long time ago, people assume they all suck badly, so inefficient magnetic transformers are even today still common in audio gear.

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Wheelbarrow01

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#3285797 24-Sep-2024 13:08

richms:

It will be the stereo. Some of them left the main transformer running all the time rather than having a second psu powering just the control and networking logic. Audio has been very reluctant to move to switching power supplies because of some of the bad experiences with old SMPS a long time ago, people assume they all suck badly, so inefficient magnetic transformers are even today still common in audio gear.

Thanks for that info. I actually have a friend staying there at the moment so I'll ask him to unplug the stereo when he leaves and we'll see if that makes a difference.

RunningMan

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#3285853 24-Sep-2024 16:54

neb:

RunningMan: In that case though, it isn't a charger, it's an EVSE, so a bunch of contactors, some protection circuitry and a cellular modem. The charger's in the car itself, so 50W is quite a bit.

In particular it's burning over a kilowatthour a day doing absolutely nothing. That's a pretty terrible design.

FTFY.

If it's using 50 W, then over 24 hours it would use 1.2 kWh. Power is measured in Watts. Energy in Watt-hours. That aside, a 50 W standby usage is crazy high. A basic microprocessor and a wifi or cellular radio is all that should be required and should use a whole lot less than 50 W.

mattwnz

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#3285911 24-Sep-2024 19:33

RunningMan:

FTFY.

If it's using 50 W, then over 24 hours it would use 1.2 kWh. Power is measured in Watts. Energy in Watt-hours. That aside, a 50 W standby usage is crazy high. A basic microprocessor and a wifi or cellular radio is all that should be required and should use a whole lot less than 50 W.

My parents have some older NZ built amplifiers for their stereo system that are always powered as they are designed that way, as they take hours to fully warm up to produce the best sound. They are very warm if you put your hand on them, and they have heat sinks and grills on the box to vent heat. So wouldn't be surprised if they are 100W + when not being used. Their power bills are always quite high. Yet they are always going around turning off their lights when they are not being used

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