Bench Grinder problem

[Chisteve]

I have a Sealey 8 inch bench grinder, when using it today together with dust extraction etc it tripped electrics in my workshop

I reset the trip and tried it tripped again so confirming it’s the grinder that’s gone puff, I’ve not had a chance to look at it yet but thinking it’s going to be unrepairable

Just wondering if anyone has any knowledge on these things on what to check with a volt meter ? as it’s been good till today, although I’ve worked it hard - I’m no electrician - but any pointers would be appreciated

It must be electrical as did not suddenly stop just tripped the electrics

 

[okeydokey]

A couple if simple checks.
Plug the grinder into a different socket see if it still trips
Plug something else into the socket to check thats ok also see if the wires in the plug are tight as if one is loose/intermittent that could cause a trip

 

[thetyreman]

how old is it? it could be the capacitor needs replacing inside, I replaced one in mine after about 4-5 years, it's also worth checking the fuse in the plug.

 

[TomGW]

If it has done plenty of work over the years it could simply be needing a new set of brushes.

 

[Chisteve]

Thanks for the reply’s it’s not the socket will hopefully have a closer look at it shortly hopefully it might be the bushes as didn’t smell burnt out, it came to me second hand and as noted I’ve worked hard for the last couple of years will keep you updated

 

[dizjasta]

I think you will find that the grinder has a brushless motor and no replaceable carbon brushes.

 

[thetyreman]

it's a very common problem that the capacitor goes and needs changing, that is more likely the problem, have a look inside.

 

[Chisteve]

I think you will find that the grinder has a brushless motor and no replaceable carbon brushes.

I’ve found a parts diagram and seen it has no brushes so hopefully the capacitor

 

[Inspector]

Try carefully spinning up the wheels by hand, then turn it on. If it does so without tripping breakers then the capacitor need replacing. If it trips the breaker then something else electrical is happening.

Pete

 

[Chisteve]

Try carefully spinning up the wheels by hand, then turn it on. If it does so without tripping breakers then the capacitor need replacing. If it trips the breaker then something else electrical is happening.

Pete

Yes I’m aware of this as it went pop when using suggesting it was not the capacitor - planning to have a look at it today

 

[pe2dave]

Another way to reduce the load, remove the stones / pads to take the strain off.

 

[Chisteve]

Finally had a look at it - it’s terminal I think will need a rewind, oh well looking for another one now

But going to enquire cost of rewind though

 

[okeydokey]

Depending on what you need the grinder to do Screwfix do a Titan grinder for only £49.99 or Record Power for £110 - my son has the RP version pretty good for the money
https://www.recordpower.co.uk/product/rsbg8-8-bench-grinder-with-40mm-whitestone-with-uk-plug

 

[throbscottle]

I would have thought the cost of rewinding would be greater than the cost of replacement.
Going back to that capacitor, it's likely to have gone short circuit, hence tripping the c/b.. Try starting the motor with it disconnected. Should run in either direction if you give it a spin. Caps very rarely fail open (almost never).
Of course you may have a shorted winding in which case as you say, terminal.
You could always do what I did, make you own out of a hair dryer! (Bit underpowered though)

 

[Sachakins]

Depending on what you grind, if its general rough grinding any of the cheapo will do, I had screwfix one for years.
But since wood turning I opted for the Axminster 8" wide wheel, AW200ASG. Excellent for sharpening my gouges and fine tools, so much quieter and virtually vibration free.
Kept the screwfix for everything else, like cold chisels, metal shaping etc ie rough work only.

https://www.axminstertools.com/axminster-workshop-aw200wsg-wide-stone-grinder-230v-107685