Another one of those Motor questions

[Michael GilliganParticipant @michaelgilligan61133]

My paper-shredder has finally failed me

It’s an Intimus 280 CC built in 2006 and has served me well

[ multi-lingual instructions here ]

https://kb.quadient.com/~/media/kb_neopost_com/products/shredding+systems/destructeurs+-+fr/standalone+media/operations/user+guides/manuel+utilisateur+taros+2510-2810.pdf?sc_lang=fr-fr

After continuously working it for several hours yesterday it started to falter, and the motor was quite warm.

I opened it up, assuming that the cutters had become clogged … but it all cleaned-up easily, so I tried it again: motor hummed but didn’t run.

All the mechanical side is fine, but there is a surprisingly complex-looking little circuit board which may, or may not, prove to be part of the problem.

So let’s start with the more comprehensible stuff:

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I have electrically  disconnected the motor and powered it directly from the mains using the black and grey wires … As hoped, it hums but doesn’t rotate until I spin it up by hand: So presumably the starting problem is down to that capacitor.

My real question therefore is … What purpose does the white lead serve ?

I haven’t yet found a data-sheet for the motor, or any details of the PCB

… is it likely to be for current sensing ?

Thanks for any thoughts

MichaelG.

 

 

[Michael Gilligan]

On 8 April 2024 at 14:37 Michael Gilligan Said:

Thanks for any thoughts

Do you have continuity from the white terminal on the motor and both of the others? (Maybe a few tens or hundreds of ohms?)

If not, I suspect that the device marked ‘T.P.’ is a thermal fuse that has gone open circuit. (It will likely be in intimate contact with the motor windings somewhere – possibly buried.

I think that the main supply for the motor is supposed to be between white & gray. My **guess** is that the black may be something to do with a start or reversing circuit.

[Ian PParticipant @ianp]

Whilst it may spin the way you temporarily wired it up, I doubt it will produce much power as the two windings are in series.

If you have no means to test the capacitor why not connect temporarily wire up the motor as per the diagram on its laminations, putting 240V across white and grey and the capacitor between black and grey. It will either start and run or it will just hum.

Just humming means its 99% the failed capacitor. If it runs then you can turn your attention to the PCB.

Ian P

 

[duncan webster 1Participant @duncanwebster1]

If it was a blown thermal fuse I wouldn’t expect it to run or hum. My shredder goes both ways, if Michael’s does then I suspect it’s like a Parvalux motor, where for one direction you apply volts to grey, for opposite to black. Capacitor is permanently in series with one or other winding. Quite why it needs all the electronics is another question entirely. If my guess is correct resistance grey/white and black/white will be equal.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, both

To be honest, I wired it as I did because it was easy to just pull the connectors off the capacitor, and I wanted to try “something” … I will have another look this evening [or maybe tomorrow].

Andy’s point about TP probably being Thermal Protection definitely needs checking sooner rather than later.

MichaelG.

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Edit: __ both should now read all three !

[john fletcher 1Participant @johnfletcher1]

Like Andy has already said, I think the TP is a thermal fuse buried some where inside the motor windings, which is normal on these type of gadgets and could be faulty. if you are able to lift one of the capacitor leads and test using an ohmmeter between White and Black, if all OK then the thermal fuse is sound. The capacitor can also be faulty, I see an 8 micro on the label, so one from a five foot fluorescent could be used as a substitute for testing purposes. Just be very careful with capacitors as good one will hold its charge for a long time, short out the terminals with an old screw driver.  in fact just for testing purposes almost any cap will be OK providing it of 400 working volts or better, definitely not an electrolytic. John

[Frances IoMParticipant @francesiom58905]

I found that chinese thermal fuses were a common cause of early motor failure but after near 20yrs I suspect a more serious failure has stalled the motor which then overheated – usually just buried under top layer of insulation.  you may be able to feel for it and cut very carefully the insulation to remove it from circuit then try white and grey as power

 

[Michael GilliganParticipant @michaelgilligan61133]

O.K. folks … I couldn’t contain my enthusiasm [despite having opened the thing up five times already] so I’ve had some coffee and got the meter out.

First let’s confirm, yes the motor is [as mentioned in the instructions] bi-directional.

With no other connections, I have done some approximate resistance measurements with my old analogue meter:

Motor Black to Motor Grey is 60 Ohms

Motor White to Motor Grey is 30 Ohms

Motor White to Motor Black is 30 Ohms

… ergo : I think TP might just be ‘Tapping Point’ or some-such.

but if it is a thermal fuse, then it hasn’t blown. 🙂

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For completeness, I have also taken a photo of the top of that PCB

… the long blue piece is a reed switch that detects the presence of the collecting bin.

… I presume the Yellow capacitor has something to do with the direction-switching.

… the little Orange brick could be a relay [need to get a better image of it]

… the Grey connector goes to the optical detector

 

MichaelG.

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[Michael GilliganParticipant @michaelgilligan61133]

Dreadful photo, but I think it shows all the important numbers

MichaelG.

[Les Jones 1Participant @lesjones1]

Hi Michael, Connecting the  mains to black and grey is NOt the corrrect way to check the motor. With the black grey and white wires from the motor NOT connected to the cirguit board connect one side of the mains (Say neutral.) to the white wire. Connect live to the black wire. The motor should rotate in one direction. Then transfer the live to the grey wire. the motor should then rotate in the other direction. (If it just hums then the capacitor is nost likely the cause of the problem.)

NOTE The capacitor must still be connected to the black and grey wires from the motor for this test.

Les.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for the correction, Les

… in my defence, I was only trying to test that the windings were intact, which clearly they are.

I haven’t got it in me to dismantle the thing again tonight 🙁

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Seems like that style and rating of capacitor is commonly used on Tumble Driers

… but whilst browsing ebay, I found this one:

https://www.ebay.co.uk/itm/175872785326

Would it do any harm to go up from 8uF to 10uF

… and is there anything especially good about ICAR

?

MichaelG.

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P.S. __ whilst trawling ebay, I also found this:

https://www.ebay.co.uk/itm/275371242819

which presumably explains the purpose of the yellow capacitor on my PCB

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, T.P. on a circuit diagram, could mean a “Test Point”, which may just be for factory setting/checking, or even service use. The little yellow capacitor, could just be for radio interference suppression.

Regards Nick.

[Speedy Builder5Participant @speedybuilder5]

I never knew shredders were that complicated.  Forward / Reverse, current overload check, check bin, auto check for something to do, and motor speed.  Looking at the circuit board, there must be over 80 electronic components there. I think the designer lost the plot or perhaps never had a plot to loose in the first place.

Back in the day, we had a larger office shredder which used to eat 4 part computer printouts with interleaved carbon paper. It failed one day after probably 10 years service. I had a look in the “control box” to find a couple of chocolate box connectors, a capacitor and a neon light and that was about it.  The failure was a microswitch that had dropped off as the screws had disappeared into the shreddings. New 6Ba screws and it continued its service for many more years.

[John Doe 2Participant @johndoe2]

It does seem very complicated. Why does it need any electronics? Ours runs on for about 5s after all the paper has cleared, but that’s about it. Could be done with a capacitor across the relay coil.

 

The electronics are probably for snooping on you, and sending scans of everything you shred to some foreign power………..

Using a shredder for several hours, as the OP says was likely to be the cause of this demise. I don’t think small domestic ones are designed for that sort of constant use ? I find that occasional application of teflon spray into the cutter rollers helps.

[NealebParticipant @nealeb]

Not always the “over-complicated electronics” that fails. Our shredder – “no more than 3 mins in 30 mins” – still has a working motor. Still has all the electronics in working order. Pity one of the gears in the gear train broke into three pieces…

[Les Jones 1Participant @lesjones1]

Here is a link to data on the small relay.

I think the yellow capacitor 0.47 uF capacitor drops the mains voltage down to to a low level for the electronics befor it is rectified and regulated to supply the electronics. ( It will have a reactance of about 6.8 K ohms at 50 hz.)

 

 

The blue track shows the path of mains neutral via the relay contacts to the white motor wire. The brown track shows the path of mains live to the black or grey motor wire via the rocker switch which selects the motor direction. The other pole of the rocker switch seems to rout the output of the 0.47 uF capacitor depending on the position of the rocker switch

Les.

[Michael GilliganParticipant @michaelgilligan61133]

Full disclosure … for the benefit of those criticising the design:

We bought it in 2006

It wasn’t cheap but it has worked hard, and proved to be worth every penny

I had one major jam-up several years ago [plastic film clogged the cutter assembly … my own fault for shredding the printed mailers in which  MEW was delivered at the time] … There is an old thread on this forum about that.

Until Sunday, nothing else had caused the slightest concern, and nothing had broken.

Sunday was quite warm here, especially in the conservatory, but I shredded something like 1500 sheets of A4 that day, before noticing that the body of the shredder was feeling a bit warm … having near-enough finished what I planned to do, I left it to cool down … it was only when I switched it back on that the motor failed to turn and simply hummed.

I opened-up the unit and confirmed that everything was mechanically sound and working correctly … hence my question posted here and my quick & dirty test of the windings.

Hopefully, everything will work when I replace the capacitor … but I won’t know until I try.

Having been suitably chastised by Les, I will check the windings in the manner directed … sometime this evening.

MichaelG.

[Les Jones 1]

On Les Jones 1 Said:

Here is a link to data on the small relay.

I think the yellow capacitor 0.47 uF capacitor drops the mains voltage down to to a low level for the electronics befor it is rectified and regulated to supply the electronics. ( It will have a reactance of about 6.8 K ohms at 50 hz.)

< etc. >

Many thanks, Les … that is most helpful

MichaelG.

[Robert Atkinson 2Participant @robertatkinson2]

Disconnect white, black and grey wires (the ones going to the motor and 8uF capacitor) from the PCB. Using a safe connecion method connect white wire to live 240V supply and either black or grey to neutral.
INSULATE the unused wire!
Apply power and motor should run one way. Changing the wire connected to neutral should run the other way.
Given your previous tests if it does not run like this the capacitor is faulty.
A 10uF capacitor will work OK but is not ideal.

The TP device marked on the motor IS a Thermal Protector. From your previous tests this does not appear have tripped.

Robert.

[Michael GilliganParticipant @michaelgilligan61133]

With special thanks to Les and Robert for keeping me Safe and Sane, I am pleased to confirm that the Motor [given a mechanical push-start] runs well, in both directions.

The capacitor, however, is obviously as dead as a Norwegian Blue Parrot.

Having disconnected and removed it … I found this reasonably clear hint that something is amiss :

.

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Off to look for a suitable replacement now

… having duly noted Roberts opinion that I should stick with 8uF

 

MichaelG.

 

[duncan webster 1Participant @duncanwebster1]

Let the experts confirm Here

This problem keeps coming up, is it possible to test capacitors by connecting in line light bulb across the mains? If so can someone suggest value for bulb?

[Les Jones 1Participant @lesjones1]

Testing the capacitor by connecting it in series with a light bulb will give a very rough indication if the is faulty. An 8uF uf capacitor will have a. reactance of about 400 ohms at 50 hz. I would suggest using a 100, 60 or 40 watt bulb. (An old fashioned filiment type bulb. The bulb should light but not quite as bright as it would be connected directly to the mains. (a 50 watt halogen bulb should also be OK to use.)

Here is a link to one source for an 8uF capacitor on ebay.

Les.

[MacolmParticipant @macolm]

The electronics will include the function to continue running the motor so as to clear shreds after paper is past the input sensing switch.

[noel shelleyParticipant @noelshelley55608]

A good multi meter will test capacitors ! Noel.

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