> From: gene heskett [mailto:ghesk...@shentel.net] > > I blew up old bucket-vac by putting a larger diameter hose on the > intake. This raised the air flow and the amps it drew, and apparently > tripped a one time thermal fuse about 9 minutes into a 12 minute job. > > This one claims 4 hp peak but that is likely only for short term use and > this may run for a day at a time, possibly even longer. Sucking up swarf > or saw dust as my go704 works. > > I have no clue how to translate 4hp into the amps I'd see on an Amprobe > which would equal 4hp on a 125 volt circuit.
I really dislike the term HP to describe equipment as it's so misleading. We used to joke about Sears HP in shopvacs and compressors. The simple reality is that the equivalent of 1HP is roughly 750W of electrical power. Divide that by 115VAC and you get about 6.5A. That means 2HP is about 13A. Although your circuit breaker is rated at say 15A you don't find to many gizmos drawing that. Think of that space heater that is 1500W. You don't see many 1725W space heaters. So when buy a shopvac that states 4HP they are lying to you. What it means is that for a brief moment as the motor starts turning it draws way more than the breaker can handle but not long enough to pop the breaker. That number may work out to 3000W or 4HP for a fraction of a second but that's it. So the important number on the machine is voltage and amperage. Multiply to get watts and then derate it to 85% and divide by 750. Now you have real continuous HP. I'm sure someone will come up with a more detailed explanation but essentially this back of the envelope in ink calculation. John _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
