Sometimes ratings suck -[ HMM ]-
Image by Carbon Arc
Label on a circa-1991-model Eureka Mighty MIte canister vacuum cleaner destined for the recyclers. The three-horsepower figure appears to be mathematically based, using a formula taking into account its motor’s extremely fast 21,000 revolutions-per-minute speed and minuscule torque. A little bit of research confirmed this figure was meaningless; a more meaningful specification, the airwatt, was developed to provide a better gauge of performance and, in conjunction with motor wattage, efficiency.
I was lucky to find out just how fast the motor spun to look into this horsepower claim. The vacuum’s motor bearings were making loud noises, so I took it apart to try lubricating them. (My first paid job was repairing vacuum cleaners, around the time more plastic components found their way into the appliances.) I was able to get this difficult-to-service (and no longer available as a replacement part) motor running smoothly again, but only for a short time. While bench-testing the motor, I used a photo tachometer aimed at the fan hub to obtain a full-speed reading. Unfortunately, after reassembling the vacuum, the bearings started to make noise again, so I decided not to spend any more time working on the unit.
This was one of three labels on the vacuum, along with the data label and an inspection sticker on the underside.
