How to Replace Numatic (Henry) Carbon Brushes

Hi I'm Matt from eSpares, and in this video I'm going to show you how to replace the carbon brushes on a Numatic Henry vacuum cleaner.

Now what is a carbon brush? Well I've got a Flymo motor here I can show you like on any electric motor electricity needs to get from the outer fixed part to the central spinning shaft or armature. You can see the brushes, one on that side and one on that side and they're in contact with this brass ring at the top, it’s called a commutator.

So why do we use carbon in our brushes? Well graphite is a really good conductor of electricity which is obviously very important, but it also creates very little friction as it rubs against the commutator. Now even still that does mean that the carbon brush will wear down over time, as you can see from this carbon brush in this old Cebo vacuum cleaner that's worn about halfway down. But if it was worn all the way down then your motor will start to run intermittently and eventually will stop running altogether.

Now if that's happened to your Henry hopefully you can replace the carbon brushes. Now I say hopefully because not all Henry's use the same motor. Numatic have been making Henry since 1981 and over the years they have used lots of different parts even in Henry's with the same model number, including something like half a dozen different types of motor so how do you know which motor you've got and what type of carbon brush you need?

Well the only way is to open your Henry up and have a look at the motor type and the brushes that it takes. Now unfortunately on some of these older motors like this one the replacement brushes are just not readily available and the motor wasn't designed for easy replacement of brushes, you can see the end here it’s just soldered on. Now if that's the case it's probably time for a new Henry.

Now on Henry motors that you can easily replace the brushes you may find that you've got these open sprung type or even easier still these cartridge style ones, and it's these that I'm going to be replacing on this Henry HVR 200.

Now safety first do make sure you unplug from the mains before you do any work on any electrical appliance.

I'm going to start by taking the top of Henry's head off, now I'm going to separate out the cable rewind mechanism and outer casing from this part here which houses the motor. It’s just four screws here that need to be undone, then it's just these three screws to separate out the two parts of the motor housing. Okay there we go, there is the motor and I can just uncouple the two connect wires. From there we can see the two carbon brushes that we're going to replace.

So if you've got any plastic casing like on the top here then you can get that out of the way, then I just want to remove this first spade clip, you might just need to get in there and work it off with a screwdriver, and then just need to remove this bracket which is holding the carbon brush in place.

You'll see that these carbon brushes go in dead straight and dead perpendicular against the commutator, so it means it doesn't matter which way around you put them on. Some actually go in at an angle like that and you'll find that the end is tapered, you need to make sure that you get the right one on the right side.

I'll put the new one into place put its holding bracket on and once that's done up, I just need to reattach the spade clip. Always make sure that you replace both carbon brushes at the same time so they ware down evenly. There we go that’s that one done, ok that’s the other side done.

Now all we're going to do is to put everything back together again, and there we go new carbon brushes on a motor in this Henry vacuum cleaner. Carbon brushes are available for all makes and models on the eSpares website.

Thanks for watching.