Truth About Blender HP

[JustyBear]

Hi All,

So I saw the threat about the VitaMix, and I apologize in advance for creating a new thread, but I wanted to get this somewhere everyone can see (instead of being buried under 150+ comments).

I think I saw someone go into the physics of it briefly, but it wasn't in detail, so I am going to explain why you shouldn't trust the manufacturer's HP rating on their machines.

Basically, the manufacturer writes what the peak HP of the machine is. Essentially, they are telling you the pure potential of the blender itself. With that in mind, it is misleading because in many instances, your blender will not reach that horsepower. Why is that?

Horsepower is a measure of the power of an engine. In order to measure the power of the engine in your blender, you need to look at the WATTAGE of your machine. In order to find the wattage, you will need to make a calculation of AMPS times VOLTS.

The average household home has 120 volts, so we already know V. If a machine is rated at 3.0HP but it only has say 13 amps, you are looking 1560 watts.

1560 watts can be converted to horsepower by multiplying by .00134, which gives you 2.09.

2.09 HP? That's not 3.0 HP! Technically your machine could go to 3.0 if they inreased the amps in your machine.

The VitaMix only has 11.5 amps. That's equivalent to 1380 watts, or 1.85 HP.

Just a thought.

Ciao.

[dcrb]

I went with the VitaMix quite some time ago. Didn't choose it because of power. Reputation and it has been around since the 1920's. That was enough for me. Simply put, it works and works well. Still have the old beehive Osterizer. But it earned its retirement a year ago after 30 plus years of never fail service.

[JustyBear]

My Google-fu is weak! Alton Brown posted a link on twitter a while back about this topic, and I remember reading it and being blown away.

Here is the link with a more in depth talk about what I said: http://www.rawfoodsupport.com/read.ph...

Au revoir.

[TeRReT]

Really, really doesn't bother me. Vitamix is hands down the best kitchen equipment I've ever used, save for maybe a Robocoupe processor, both are the only two items to be the same in every professional kitchen I'e worked in and both are the only two things that never needed to be repaired or replaced, literally not a single repair in many years experience. Both have always provided the result required regardless of the task. I can't be bothered with semantics, it can do 3hp in the right conditions, thats good enough in my books. My car likely doesn't get the hp it technically in very specific conditions should, it doesn't get exactly the mileage as advertised, I'm over it.

[Dave5440]

That rundown is full of holes, What they fail to mention as you did, that a motor (be it gas , electric or diesel) only produces the HP as it's needed, so if you run the blender empty the amp draw will be low hence the wattage will be lower as well, if you start increasing the load on the motor the amp draw will increase as will the wattage now if you increase the load to to what your outlet will supply(15amps)it will trip the over load, now if you take that blender and plug it into a 20 amp circuit it will give you your 3hp(18 amps) if you could acutally load it up enough to require the full HP rating. Where are you getting this "if they inreased the amps in your machine." from it makes no sense as the amps come from the outlet.

[mikie]

"...as the amps come from the outlet."

Amps are limited by the outlet, well actually the circuit, ie circuit breaker or fuse, but electric motors are raited by amps. The more power, to a certian extent, the more amps the motor can draw, but there are also inefficiencies that alter this. However typically a small motor that will not see heavy loads is low amps and a larger motor that typically sees heavier loads has higher amps.

[Dave5440]

" if you increase the load to to what your outlet will supply(15amps)it will trip the over load, now if you take that blender and plug it into a 20 amp circuit it will give you your 3hp(18 amps) if you could acutally load it up enough to require the full HP rating."

What part of that didn't you read, and the poster seems to think the "amps" are built in to the appliance hence the dumbing down

[DiveFan]

@mikie is correct about the 'inefficiencies'. Power output at the blade will always be less than power input.

One unmentioned factor is the design of the 'power train'. The motor speed will be geared down to increase torque. A proprietary part of the design relates to the inherent tradeoff between torque and rpm. Other more subtle factors include blade and container shape, etc.

Ultimately the proof is in 'the using' and then considering, is it good value for you?

[Dave5440]

@mikie is correct about the 'inefficiencies'. Power output at the blade will always be less than power input.

Oh you mean perpetual motion hasn't been perfected yet?

[mikie]

What I'm talking about is this: Together the inputs: voltage and current, and the efficiency, determine the power output of a motor which is expressed as watts. Power is calculated by the formula Volts x Amps x motor efficiency = 12v*10a* .90 = 108 watts output (losses = 12w)

The energy which isn’t converted into motion becomes heat. This heat, or rather the amount of heat relative to the motors ability to cool itself (surface area and mass), determines how much power the motor can be made without causing damage.

So jsut because you have 120 V and a 15 Amp circuit, doesn't mean your motor can make 1800 Watts.