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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
I have a Lasko Premium 20" three-speed box fan. I'd like to know how many
watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe |
#2
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Joe wrote:
I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe If you really want to know the real numbers, rather than theoretical book numbers, which are next to useless, you can buy clamp-on amp meters for really cheap now. Then you would need an extension cord, where you (carefully!!) split the wires, leaving both insulated, so that one could be clamped around. These amp meters only work if one of the wires are clamped. If you use an extension cord, you can use it for all sorts of things around the house to see what they use too. I was really surprised at how cheap these amp meters have gotten to be. They are accurate, too. I took one over to a certifying lab and they wanted to test it for free on a lark cause they couldn't believe anything that cheap would be worth a damn. Not many years ago, they cost hundreds, now they are down to $20 or so from he http://www.harborfreight.com/cpi/cta...emnumber=42397 |
#3
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
"Vey" wrote in message nk.net... Joe wrote: I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe If you really want to know the real numbers, rather than theoretical book numbers, which are next to useless, you can buy clamp-on amp meters for really cheap now. Then you would need an extension cord, where you (carefully!!) split the wires, leaving both insulated, so that one could be clamped around. These amp meters only work if one of the wires are clamped. If you use an extension cord, you can use it for all sorts of things around the house to see what they use too. I was really surprised at how cheap these amp meters have gotten to be. They are accurate, too. I took one over to a certifying lab and they wanted to test it for free on a lark cause they couldn't believe anything that cheap would be worth a damn. Not many years ago, they cost hundreds, now they are down to $20 or so from he http://www.harborfreight.com/cpi/cta...emnumber=42397 There's much better solutions than that, especially for the novice. http://www.amazon.com/P3-Internation...4721430&sr=8-1 I have one, it does a good job of measuring voltage, amperage draw, volt-amps, power factor, watts, and cumulative kilowatt-hours. |
#4
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Joe wrote in message
.... I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe With nothing much , other than clocks on in the house , take a reading on the billing consumption meter and then 10 minutes later. Then time for 10 minutes each of the 3 settings and consequential consumption readings -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#5
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
"Joe" wrote in message ... I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe Put a low value resistor in the neutral lead and measure the volt drop, if its an AC supply and the fan is an inductive load this won't be exactly accurate - but probably close enough. |
#6
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Fan Power Consumption
On Tue, 17 Jul 2007 21:04:05 GMT, (Joe) wrote:
Lasko Premium 20" three-speed box fan http://www.amazon.com/gp/product/pro...4507&s=kitchen 170 watts |
#8
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
On Tue, 17 Jul 2007 21:46:33 GMT, Vey wrote:
wrote: On Tue, 17 Jul 2007 21:04:05 GMT, (Joe) wrote: Lasko Premium 20" three-speed box fan http://www.amazon.com/gp/product/pro...4507&s=kitchen 170 watts This is the next to useless number I mentioned in my post. It is the theoretical maximum amount based on the theoretical voltage. In the field, voltage can vary and so can the usage. I know it sounds nutty, but I've seen variations of more than 15% from the theory and that, to me, is unacceptable. If +/- 15 % is unacceptable then the clamp on ampmeter you suggested from Harbor Freight would also be unacceptable. |
#9
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
wrote:
On Tue, 17 Jul 2007 21:46:33 GMT, Vey wrote: wrote: On Tue, 17 Jul 2007 21:04:05 GMT, (Joe) wrote: Lasko Premium 20" three-speed box fan http://www.amazon.com/gp/product/pro...4507&s=kitchen 170 watts This is the next to useless number I mentioned in my post. It is the theoretical maximum amount based on the theoretical voltage. In the field, voltage can vary and so can the usage. I know it sounds nutty, but I've seen variations of more than 15% from the theory and that, to me, is unacceptable. If +/- 15 % is unacceptable then the clamp on ampmeter you suggested from Harbor Freight would also be unacceptable. Don't assume. Buy it and test it like I did. The lab said +-3%. I consider that to be acceptable. If you don't like those numbers, then buy one for $300 and compare it to what you suggest the "book" numbers are. |
#10
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
"Vey" wrote in message nk.net... wrote: On Tue, 17 Jul 2007 21:46:33 GMT, Vey wrote: wrote: On Tue, 17 Jul 2007 21:04:05 GMT, (Joe) wrote: Lasko Premium 20" three-speed box fan http://www.amazon.com/gp/product/pro...4507&s=kitchen 170 watts This is the next to useless number I mentioned in my post. It is the theoretical maximum amount based on the theoretical voltage. In the field, voltage can vary and so can the usage. I know it sounds nutty, but I've seen variations of more than 15% from the theory and that, to me, is unacceptable. If +/- 15 % is unacceptable then the clamp on ampmeter you suggested from Harbor Freight would also be unacceptable. Don't assume. Buy it and test it like I did. The lab said +-3%. I consider that to be acceptable. If you don't like those numbers, then buy one for $300 and compare it to what you suggest the "book" numbers are. You still don't know what the power factor is with that route, a lot of cheap motors are closer to 0.5 than to unity, so the calculated wattage can be nearly double what the motor actually draws. |
#11
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
"Vey" wrote in message ink.net... wrote: On Tue, 17 Jul 2007 21:04:05 GMT, (Joe) wrote: Lasko Premium 20" three-speed box fan http://www.amazon.com/gp/product/pro...4507&s=kitchen 170 watts This is the next to useless number I mentioned in my post. It is the theoretical maximum amount based on the theoretical voltage. In the field, voltage can vary and so can the usage. I know it sounds nutty, but I've seen variations of more than 15% from the theory and that, to me, is unacceptable. If its a ventilation fan exposed to the great outdoors, wind direction could easily account for a 15% variation in power draw. |
#12
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Joe wrote:
I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. For an actual measurement, you could plug it into one of these meters: http://www.supermediastore.com/kilwa...FSNFgQod3jdUtQ |
#13
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
John Popelish wrote:
Joe wrote: I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. For an actual measurement, you could plug it into one of these meters: http://www.supermediastore.com/kilwa...FSNFgQod3jdUtQ Gee, if they are down to $20 that would be a good deal, too. Last I saw them, they were at about $35-40 and I thought was a bit too much for curiosity's sake. |
#14
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Joe wrote:
I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe Hi Joe... It's going to continue to be a bit confusing... google lasko fan watts and you'll find several entries that include comsumption.... but most say 170 watts, one says 165 watts, and yet another 70 watts. There must be a rating plate somewhere on the machine or motor, though... isn't it a legal requirement? Take care. Ken |
#15
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
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#16
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Joe wrote:
I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe I have a 20" Lasko in front of me at the moment. My Kill-A-Watt says 99/136/196 watts 129/175/248 volt-amps at 121 volts And no, there is no electrical info plate or marking on any of several of these cheapie box fans that I own. Bill Jeffrey |
#17
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
In article , Bill Jeffrey
wrote: Joe wrote: I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe I have a 20" Lasko in front of me at the moment. My Kill-A-Watt says 99/136/196 watts 129/175/248 volt-amps at 121 volts And no, there is no electrical info plate or marking on any of several of these cheapie box fans that I own. Bill Jeffrey Thanks a lot, Bill. Is your Lasko a model 3723? That's the one I have (two of, actually). Also, I went to the Kill-A-Watt web site. It looks like you can't measure any appliance running at 220 volts, correct? I have a wall A/C unit in my apartment that plugs into a 220 outlet. I read somewhere that even a fairly small one of these units uses 3500 watts. I imagine that the 3500 is only when the A/C is running the compressor. So the average wattage would depend greatly on the outside temperature, I would think. --- Joe |
#18
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Also, I went to the Kill-A-Watt web site. It looks like you can't measure any appliance running at 220 volts, correct? I have a wall A/C unit in my apartment that plugs into a 220 outlet. I read somewhere that even a fairly small one of these units uses 3500 watts. I imagine that the 3500 is only when the A/C is running the compressor. So the average wattage would depend greatly on the outside temperature, I would think. I have the UK version which is not even branded, but looking at it, it's obviously internally identical to the Kill-A-Watt. It's designed for 240V but works fine all the way down to 60V so I suspect the 120V model will work on 240V but have not opened one up to compare. At any rate the power supply is a simple capacitor and zener arrangement so it would be easy enough to modify with a lower value capacitor if the zener heats up too much on 240. If in doubt, it shouldn't be too hard to get the UK model and build some plug adapters as I did, back before it was widely available in the US. I used mine to measure the draw of my 3 ton (36,000 BTU) central AC and found that the outdoor unit draws about 3500W with a power factor of 0.91. You're correct that current draw varies with head pressure which varies with outdoor ambient temperature. I doubt your window AC is bigger than 1 ton, so even with the indoor fan, I'd be shocked to see it drawing more than 2KW and really it's probably closer to 1200W. |
#19
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Joe wrote:
In article , Bill Jeffrey wrote: Joe wrote: I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe I have a 20" Lasko in front of me at the moment. My Kill-A-Watt says 99/136/196 watts 129/175/248 volt-amps at 121 volts And no, there is no electrical info plate or marking on any of several of these cheapie box fans that I own. Bill Jeffrey Thanks a lot, Bill. Is your Lasko a model 3723? That's the one I have (two of, actually). Also, I went to the Kill-A-Watt web site. It looks like you can't measure any appliance running at 220 volts, correct? I have a wall A/C unit in my apartment that plugs into a 220 outlet. I read somewhere that even a fairly small one of these units uses 3500 watts. I imagine that the 3500 is only when the A/C is running the compressor. So the average wattage would depend greatly on the outside temperature, I would think. --- Joe Hey, I found the "electrical info plate" on the Lasko. It was stamped into the sheet metal on the bottom of the fan. After being stamped, the sheet metal was painted, which obscured the stamped info so completely that the only way I can see it only with a bright light held at an angle. As near as I can tell, it says "Model 3723 (last two digits very unclear, could be almost anything) Style EC437 (again very unclear) Type 1 E20739 Listed 154C (UL symbol) 120v 2.2amp 60hz 1922.91" Bill |
#20
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
Bill Jeffrey wrote:
Joe wrote: In article , Bill Jeffrey wrote: Joe wrote: I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe I have a 20" Lasko in front of me at the moment. My Kill-A-Watt says 99/136/196 watts 129/175/248 volt-amps at 121 volts And no, there is no electrical info plate or marking on any of several of these cheapie box fans that I own. Bill Jeffrey Thanks a lot, Bill. Is your Lasko a model 3723? That's the one I have (two of, actually). Also, I went to the Kill-A-Watt web site. It looks like you can't measure any appliance running at 220 volts, correct? I have a wall A/C unit in my apartment that plugs into a 220 outlet. I read somewhere that even a fairly small one of these units uses 3500 watts. I imagine that the 3500 is only when the A/C is running the compressor. So the average wattage would depend greatly on the outside temperature, I would think. --- Joe Hey, I found the "electrical info plate" on the Lasko. It was stamped into the sheet metal on the bottom of the fan. After being stamped, the sheet metal was painted, which obscured the stamped info so completely that the only way I can see it only with a bright light held at an angle. As near as I can tell, it says "Model 3723 (last two digits very unclear, could be almost anything) Style EC437 (again very unclear) Type 1 E20739 Listed 154C (UL symbol) 120v 2.2amp 60hz 1922.91" Bill 120v 2.2amp = 264 watts Compare that to the wattage you measured ( 99/136/196 watts) and you can see why I said that whatever the plate says is not very accurate. |
#21
Posted to sci.electronics.basics,sci.electronics.repair
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Fan Power Consumption
On Thu, 19 Jul 2007 22:41:08 GMT, Vey wrote:
Bill Jeffrey wrote: Joe wrote: In article , Bill Jeffrey wrote: Joe wrote: I have a Lasko Premium 20" three-speed box fan. I'd like to know how many watts it uses, but so far I can't find any good info. No wattage info on the box or the fan, no wattage info on the Lasko website. Googling gets me wildly disparate numbers on wattage for "portable" fans. Does anyone have reasonably accurate info? It would be nice to know how many watts for each of the three speeds. Thanks. --- Joe I have a 20" Lasko in front of me at the moment. My Kill-A-Watt says 99/136/196 watts 129/175/248 volt-amps at 121 volts And no, there is no electrical info plate or marking on any of several of these cheapie box fans that I own. Bill Jeffrey Thanks a lot, Bill. Is your Lasko a model 3723? That's the one I have (two of, actually). Also, I went to the Kill-A-Watt web site. It looks like you can't measure any appliance running at 220 volts, correct? I have a wall A/C unit in my apartment that plugs into a 220 outlet. I read somewhere that even a fairly small one of these units uses 3500 watts. I imagine that the 3500 is only when the A/C is running the compressor. So the average wattage would depend greatly on the outside temperature, I would think. --- Joe Hey, I found the "electrical info plate" on the Lasko. It was stamped into the sheet metal on the bottom of the fan. After being stamped, the sheet metal was painted, which obscured the stamped info so completely that the only way I can see it only with a bright light held at an angle. As near as I can tell, it says "Model 3723 (last two digits very unclear, could be almost anything) Style EC437 (again very unclear) Type 1 E20739 Listed 154C (UL symbol) 120v 2.2amp 60hz 1922.91" Bill 120v 2.2amp = 264 watts This is not watts; it's volt-amps. Compare that to the wattage you measured ( 99/136/196 watts) You should compare it to the volt-amps he measured. Then it's not so far off. and you can see why I said that whatever the plate says is not very accurate. You are making a mistaken assumption. If you measure the current draw (amps) and the applied voltage separately, and multiply them, you get the (real) watts consumed *only* if the load is a pure resistance. If the load has a reactive component (inductance or capacitance; in this case the motor is an inductive load), then the product of volts and amps is the "apparent power" (volt-amps), not the "real power". See: http://en.wikipedia.org/wiki/Power_factor An incandescent light bulb, electric stove, electric toaster or electric blanket would be an example of a pure resistance load. Most household equipment other than heating devices, if they have motors (refrigerator, for example) or non-PF corrected power supplies (older computer or television) will have a power factor of less than 1, and will require a special type of meter (a wattmeter) to measure their real power consumption (because the load has a so-called "wattless" component): http://en.wikipedia.org/wiki/Wattmeter As they say on that page, "On an ac circuit the deflection is proportional to the average instantaneous product of voltage and current, thus measuring true (real--my addition) power, and possibly (depending on load characteristics) showing a different reading to that obtained by simply multiplying the readings showing on a stand-alone voltmeter and a stand-alone ammeter in the same circuit." Go back and look at Bill's earlier post where he gives the result of his actual measurements: "99/136/196 watts 129/175/248 volt-amps at 121 volts" You'll see that volt-amps and watts are substantially different. This is the beauty of the Kill-A-Watt. It measures both the apparent power and the true power. The apparent power (the product of separately measured amps and volts, remember) will be larger than the true power with a fan motor load, but the true power reading is what you pay for on your electric bill (if you're a typical residential customer). Large industrial customers pay a penalty if the apparent power they consume is larger than the true power, but ordinary residences don't. |
#22
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Fan Power Consumption
Having some issues with the landlord over your utility charges?
FBt |
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