Anyone know about AC motors?

[PottersBar]

I have an old Electrolux Hoover which has packed up.

The culprit seems to be some sort of 4 wire capacitor(?), one wire has disconnected from it. The motor is rated at 450w if it makes any difference.

The supply in connects to the capacitor with two wires (red & black) via the on/off switch and another two wires (also red & black) come out at the other end. They in turn disappear off to the windings/brushes.

Does anyone know if this is a capacitor and if so is it just there to reduce interference or is it required to make the motor start/run? Any ideas where I could buy one. Failing that, if it is only there for interference can I just bypass it, it is used so seldom that the interference would not be an issue.

Many thanks for any input.

 

[ELZ4742]

Single phase electric motors need a capacitor to energize a second-phase winding.
so you cannot just remove it

 

[holmslaw]

It's a start capacitor, it creates the initial rotation of the motor.

 

[Spark123]

As it has brushes it is probably a universal motor

Can you post a photo of the motor?

 

[ericmark]

The fact it has 4 wires likely for interference suppression this is common with AC/DC brushed motors. Although a capacitor is often used to start squirrel cage motors vacuum cleaners don't tend to use that type of motor.

Likely you can just bypass and it will work. However it may upset yours and neighbours TV and Radio including wireless broad band and mobile telephones. Most power tools drills etc. Use the same sort of device and likely you can find a replacement.

Failing that power it from a socket with filter in it which will likely do same thing.

Picture of motor type will help.

 

[PottersBar]

As it has brushes it is probably a universal motor

Can you post a photo of the motor?

 

[ericmark]

Replacements are available they look more like this

but first I would just try by-passing as likely you will not have any problems.

Most today are built into the power plug

and my hunt for type of EMC filter you have failed the closest I found was this which at £9.64 seems rather expensive and OTT for what it does.

So by-pass and switch on your radio and TV and see if it is a problem. If it is a problem then try a power tool repairer for replacement.

 

[FDJ]

Failing that power it from a socket with filter in it which will likely do same thing.
.

No!, these things must be mounted as close to the motor as possible to be effective.

Frank

 

[ericmark]

Failing that power it from a socket with filter in it which will likely do same thing.
.

No!, these things must be mounted as close to the motor as possible to be effective.

Frank

I would agree should be close to motor but many times when these have blown I have bypassed without any problems and a filtered socket must be better than nothing.

I was surprised when I tried to find a replacement that I could not find one on the internet. They must be fitted to nearly every drill and angle grinder I have worked on but when I tried to find the part listed I have failed.

Maybe you have idea where they can be got?

 

[PottersBar]

So by-pass and switch on your radio and TV and see if it is a problem.

I by-passed as suggested, works fine, no interference on anything as far as I can make out, makes you wonder why it was on there in the first place

Many thanks for all replies - job done.