Question about power tools and number of amps

davidc11291

New member
Joined
Oct 14, 2011
Messages
200
Reaction score
0
I'm looking for a shop-vac to handle my vacuuming. I noticed that most regular, household vacuum cleaners are rated at 11 amps. Does this mean that a regular vacuum cleaner has a stronger motor (and more suction) than a 5hp shop vac, which is rated at 9-10 amps, or even a smaller shop vac rated at 7 amps? I'm looking to get the smallest, most portable vacuum I can, while still having as much suction as possible.
 
Using amps as a measure would not be the way to go. Compare shop-vac to shop-vac, and I would say as "hp" increases, so will suction.
 
Vacuum Cleaner Ratings/Specifications

The main things I look for in selecting a vacuum cleaner are:

-Motor(s) input power (where the biggest consumption of the rated amperage occurs.)...Always compare: Watts:Watts...Or...Amps:Amps
(Conversion formulas: amps x 120v=watts...watts/120v=amps)

-Water Lift (called "sealed suction")... How many inches a totally sealed motor will vertically lift a 1" column of water. Good indicator of a vacuum cleaner's ability to lift/pick-up dirt/debris.
(90", or more, is considered the 'best'...But the caveat is: Vacuum cleaner prices go up exponentially as the lift-rating increases, though

-Air Flow (rated in CFM)...Probably the most important rating/specification for a vacuum's cleaning ability. The more above 100 CFM, the better.


As to:
-Horsepower (Often called “Peak Horsepower”):
This rating is obtained by removing the fan(s) from the vacuum motor and subjecting it to the maximum load possible before the motor burns out. Then, a complex formula is applied to come up with a Peak Horsepower rating. This specification is meaningless in terms of evaluating the cleaning ability of a vacuum cleaner. This is a rating that's used primarily for marketing purposes.
As such: Here's a quote from ShopVac (explanation of vacuum cleaner terminology):
"Horsepower Rating...Peak horsepower is the maximum output horsepower of a motor determined from a laboratory dynamometer test. Since peak horsepower is outside the normal operating range of a vacuum cleaner, it may not be indicative of actual air power differences when comparing two cleaners".

-Air Watts...Not to be confused with Air Flow!!
This is considered an attempt to rate a vacuum cleaner's: output power vs. input power...Just another way to cause confusion, it seems. (But even ShopVac still lists it?!?!)
[Formula used to obtain Air Watts: (CFM x Lift)/8.5=Air Watts=1 Watt...That figures!]

-Then there's always the filters, tank-size, hoses, and attachments that may reduce the efficiency of a vacuum cleaner
somewhat.


-Boils down to and depends on one's budget/needs in the: Vacuum Cleaner purchasing decision process...IMO.


BTW:
The most NEC-allowable amperage for an appliance, such as a vacuum cleaner, on a regular household (110-120/130v) circuit is 12 amps.


-Good Luck in finding a unit for your detailing purposes!!


:)

Bob
 
Back
Top