Engine HP vs Electric motor HP
Engine HP vs Electric motor HP
(OP)
Can't remember the ratio, since one is peak HP and other is constant. Jog my memory.
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Engine HP vs Electric motor HP
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RE: Engine HP vs Electric motor HP
I'm not sure about engine horsepower.
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RE: Engine HP vs Electric motor HP
HP is a unit to measure power. Power is the ratio of work made in certain amount of time.
1 HP electric = 33,013.3 LB*FT/minute =746 watts
1 HP mechanic= 33,000 LB*FT/minute= 745.69 watts
1 HP boiler =434,107 LB*FT/min = 9809.50 watts
1 HP metric= 32,549 LB*FT/min = 735.499 watts
1 HP water = 33,015.6 LB*FT/min = 746.043 watts
1 HP U.K. = 33,000.44 LB*FT/min = 745.70 watts
I hope that; 1 watt = 1joule/sec is a constant measure of power.
RE: Engine HP vs Electric motor HP
In other words: 1 HP(SI) = 75x1xg = 75x9.80665 = 735,49875 W. We use 735 W for 1 HP.
RE: Engine HP vs Electric motor HP
"Venditori de oleum-vipera non vigere excordis populi"
RE: Engine HP vs Electric motor HP
Combution engine HP rating=approx. True HPx2.5; Electric motors are rated by true HP.
RE: Engine HP vs Electric motor HP
Is it the old French Cheval Vapeur ("steam horses") you have found. The ones that explain why the Citroën 2 CV (Cheval Vapeur) had about eleven - or was it seventeen? - normal HP?
RE: Engine HP vs Electric motor HP
Could it be that about 476W of well-placed steam can make somebody's horse do his 660 pounds 1 foot in only about 1/13th of a second? ....and then there's the question of how much latent heat does a horse-boiler have,,, at, say, 6' above sea-level.
remember: An opinion is only as good as the one who gives it!
RE: Engine HP vs Electric motor HP
RE: Engine HP vs Electric motor HP
Razz
RE: Engine HP vs Electric motor HP
The horsepower rating of a motor is based on how much constant power you can put through it and have it live for say 10 years. The breakdown torque electric motors other cheap fan motors is some where around 150% to 300% of "full load" which means that you can deliberately overload the motor for short periods provided that there are periods of less than full load for the motor to cool.
Cheap fan motors have full load torque just below breakdown torque so as to get as much out of a given iron structure which keeps down weight and cost. A portable fan needs to weigh no more than a brick and not like how concrete blocks are more like birth control blocks. You only have to work as a laborer for a stonemason for a few hours to know what I mean.
Mike Cole
RE: Engine HP vs Electric motor HP
Thread237-95838
If anyone is interested, here is an update on the project I mentioned above where we replaced a diesel engine with an electric motor and VFD. We are tracking costs and productivity. It has been running 3 months now, and the raw electricity cost is $1750 less than the diesel fuel consumed in a similar operating/production period last year. The machine is a rock crusher, and the ouptput is so much more efficient that the machine is producing approx. 35% more tons-per-hour as well. There have been 2 hours of down time, only the slipping drive belts we discovered early on because the torque response of the electric motor was so much quicker. That is in comparison to the engine downtime last year of 22 hours over 3 months. The numbers are not final yet, and production quantities need to be avaeraged over a longer time frame to be meaningful, but it is looking like it was a very good idea.
"Venditori de oleum-vipera non vigere excordis populi"