My new "5.75HP" Shopvac

shortbus

Joined Sep 30, 2009
10,045
That is a 1930 model I think. This is how the dustette looked around 1980. I have been quite puzzled how they managed to end up in that awkward situation. But I think I understand more about how now:rolleyes:
I'm waiting patiently for Loosie to tell us his story about this.:D:p:)
 

GopherT

Joined Nov 23, 2012
8,009
That is a 1930 model I think. This is how the dustette looked around 1980. I have been quite puzzled how they managed to end up in that awkward situation. But I think I understand more about how now:rolleyes:
Ah, the 1980! What a perfect design for this task.

My favorite part of the paper was the joy the scientist had while writing this conclusion....
At least two of these injuries were caused by a Hoover Dustette,
which has fan blades about 15 cm from the inlet. The present
patients may well have thought that the penis would be clear of the fan
but were driven to new lengths by the novelty of the experience and
came to grief.
 

THE_RB

Joined Feb 11, 2008
5,438
So they inflated the real number by ~6X. :eek:

That's flagrant and far beyond mere stretching of the truth. I wonder if there have been any lawsuits on this yet. Seems like a class action would be a big enough potential payout to attract some hungry lawyers.
It's very common! I did some work with woodworking routers, they are often specced in the advertising at "3.75 hp" etc, but in reality most draw a running maximum of maybe 10-11A at 115v AC. That's 1265W or approx 1.7hp in input power. And like we all know the proper way to spec a motor is in output shaft power which is lower again.

I'm not sure about Strantor's figue of 55% running efficiency for a large universal series wound motor, with a lowish ohms series winding I would have expected it to be closer to 70% or so.

But it DOES still mean the manufacturer or advertisier has claimed 4-5 times higher 'hp" than the actual engineering spec.

Of course they all have to do it, if one manufacturer lies and says their Shopvac is "5hp" and the competitior sitting next to it in the showroom says the truth claiming "1.5hp" which product is the one that sells?

So that "hp" spec has been pushed up and up way beyond any real value. It's even worse with audio amps! I've walked past tons of tiny little ghetto blasters etc with big stickers claiming "200W RMS" "250W RMS" etc, and based on size and weight they are lucky to have a 20W transformer inside, if that!

To Strantor; contact the Shopvac manufacturer, tell them you have done proper engineering measurements and found the shopvac is not having the hp as claimed. Ask them to replace it with a PROPER 5hp one, or refund 2/3 of your money. They might give you some money back just to shut you up. ;)
 

GopherT

Joined Nov 23, 2012
8,009
oh yeah, and inrush current was 25.9A with filter off and hoses removed. So even using their ridiculous method of calculating "HP" would only put this thing at 4.17HP. They must have brought the winding temp down to -20C with liquid nitrogen like it was said in the link.

I am waiting for the car companies to use the same methods to inflate their EV and Hybrid electric motor horse power ratings.

Strantor, measure the inrush current on your hybrid. You might have a 1000 HP motor on your Prius!
 
Top