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Household Electricity Consumption
MonMotha:
According to the 2nd plate, your motor draws 0.75kW (750W) but 8.2A at rated load (1HP mechanical output). The 0.75kW number is likely rounded. 8.2A * 230V would give you 1.9kVA. Note that this is not 1.9kW. Induction motors typically have pretty terrible power factor. Most residential customers only get billed for actual energy consumed (hence Watt * Hours). Large commerical and industrial customers are also billed for actual energy consumed, but are often penalized for poor power factor since it costs the utility extra money to deliver that energy to you if you are consuming it with poor power factor.
Your meter may be reading VAs to you, but hopefully it's only accumulating actual Watts. Might want to check with your electric company to see how they bill. If they're billing you for reactive power (often known as VARs), I'd say you're getting shafted, but for all I know that's become typical.
The S.F. Max Amp of 9.8 says that is the maximum current the motor should be permitted to consume. The service factor (SF) of 1.4 indicates that the motor can safely output 1.4 times its rated horsepower, but you shouldn't consider that "useful" power - it's a safety factor only. The SF Amp rating would be for when the motor is operating at that 1.4x rated capacity.
Note that inrush on that sucker is on the order of 50A, so that may cause erroneous readings if you don't give it a good chance to level out.
richms:
--- Quote from: Kevin Mullins on February 06, 2009, 05:41:02 pm ---I love it when they slap a sticker on something like a clothes washer and dryer that claims to "only uses xxxkw per year"..... uh.... based on how many loads of laundry might help in that equation.
My fridge has a similar sticker, but that's a little different, once it's set it should remain a fairly consistent usage.
--- End quote ---
If you think thats bad, here they are making all new cars come with stickers that give their annual fuel _cost_ - no matter that its being up and down and now up again, They just take the manufacturers rated l/100km, some arbitary and stupidly low number of km's, and some set fuel price which was an average of some year some time ago and put a figure on them.
Most other appliances have a star rating that is common with Australia which is pretty good since they compare like for like, so a small bar fridge will always get a low rating since it has less storage so the cost per litre of storage per year is quite high.
Also if you are being billed VA's then its really bad for a stuffed fridge since the current stays pretty much constant on motors between light and heavy load, its just that they get closer to a unity power factor when they are more heavily loaded - something that screws people up when they figure that they are only lightly loading things so dont size their inverters or other supply arrangements properly.
Also, if the fridge is never turning off then its stuffed - particually if the thermostat is not making any change in its temperature. Once at temperature it just has to cover the losses thtu the sides of it, and if you open the door for ages - that should only be a few mins an hour of runtime.
Level42:
--- Quote from: Blanka on February 05, 2009, 08:53:33 am ---Found this
--- End quote ---
For some reason, I found this one quite interesting:
Mac Mini G4 1.5Ghz + Wacom A4 tablet
Power-brick plugged, computer turned off: 9 watt
System stand-by: 11 watt
Average office use: 30 watt
Importing CD to MP3: 45 watt
3D gaming: 50 watt
No name PC, Pentium IV 3.0 Ghz, Radeon X300
Turned off: 16 watt (!)
Average office use: 108 watt
Do the calculation what we would save globally if everyone switched to a Mac (mini ;)).
:D
Electricity consumption is simple: everything heated electrically uses lots amounts of energy.
Kevin Mullins:
--- Quote from: MonMotha on February 07, 2009, 03:31:03 am ---According to the 2nd plate, your motor draws 0.75kW (750W) but 8.2A at rated load (1HP mechanical output). The 0.75kW number is likely rounded. 8.2A * 230V would give you 1.9kVA. Note that this is not 1.9kW.
Note that inrush on that sucker is on the order of 50A, so that may cause erroneous readings if you don't give it a good chance to level out.
--- End quote ---
Well, we went ahead and did another test on the water well pump and came to the same conclusion that it's pulling 1.9kW. (see attached pic)
This time I shut the pump down and drained all the water from the house and lines so that it would run longer and give the most "stabilized" reading. (usually it'll only run for about 30 seconds or so otherwise) The reading did spike up a bit around 2.4 or so for just a short stint and then came back down and stayed rock solid at 1.9. So I'm gonna investigate that some more. The pump is only like 5 years old, the one before it was 20 years old when I replaced it.
There are splices that are supposed to be waterproof and all that where the pump gets tied into the main lines.....do you think a bad line or something beings it's in water could cause an extra current draw of sorts? The pump works strong as hell though. I'm trying to decide whether to pull it up just to look everything over. (it's about an 80 foot well)
I also verified a couple other appliances by looking at the data tags on them and it also kinda clarified that what I'm seeing on the meter is indeed kilowatts, or wattage in general. (it'll read from .000kW - XXXkW)
Dryer tag - 5600 watts
Our reading - 4850 watts
Hot water heater tag - 5500 watts
Our reading - 5300 watts
More to come as I go........
Kevin Mullins:
Oh..... the fridge is definitely cycling more often after turning it down to nearly a 1.
(1-9 scale)
Gonna see how things remain cold and frozen and such.
Like I've said, I've had it set on 5 for years now and just never really paid any attention to how often it cycled.
Everything was cold..... I was happy. ;D
Makes me wonder though if it's on it's way out then........
--- Quote from: richms on February 05, 2009, 05:06:37 am ---The killer I found was a fridge - as it lost its gas it was just running almost all the time - you never notice it because its still cold enough, until it finally dies and only gets cold - all while running constantly.
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