Thread: Suppression Capacitor on Power Tool.... Please HELP !!!

I once had the same problem.

https://www.woodworkforums.com/f13/me...ll-foto-95748/

Originally Posted by dakotax3

I once had the same problem.

https://www.woodworkforums.com/f13/me...ll-foto-95748/

Thanks for the thread link Dakotax3 ! In fact that's the most comprehensive discussion I found on this matter. Did you successfully obtained the original part with the same values?

Double post

Yes. Thanx to the posters on here I had enough information to learn more. I was then able to email Metabo with a specific part no. to seek it's cost and availability. In a return email was quoted $20 Aust and the part was in stock. The catch was this was from a Metabo wholesale distributor and I could not buy direct from them. With part number in hand I visited my local tool dealer who included Metabo in his stock. He knew nothing of the part, nothing of the internal workings of the drill, nothing on how to find a part number for this very specific item but none of that mattered as I simply gave him the part number and an order to supply it; he had no idea what it was. Again, it didn't matter. I picked it up less than 2 weeks later at the price quoted.

It was a simple matter of inserting the part into the drill with the help of a schematic diagram.

I have to say here prior to me posting on WWF I had just about given up on finding someone who could help. Retail sales outlets appeared to be just that, sales outlets not conversed with part sales. Repairs shops would not talk to me without exhorbitant costs so the whole thing was shelved for quite some time. My point is this: there are people around, including on here who are knowledgeable and conversant in a whole range of topics. Seek and ye shall find.

Thanks go to those who helped me.

Originally Posted by dakotax3

Yes. Thanx to the posters on here I had enough information to learn more. I was then able to email Metabo with a specific part no. to seek it's cost and availability. In a return email was quoted $20 Aust and the part was in stock. The catch was this was from a Metabo wholesale distributor and I could not buy direct from them. With part number in hand I visited my local tool dealer who included Metabo in his stock. He knew nothing of the part, nothing of the internal workings of the drill, nothing on how to find a part number for this very specific item but none of that mattered as I simply gave him the part number and an order to supply it; he had no idea what it was. Again, it didn't matter. I picked it up less than 2 weeks later at the price quoted.

It was a simple matter of inserting the part into the drill with the help of a schematic diagram.

I have to say here prior to me posting on WWF I had just about given up on finding someone who could help. Retail sales outlets appeared to be just that, sales outlets not conversed with part sales. Repairs shops would not talk to me without exhorbitant costs so the whole thing was shelved for quite some time. My point is this: there are people around, including on here who are knowledgeable and conversant in a whole range of topics. Seek and ye shall find.

Thanks go to those who helped me.

$20 is pretty bloody expensive for a capacitor.

If you have no joy with AEG parts you should be able to find it or an alternative.

I'd say the best bet is to try Radio Spares (RS) or Farnell (now called element14) here in Australia, I believe they also have Asian/Oceania outlets, they tend to have more stock than say Altronics or Jaycar, who I've never seen stock those capacitors.

I can guarantee to you though you would be able to get it from the US, been able to get all sorts of parts before. Digikey and Mouser have a massive range, the hardest part will just be finding it amongst all their other stuff.

If you like I can dig up my digikey catalogue, it's about the size of a phonebook.

Only issues though is there is no guarantee that it's just the capacitor that is faulty. It may be the symptom of a bigger or much worse problem yet the only obvious scapegoat without further investigation.

Originally Posted by dakotax3

Yes. Thanx to the posters on here I had enough information to learn more. I was then able to email Metabo with a specific part no. to seek it's cost and availability. In a return email was quoted $20 Aust and the part was in stock. The catch was this was from a Metabo wholesale distributor and I could not buy direct from them. With part number in hand I visited my local tool dealer who included Metabo in his stock. He knew nothing of the part, nothing of the internal workings of the drill, nothing on how to find a part number for this very specific item but none of that mattered as I simply gave him the part number and an order to supply it; he had no idea what it was. Again, it didn't matter. I picked it up less than 2 weeks later at the price quoted.

It was a simple matter of inserting the part into the drill with the help of a schematic diagram.

I have to say here prior to me posting on WWF I had just about given up on finding someone who could help. Retail sales outlets appeared to be just that, sales outlets not conversed with part sales. Repairs shops would not talk to me without exhorbitant costs so the whole thing was shelved for quite some time. My point is this: there are people around, including on here who are knowledgeable and conversant in a whole range of topics. Seek and ye shall find.

Thanks go to those who helped me.

$20 is pretty bloody expensive for a capacitor.

If you have no joy with AEG parts you should be able to find it or an alternative.

I'd say the best bet is to try Radio Spares (RS) or Farnell (now called element14) here in Australia, I believe they also have Asian/Oceania outlets, they tend to have more stock than say Altronics or Jaycar, who I've never seen stock those capacitors.

I can guarantee to you though you would be able to get it from the US, been able to get all sorts of parts before. Digikey and Mouser have a massive range, the hardest phttps://www.woodworkforums.com/newreply.php?do=newreply&p=1258817art will just be finding it amongst all their other stuff.

If you like I can dig up my digikey catalogue, it's about the size of a phonebook.

Only issues though is there is no guarantee that it's just the capacitor that is faulty. It may be the symptom of a bigger or much worse problem yet the only obvious scapegoat without further investigation.

Originally Posted by dakotax3

Yes. Thanx to the posters on here I had enough information to learn more. I was then able to email Metabo with a specific part no. to seek it's cost and availability. In a return email was quoted $20 Aust and the part was in stock. The catch was this was from a Metabo wholesale distributor and I could not buy direct from them. With part number in hand I visited my local tool dealer who included Metabo in his stock. He knew nothing of the part, nothing of the internal workings of the drill, nothing on how to find a part number for this very specific item but none of that mattered as I simply gave him the part number and an order to supply it; he had no idea what it was. Again, it didn't matter. I picked it up less than 2 weeks later at the price quoted.

It was a simple matter of inserting the part into the drill with the help of a schematic diagram.

I have to say here prior to me posting on WWF I had just about given up on finding someone who could help. Retail sales outlets appeared to be just that, sales outlets not conversed with part sales. Repairs shops would not talk to me without exhorbitant costs so the whole thing was shelved for quite some time. My point is this: there are people around, including on here who are knowledgeable and conversant in a whole range of topics. Seek and ye shall find.

Thanks go to those who helped me.

$20 is pretty bloody expensive for a capacitor.


OP

If you have no joy with AEG parts you should be able to find it or an alternative.

I'd say the best bet is to try Radio Spares (RS) or Farnell (now called element14) here in Australia, I believe they also have Asian/Oceania outlets, they tend to have more stock than say Altronics or Jaycar, who I've never seen stock those capacitors.

I can guarantee to you though you would be able to get it from the US, been able to get all sorts of parts before. Digikey and Mouser have a massive range, the hardest phttps://www.woodworkforums.com/newreply.php?do=newreply&p=1258817art will just be finding it amongst all their other stuff.

If you like I can dig up my digikey catalogue, it's about the size of a phonebook.

Only issues though is there is no guarantee that it's just the capacitor that is faulty. It may be the symptom of a bigger or much worse problem yet the only obvious scapegoat without further investigation.

$20 expensive... Agreed. But the drill was effectively u/s without it and had been lying unused in it's box for quite some time. Besides, it had seen relatively little use and I was quietly confident after inspecting it the other components were in good condition. To be honest, $20 was an incidental cost compared with the time it remained unserviceable. In the end I was grateful.

Not sure if this helps but my water tank pump recently had the start / run capacitor fail. The only place I could get them from was Wiltronics. Search for them and you may find something which helps. Ran backwards after replacement, so reversed the capacitor connections and now works ok.

Cheers,

Tom

True.

OP this might help at least in sourcing a non AEG replacement.

http://www.vishay.com/docs/49259/emi_rfi.pdf

Specifically the section on capacitors.

and then:

http://www.vishay.com/docs/28144/selguide.pdf

Given that and the capacitors values and extra leg, seems to me that it is actually multiple capacitors built into the 1 package.

If they prove hard to get, it *should* be reasonable to expect that discrete capacitors can do the same job. Probably do it better, it just comes down to if you are capable of re-wiring it and that there is space in the case for them.

I'm a security tech so I know quite a bit about DC electronics but motors and AC aren't my strong points, hope I'm helping though.]

I've found some, although all are radial not axial:


Vishay - 250v, Y2, Radial, MKT

http://www.vishay.com/docs/26526/f1710250.pdf

Can get 2200pF exactly.

Vishay - 275v, X1, Radial, MKP

http://www.mouser.com/catalog/specsheets/mkp3361.pdf

0.22uF is the closest match

Great! Many thanks to all feedback and advices.

@ dmaher
Thx for the catalogue and the sources, unfortunately, sourcing from abroad would be my last option. Since the custom clearance for importing goods would sometimes double the item's price. I might try to contact my friend in Aussie for this option. I'll PM you if I need those phone number. Thanks so much.

@ dakotax3
Thanks for the procedures of ordering parts from the original manufacturer, and for the price indication for such capacitor. And thanks again for sharing your though... I agree & that's why I might hunt for this caps till the last resource .

@TomH
From what I read so far, the capacitor that you deal with is not the same as what I'm after. In other words, the Starting/running capacitor would different with this Suppression capacitor.


To MODERATOR and ADMIN :
Don't worry, I'm not going to do anything dangerous by taking into account / taking for granted to ALL suggestions that'll be posted here, and FULLY understood your disclaimer!. I have more than enough technical background regarding this issue. Thx.

HCIM et Al.
Last year I was in a similar position with a bosch electric hammer power drill, it too had been unused for a period of about 18 months and the first time i used it it went bang. The suppressor cap blew up. I contacted Bosch, just around the corner in Clayton and the tech said that it could be ordered in from Germany at about the same price as you were quoted. However, a power drill repair technician said that for many drills he had simply left them off without any undue problems. i took his advice and haven't had any problems with interference when in use. BUT I am not recommending that you do the same.

Regards

Mike

Yes, I did wonder about that myself. A lot.

Hi Mich and others,

i wrote several posts on suppressor caps already, here's a rerun in a nutshell:

a switched-on electric motor also acts as a generator. This generated voltage is highest at max rpm (no-load idle) and it always flows in reverse of the mains voltage. The reverse voltage goes against the flow of the intake voltage and acts against it, partly cancelling it out. So it is responsible for the motor's lower power intake at idle speed and the increasing power intake at load situation (rpm drop). At lower rpm, the generator effect decreases and thus more mains fed power is allowed to flow through the motor coils.

At moments where high current, maximum mains voltage sine wave peak and a sudden circuit break (brush bounce or switch-off) coincide, the generated reverse voltage can reach 600 Volts or more. Ultrashort power breaks happen all the time while a motor is running (dust between brushes and commutator strips or shock load like in hammer drills), with brush sparks being the visible evidence of it. The suppressor cap is there for the absorption and deminishing of this effect, but the bombardment of reverse voltage spikes gradually decays the capacitor's insulation layers until a spike flashes over internally, causing a tiny short-circuited partition. The next time a machine with such a damaged capacitor is switched on, there is a burst of shorted energy inside the capacitor, vaporising parts of its contents. This is the explosion. On average only the cap needs to be replaced and there is no damage to the motor, but there may be damage to built-in electronics, since the electronic components also conducted the unforeseen very high short-circuited current burst added on top of the nominal running current.

The capacitor is there to absorb the very short en violent reverse voltage spikes caused by ultrashort interruptions (visible as brush sparks). By absorbing the spikes, the cap also deminishes the sparks and this is favourable for undisturbed radio and tv reception. The function of the suppression of sparks and therefore suppressing crackling noise in radio sound and fizz in tv pictures, has given this cap its specific name.

Conventional suppressor caps contain an X and a Y component. The X-part is connected directly across the motor terminals, so in effect it is connected in parallel to the motor's leads. X can literally be read as "cross" here. The value of the X-component is usually between 0.047 and 0.3 uF (microFarad), which is the same as 47 to 300 nF (nanoFarad). The value depends on motor power, motor rpm and the predicted intensity of sparking for that particular tool (application and design). Coffee bean grinders (sealed 100 Watts motor in relatively clean air and 12.000 rpm max) have X-caps of 47 to 68 nF. Heavier tools with drawn-through ventilation and powers up to 1000 Watts show values of 100 to 270 nF (0.1 to 0.27 uF). Heavy angle grinders (2000 Watts plus and dust laden air) usually have caps of 0.3 uF or more. A jig saw vibrates a lot and will suck in dust (high chance on brush sparking), so 0.2 uF is a logical value, in spite of the motor power being far less than a 1000 Watts.

The Y-component is a "high frequency filter" , providing more bandwidth for the quenching effect. It consists of two very small capacitors connected in series. This set of two small caps is connected parallel with the X-cap, but there is a third wire attached to the connection where the two small caps meet in the middle. This third wire is a "mass" wire and is supposed to be connected with the motor's metal bulk. Usually the XY-cap's third wire is connected to the stator's (field's) iron. "Mass" is not to be confused with "ground"; it has nothing to do with a 3-wire cord and mains plug, as the power tool is double insulated! Picture the two small filter caps skwered on the two upper prongs of the letter Y, which come together in the branch pointing down, which can be pictured as the third mass wire.

The Y component has to comply with stricter (higher) insulation standards, because mains voltage can be transfered to the motor's metal bulk when one of the small caps fails (short-circuits). If the X-cap fails, the short-circuited energy will blow up the cap itself until the mains' power fuse trips, but there will be no electrocution hazard for the user through transfering voltage to the motor's bulk, as is possible with Y-caps.

So the X-component is the main absorption and suppressing component and the small Y-caps provide a specifically designed bandwidth filter, precisely dedicated and matched to the main X-value. As broadcasts have gone digital and receivers are many times better than they used to be (filtering out reception pollutions by themselves), the bandwidth Y-component is no longer as important as it used to be in the days of "waves-through-the-air". More and more tools are factory-fitted nowadays with X-caps only, with 0.1 and 0.22 uF being the most widely used values.

It is no problem to subsitute the original 0.2 uF specimen by a 0.22 uF item, since these cap type are on average off the mark by 5 to 20 % anyway. If 0.1 uF is the only value available, you can take two of these and solder them in parallel. Your saw will work fine with just an X-cap of around 0.22 uF. It is, however, not recommended to run the tool without a cap. Without it, there is nothing to quench the reverse voltage spikes. So the brush sparking will be more violent, the brushes and commutator will wear quicker and cause yet more sparking as brushes and commutatoer gradually become more pitted and deteriorated. Also, the nasty voltage spikes will continually be present in all the copper wire coils. In a severly heated-up motor, these spikes can ultimately be responsible for a quicker flash-over acroos wire insulation layers, which is the beginning of every motor short-out. Frequent voltage spikes will ruin the electopnics, too. So, always replace an exploded cap in a tool. In your case, you may also want to check the electronics. A further hint: do not operate the saw before you have replced the cap. Running the trigger switch electronics with a shorted motor is like running a sound amp with shorted speakers. The semiconductors inside will fail within seconds and if you're baffled by the price of a suppressor cap, wait until you see the price of the rev trigger switch (which must be an original and separately ordered part)!

As for build types, the shape of the cap is not important. They can be cylinder or lozenge or block shaped. There may be three or five wires sticking out. Of the types with 3 wires, the middle one (differing colour, like transparant insulation hose) is supposed to be connected to the motor's stator iron and the remaining two (both black, sometimes one blue and one brown) are to be screwed underneath the same switch terminals as those wheere the motor's terminal leads are connected to. The types with 5 wires have two wires sticking out at one end and three at the other. This build type is solely there for the manufacturer's convenience, since they are in fact "through-feed" types. The two wires are connected to the double pole switch and the three wires are connected to stator iron and the two motor terminals. But as a capacitor, the contents are the same as in a 3-wire type.

As for choosing the right voltage and construction; be sure the cap can at least handle 250 Volts AC (or sine wave sign). If only DC is mentioned (single or double horizontal line), the value must at least be 630 Volts. Conventional suppressor caps have insulation layers of wax impregnated paper of polyproylene film. Especially the wax types are known to explode with relish, because the wax vaporises (=expands) so easily. The best caps for this purpose are polyester film types. This special film has certain "self-healing" properties by melting shut tiny flash-over holes, before they can progress into larger scale short-circuit spots. These caps are known as "MKT" types.

The Vishay line is an excellent hint, i order there myself. The brand itself is of little consequence, there is also no point in going through the expense and trouble to get hold of the original part, which is not an MKT cap anyway. I have a tray at the ready, filled with a range of different value MKT caps. For any tool with a failed cap, i start with a closely matching X-component and test the result with a portable FM radio. If the result is good, i don't even bother about the Y-component. But if there is still some disturbance, i do add the Y caps. Values between 1000 and 4700 pF (picoFarad) are widely available in many types (MKT and MP polypropylene). I make sure their DC rating is 1000 Volts ( 400V AC), to consider the specific Y-component's shock hazard.

I'll try to find some pics of some of my own Frankenstein capacitor tinkerings, which have all worked fine for years and years. But i must find back the tools i put them in first, and open them up for pics. And that may take a bit of time.

To round it off, i underwrite the admin's warning: if not experienced or in doubt, have this job done for you by a qualified person. However, don't let them pull the wool over your eyes; not a hugely expensive 100% original spare part is necessary, only a specific cap value and a high enough voltage rating is needed, preferably of an MKT type.

Meanwhile, good luck and greetings from Holland!

Gerhard