The dog hair in our house acts a bit like the lycopodium powder in the classic Kundt's tube experiment, it seems to accumulate in places where the air is undisturbed like behind doors and under chairs. When we bought Ben we read in a book that Gordon Setters don't lose their hair, THIS  IS A LIE or else someone keeps sneaking into our house at night throwing in handfuls of black dog hair.  Because of the dog hair we have to vacuum quite a lot so we have several small vacuum cleaners strewn around the house like the one in the photo. When ever I plug the vac into that plug the circuit breaker switches off, however I discovered that if I reduce the speed of the motor before I plug it in then the circuit breaker doesn't pop, once started I can turn up the speed and hoover away. It's a classic example of back EMF, when the motor coil isn't turning their is no induced EMF to oppose the increasing current so the current flowing through the coil is large, large enough to pop the circuit breaker. The speed control is probably a potential divider which reduces the PD across the coil and hence the current. The thing I don't understand is why the manufacturer added the speed control. Maybe they were expected problems with circuit breakers as this is the only time I turn it down from full speed.