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4 HP on 115v??
A co-worker asked my opinion of the current worksite table saws out there. He
mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
"Wayne Brissette" wrote in message thlink.net... A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? It is based on stall speed output, not real HP. It is an advertising gimmick. Check the watts for true comparison. 1 HP = 746 watts. Ed http://pages.cthome.net/edhome |
4 HP on 115v??
Hello there,
The motor is 1.5 HP. The only time it is 4 hp is during a blue moon with all the planets in alignment, with the rotor locked, for one brief millisecond, just before it blows up. Thanks, David. Every neighbourhood has one, in mine, I'm him. Remove the "splinter" from my email address to email me. Newbies, please read this newsgroups FAQ. rec.ww FAQ http://www.robson.org/woodfaq/ Archives http://groups.google.com/advanced_group_search Crowbar FAQ http://www.klownhammer.org/crowbar |
4 HP on 115v??
On Mon, 19 Jan 2004 11:39:28 GMT, Wayne Brissette
wrote: A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne That quite a bit, like running three toasters at the same time. I'd much rather have a quality fence and 1 HP, than a so-so fence and 4.4 HP. |
4 HP on 115v??
Ah, Craftsman is also that type of tool. A $200 saw that develops 3,4
maybe more hp. All on a 110 circuit. On Mon, 19 Jan 2004 13:26:45 GMT, Phisherman wrote: On Mon, 19 Jan 2004 11:39:28 GMT, Wayne Brissette wrote: A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne That quite a bit, like running three toasters at the same time. I'd much rather have a quality fence and 1 HP, than a so-so fence and 4.4 HP. |
4 HP on 115v??
Wayne Brissette writes: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material 15 amps maxes out at 2.4 HP. Unless they've invented something that changes the laws of physics, they're misleading you. |
4 HP on 115v??
Ed Pawlowski responds:
* Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? It is based on stall speed output, not real HP. It is an advertising gimmick. Check the watts for true comparison. 1 HP = 746 watts. One hore does equal 746 watts, but--that would mean the Bosch delivers 2-1/3 horses, which I am sure is high. You probably need to figure 65% of that, for motor efficiency, though it might be as high as 70%. So, at 70%, you have 1.63 HP. Which is very close to 1-1/2 HP. Charlie Self "Take care of the luxuries and the necessities will take care of themselves." Dorothy Parker http://hometown.aol.com/charliediy/m.../business.html |
4 HP on 115v??
In rec.woodworking
Phisherman wrote: That quite a bit, like running three toasters at the same time. I'd much rather have a quality fence and 1 HP, than a so-so fence and 4.4 HP. Really? I've got to let your rip some of this 8/4 white oak I have and see how fast you change your mind. Having ripped it on my 1.5HP with a Forrest WWII and on my buddies 3HP Jet with a Forrest WWII, I can tell you that HP is wonderful. |
4 HP on 115v??
On Mon, 19 Jan 2004 11:39:28 GMT, Wayne Brissette
wrote: A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne by lying.... |
4 HP on 115v??
Bruce responds:
Really? I've got to let your rip some of this 8/4 white oak I have and see how fast you change your mind. Having ripped it on my 1.5HP with a Forrest WWII and on my buddies 3HP Jet with a Forrest WWII, I can tell you that HP is wonderful. Yeah, but that 3 HP Jet is on a 220 circuit. The Bosch is a 110 machine. It does not turn out a realistic 4.4 HP. More like 1.5 which is actually sufficient for most hobby woodworking, though 8/4 oak is going to be a slow feed item. Charlie Self "Take care of the luxuries and the necessities will take care of themselves." Dorothy Parker http://hometown.aol.com/charliediy/m.../business.html |
4 HP on 115v??
That MAX hp output is weasel words, the saw is NOT a true 4+hp motor
John On Mon, 19 Jan 2004 11:39:28 GMT, Wayne Brissette wrote: A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
On Mon, 19 Jan 2004 10:04:31 -0700, Bridger wrote:
On Mon, 19 Jan 2004 11:39:28 GMT, Wayne Brissette wrote: A co-worker asked my opinion of the current worksite table saws out there. He * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne by lying.... Maybe. If I'm doing this right: 4.4HP = 3.28Kw at 100% eff. (which it isn't, of course) 3.28Kw of power at 120v requires 27 amps. Creative. I have seen other products with similar claims though. Joe Ontario |
4 HP on 115v??
Joe notes:
On Mon, 19 Jan 2004 11:39:28 GMT, Wayne Brissette wrote: A co-worker asked my opinion of the current worksite table saws out there. He * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne by lying.... Maybe. If I'm doing this right: 4.4HP = 3.28Kw at 100% eff. (which it isn't, of course) 3.28Kw of power at 120v requires 27 amps. Creative. I have seen other products with similar claims Almost all shop vacuum cleaners...I've got one that's 5 HP, another that's 6-1/2 and a 4 HP small unit, all for 110 volts. Routers. How many 110 volt 3 to 3-1/2 HP routers are there on the market? Charlie Self "Take care of the luxuries and the necessities will take care of themselves." Dorothy Parker http://hometown.aol.com/charliediy/m.../business.html |
4 HP on 115v??
|
4 HP on 115v??
In article ,
Joe wrote: If I'm doing this right: 4.4HP = 3.28Kw at 100% eff. (which it isn't, of course) 3.28Kw of power at 120v requires 27 amps. Well, on a 15A circuit, you get 15A in one wire and 15A out the other, so it adds up to 30A. Isn't that how it works? :-) |
4 HP on 115v??
I think that it has two cords.
-Jack "Wayne Brissette" wrote in message thlink.net... A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
On Mon, 19 Jan 2004 14:19:09 -0500, Roy Smith wrote:
In article , Joe wrote: If I'm doing this right: 4.4HP = 3.28Kw at 100% eff. (which it isn't, of course) 3.28Kw of power at 120v requires 27 amps. Well, on a 15A circuit, you get 15A in one wire and 15A out the other, so it adds up to 30A. Isn't that how it works? :-) That's like looking at a water pipe. Looking to the left, here comes 15 gallons per minute. Looking to the right, there goes 15 gallons per minute. Must be 30 gallons per minute flowing in that pipe ;-) -Doug |
4 HP on 115v??
15 amps @ 120 volts = 2.41 horsepoer. They lie.
"Wayne Brissette" wrote in message thlink.net... A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
Mr. Self confirmed...
One hore does equal 746 watts, but--that would mean the Bosch delivers 2-1/3 horses, which I am sure is high. You probably need to figure 65% of that, for motor efficiency, though it might be as high as 70%. So, at 70%, you have 1.63 HP. Which is very close to 1-1/2 HP. My Grizz DC is only rated at 2HP, sucking up 12 amps of 230 volt power. Let's see, crunching the numbers, the motor is capable of 3.7HP, so it's only 54% efficient. Is that a mark of poor quality, or just an overly honest appraisal of the motor's output? Joe |
4 HP on 115v??
Big Joe asks:
My Grizz DC is only rated at 2HP, sucking up 12 amps of 230 volt power. Let's see, crunching the numbers, the motor is capable of 3.7HP, so it's only 54% efficient. Is that a mark of poor quality, or just an overly honest appraisal of the motor's output? It's probably just an honest rating. I don't really know the various efficiency ratings for different types of motors, and I'm too lazy to look them up right now, but I would GUESS (let's emphasize the guess again) that 60% is pretty close to the norm. Charlie Self "Take care of the luxuries and the necessities will take care of themselves." Dorothy Parker http://hometown.aol.com/charliediy/m.../business.html |
4 HP on 115v??
"Wayne Brissette" wrote in message OK, how are they claiming to get 4.4 HP out of this thing on 115v? By useing the same math that Porter Cable uses on my 7 HP air compressor, that draws 15 amps at 240 volts! Greg |
4 HP on 115v??
This is hilarious.
4.4HP * 746W = 3282.4W 3282.4W / 15A = 218.83V If your 110/115/120V (however you want to rate it) circuit EVER reaches that, you're going to melt stuff in your house. Vpeak for 110Vrms is only about 155V. I've measured 125Vrms in the wall before, which is a peak of 177V. In short, it is IMPOSSIBLE for that saw to ever develop 4.4HP, presuming its stall current is 15A, and it is running on a household 110V circuit (and further presuming that the motor is operating at 100% efficiency, which it is, of course, NOT). Now, if it can draw 21A at Vpeak (155V) without turning in to a puddle, then it can consume power equivalent to 4.4HP, though it still wouldn't be cutting wood at that rating. "Wayne Brissette" wrote in message thlink.net... A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
Figuring in efficiency and power factor, the best it's gonna be is ~1.5hp.
-- Al Reid "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." --- Mark Twain "CW" wrote in message ... 15 amps @ 120 volts = 2.41 horsepoer. They lie. "Wayne Brissette" wrote in message thlink.net... A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
"effinperfectionist" wrote in message . com...
This is hilarious. 4.4HP * 746W = 3282.4W 3282.4W / 15A = 218.83V You are playing the same game bu using "theoretical" numbers. You have to look at efficiency and power factor to knoe the actual watts/hp If your 110/115/120V (however you want to rate it) circuit EVER reaches that, you're going to melt stuff in your house. Vpeak for 110Vrms is only about 155V. I've measured 125Vrms in the wall before, which is a peak of 177V. peak-to-opeak voltave has nothing to do with it. In short, it is IMPOSSIBLE for that saw to ever develop 4.4HP, presuming its stall current is 15A, and it is running on a household 110V circuit (and further presuming that the motor is operating at 100% efficiency, which it is, of course, NOT). the 15A is full load current (FLA) not locked rotor current. Now, if it can draw 21A at Vpeak (155V) without turning in to a puddle, then it can consume power equivalent to 4.4HP, though it still wouldn't be cutting wood at that rating. Still wrong since you are not taking efficiency and power factor in to account and you are using a ficticious voltage. The long and short of it is that on a nominal 120vac circuit, a motor drawing 15 amps will produce `~1.5 hp. On a 20 Amp curcuir you can eek out a little more at the expense of heat and speed. If the circuit is not limited, it will continue to slow down and produce more power until it hist 'breakdown' and stalls. at that point it will deaw the Locked rotor current. I am not sure why the manufacturers have taken to this silly rating game. I have a 1.5 hp Ingersol-Rand air compressor that is 1.5 HP and draws about 16 amps. The same compressor by today's 'standard' is rated at 6hp. That's great, except that in reality, they do the same amount of work for the same power input. "Wayne Brissette" wrote in message thlink.net... A co-worker asked my opinion of the current worksite table saws out there. He mentioned that he had seen the Bosch 4000 at Cosco along with the Dewalt 744. He said he was leaning towards the Bosch 4000 because it had a 4HP motor. "What? No, way!" I told him, then he proceeded to show me Bosch's web site where in fact they claim: * Powerful 15 Amp, 4.4 HP max. tool output - Power to tackle any material OK, how are they claiming to get 4.4 HP out of this thing on 115v? Wayne |
4 HP on 115v??
No, the best it is ever going to be is 2.41 horsepower. Small motors are
rated in INPUT power. "Al Reid" wrote in message ... Figuring in efficiency and power factor, the best it's gonna be is ~1.5hp. -- |
4 HP on 115v??
CW wrote:
No, the best it is ever going to be is 2.41 horsepower. Small motors are rated in INPUT power. Ha! So _this_ is how Bosch routers went from 2HP to 2.25HP without a change in the motor! -- gabriel |
4 HP on 115v??
"CW" wrote in message ... No, the best it is ever going to be is 2.41 horsepower. Small motors are rated in INPUT power. Not according to the NEC and NEMA. "Al Reid" wrote in message ... Figuring in efficiency and power factor, the best it's gonna be is ~1.5hp. -- |
4 HP on 115v??
Al Reid wrote:
"Still wrong since you are not taking efficiency and power factor in to account and you are using a ficticious voltage." No, I'm not wrong. I said IF it could actually DRAW 21A at the peak voltage of 155V, then the math gives you power consupmtion of 4.4HP. Efficiency is not relevant, as I'm talking purely about consumed power (input power). Thus, if a 21A peak coincides with a 155V peak, the power consumption at that moment is 4.4HP. I am NOT talking about power delivered to the cutting teeth, or wherever else you may choose to measure it, I'm talking about the total consumed power of the machine. And, 155V is not ficticious.......it's the peak instantaneous voltage for a 110V sine wave. (110VACrms / 0.707) To quote myself: " Now, if it can DRAW 21A at Vpeak (155V) without turning in to a puddle, then it can CONSUME POWER EQUIVALENT to 4.4HP, though it still wouldn't be cutting wood at that rating." |
4 HP on 115v??
The best the two organizations do is say that "this is what we would like
you to do". If anybody followed that, we wouldn't have 6 HP shop vacs. That's why our customers used to bring us their motors for rebuld. They could either rebuild the old 2000 HP motor or they would have to buy a modern 3500 to replace it. "Al Reid" wrote in message ... "CW" wrote in message ... No, the best it is ever going to be is 2.41 horsepower. Small motors are rated in INPUT power. Not according to the NEC and NEMA. "Al Reid" wrote in message ... Figuring in efficiency and power factor, the best it's gonna be is ~1.5hp. -- |
4 HP on 115v??
"CW" writes: The best the two organizations do is say that "this is what we would like you to do". All the more reason to use the amp rating instead of the HP rating. The amp rating is more strictly controlled. |
4 HP on 115v??
While that may be true, what is ultimately of importance is the power
delivered to the shaft of the motor. That is where HP and torque are traditionally measured. What is better, a 15A motor with a 1.5 HP output or one with a 1 HP output. Efficiency and power factor must be considered. Input power is meaningless if you want to know how much work it will do. -- -- Al Reid "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." --- Mark Twain "DJ Delorie" wrote in message ... "CW" writes: The best the two organizations do is say that "this is what we would like you to do". All the more reason to use the amp rating instead of the HP rating. The amp rating is more strictly controlled. |
4 HP on 115v??
"effinperfectionist" wrote in message . com... Al Reid wrote: "Still wrong since you are not taking efficiency and power factor in to account and you are using a ficticious voltage." No, I'm not wrong. I said IF it could actually DRAW 21A at the peak voltage of 155V, then the math gives you power consupmtion of 4.4HP. Efficiency is not relevant, as I'm talking purely about consumed power (input power). Thus, if a 21A peak coincides with a 155V peak, the power consumption at that moment is 4.4HP. I am NOT talking about power delivered to the cutting teeth, or wherever else you may choose to measure it, I'm talking about the total consumed power of the machine. And, 155V is not ficticious.......it's the peak instantaneous voltage for a 110V sine wave. (110VACrms / 0.707) It is still meaningless. It is not a DC machine. It is still rated based on the RMS input voltage. Mow if you wnnt to apply a higher (155VRMS) input voltage, then you would be correct. The only measure that has any value is the HP and torque at the output shaft. I don't care how many amps go in, I want to know how much HP is developed. To quote myself: " Now, if it can DRAW 21A at Vpeak (155V) without turning in to a puddle, then it can CONSUME POWER EQUIVALENT to 4.4HP, though it still wouldn't be cutting wood at that rating." |
4 HP on 115v??
On Wed, 21 Jan 2004 02:52:20 GMT, "Al Reid"
wrote: While that may be true, what is ultimately of importance is the power delivered to the shaft of the motor. That is where HP and torque are traditionally measured. What is better, a 15A motor with a 1.5 HP output or one with a 1 HP output. Efficiency and power factor must be considered. Input power is meaningless if you want to know how much work it will do. -- HP "where the rubber meets the road" is of course the only meaningful measurement. it's actually used in some high performance equipment, but output brake horsepower is not something I've ever heard of being measured on small electric motors. instead, the manufacturers seem to be free to engage in whatever flights of fancy they please when writing specifications. Bridger |
4 HP on 115v??
On Wed, 21 Jan 2004 02:58:00 GMT, "Al Reid"
wrote: The only measure that has any value is the HP and torque at the output shaft. I don't care how many amps go in, I want to know how much HP is developed. I doubt you will ever see that information given for a power tool. I suspect that that number would shock the american buying public, who think that they own 6 HP vacuum cleaners and such. I doubt that output HP on one of sears' 6 HP specials would exceed 1/4 HP or so.... |
4 HP on 115v??
Roy Smith writes:
Joe wrote: If I'm doing this right: 4.4HP = 3.28Kw at 100% eff. (which it isn't, of course) 3.28Kw of power at 120v requires 27 amps. Well, on a 15A circuit, you get 15A in one wire and 15A out the other, so it adds up to 30A. Isn't that how it works? :-) No. They're going in opposite directions so they cancel. You get zero amps from your 15A circuit which makes the 4.4 HP even more miraculous. Less than truth in advertising... |
4 HP on 115v??
Yes, it is. In Europe, motors are rated in watts. That rating has to meet
government standards. "DJ Delorie" wrote in message ... "CW" writes: The best the two organizations do is say that "this is what we would like you to do". All the more reason to use the amp rating instead of the HP rating. The amp rating is more strictly controlled. |
4 HP on 115v??
"Al Reid" wrote in message ... While that may be true, what is ultimately of importance is the power delivered to the shaft of the motor. That is where HP and torque are traditionally measured. What is better, a 15A motor with a 1.5 HP output or one with a 1 HP output. Efficiency and power factor must be considered. Input power is meaningless if you want to know how much work it will do. That's quite true. Why would a manufacturer want you to know the actual work that their product will do? It sounds so much better to rig the numbers. -- -- Al Reid "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." --- Mark Twain "DJ Delorie" wrote in message ... "CW" writes: The best the two organizations do is say that "this is what we would like you to do". All the more reason to use the amp rating instead of the HP rating. The amp rating is more strictly controlled. |
4 HP on 115v??
CW writes:
Yes, it is. In Europe, motors are rated in watts. That rating has to meet government standards. But it's still less than useful information because you have no idea of duty cycle or motor efficiency. Charlie Self "Character is much easier kept than recovered." Thomas Paine http://hometown.aol.com/charliediy/m.../business.html |
4 HP on 115v??
Check out this link for a series of properly rated motors:
http://www.marathonelectric.com/moto...P&MIN=15&DAT=A -- Al Reid "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." --- Mark Twain "Bridger" wrote in message ... On Wed, 21 Jan 2004 02:58:00 GMT, "Al Reid" wrote: The only measure that has any value is the HP and torque at the output shaft. I don't care how many amps go in, I want to know how much HP is developed. I doubt you will ever see that information given for a power tool. I suspect that that number would shock the american buying public, who think that they own 6 HP vacuum cleaners and such. I doubt that output HP on one of sears' 6 HP specials would exceed 1/4 HP or so.... |
4 HP on 115v??
Al Reid responds:
Check out this link for a series of properly rated motors: http://www.marathonelectric.com/moto...P&MIN=15&DAT=A Yeah, well Marathon is said to be among the best--and with the 3600 rpm 1-1/2 HP unit listing for $320, they should be! Charlie Self "Character is much easier kept than recovered." Thomas Paine http://hometown.aol.com/charliediy/m.../business.html |
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