amp talk

[vacuumssuck213]

Today I've been looking at amps. Now all my Vacs are between 2 and 7 amps todays Vacs (race motors) are 12 and up to 14 is the highest I've seen what if anything do amps do with vacuum power a high number like 12 or 14 is just a fast spinning mother that Burns out quickly what's the magic combo?

 

[sonnyndad]

An amp is a measure of current, not power. To find power, multiply Volts x Current (Amps) x Power Factor= Power (Watts). Loads that have a higher power factor have a lower current, which is what you want. Less current means less strain on the household wiring= Fewer house fires. IMHO, a vacuum motor should not exceed 7 amps. Resistive loads naturally have a near perfect power factor of .99 or 1.0. That's good. Capacitive loads have a power factor of .4 to .6. You should invest in a Kill-A-Watt meter by P3 International. It tells you the current, volt-amps, power, and power factor of any device you plug in.

 

[kenkart]

But Really...

Amps dont mean much in regards to cleaning power, Case in point, an 8 amp Filter Queen has over 100 inches of sealed suction, more than many 12 amp machines, good design means more than the amount of current it uses...just my opinion.

 

[bnsd60m9200]

one of the best machines ever made, the convertible was only 4.3 amps for many many years. hell even kirby's only went up to 6. high amperage with modern crap is nothing but a marketing gimmick for ignorant consumers. same thing for dtd vacuums with "dry shampoo" systems back in the day, most of which were and are crap...

 

[DesertTortoise]

With canister vacuums I always wonder if the 12 amp rating I often see for them includes the amp draw of the powered floor brush. The other thing is if you look at other motor specs, very often motors that are rated around 10.5 to 11 amps maximum have very different performance in terms of air flow measured in cfm and sealed suction.

I don't think sealed suction is the whole story either. I have a 1971 vintage Kenore canister with a 2.7 peak horsepower motor (before the fixation on amps, vacuums were often rated by the peak horsepower of their motors) that is rated at 100 inches of sealed suction. Sounds pretty good, right? Yeah, but airflow is only 34 cfm. A modern Lamb motor like the 115923 has right around 100 inches of sealed suction too, but more than triple the airflow. That is four decades of technical progress in fan design speaking.

It is the combination of airflow and suction that cleans your floor and why air watts which are a mathematical combination of airflow and sealed suction through different sized openings seems to be the new measure of merit of a particular vacuum cleaner. Studying specs of motors you can see a lot of "12 amp" motors vary greatly in their air watt ratings. Some modern one stage fan motors are making significantly more air watts than many legacy two stage motors with older fan designs, and both would be rated as "12 amp" motors in a canister vacuum.

They are not necessarily spinning them harder either. One of the stated benefits of Lamb's new Advantek series of impulse motors is that the motors can be turned slower for less noise. The impulse motor in the new Kenmore Elite canister is incredibly quiet in operation.

 

[davetranter]

Amperes, Watts and efficiency

At a fixed supply voltage and roughly constant power factor for a series wound motor, The current draw will roughly equate with the power drawn from the mains supply. Unfortunately, this has little equivalence with the amount of dirt which a cleaner will extract from your flooring.

This harks back to the (mentioned in several threads elsewhere) forthcoming E.U. ban on high power/current machines which have proliferated on this side of the 'Pond' recently, being the result of either overcoming poor design by throwing more power into the system, or just the "public's" desire for ever bigger numbers on the front (just like automobiles!! ;-) )

I think my highest powered vacuum draws 900 Watts maximum. (Can't check just now, as it is out on loan :-( )

All best

Dave T

P.S. I have no idea of the approximate Power Factor of a series motor running on an AC supply. (answers on a postcard, please... ) When I studied electrical theory, our main textbook (Edward Hughes - Electrical Technology 4ed) went into very little detail about small 'universal' motors, concentrating instead on huge DC crane motors, etc.

 

[tolivac]

Power factor of small universal motors used in the home or intermittently-no importance.And for DC devices-PF doesn't apply here-PF is for AC devices only-at best for the industrial DC motors the PF could apply to the motors rectifier and power supply circuits.The PF of a universal motor on AC could be considered slightly inductive.Most power suppliers are not concerned about PF for most small motors universal or otherwise.It only when large numbers of motors or other devices are used-this could be lighting and electronic devices.This would be like in a factory,or office building or other large commercial place.And power companies relize that PF changes during the day-that is why you see PF capacitor banks on pole tops-or in substations.They are switched in-out by time-or changes in PF in the system.For some PF corrections-these are variable PF-often called "variable condensers"unloaded synchonous motors are used.Again sometimes at very large substations or really large power users at their substation-the motor is in a sealed,gas filled enclosure.The PF of this device is varied by changing the voltage and current to the motor rotating feild winding.