Absolute beginner requesting help identifying component

[tebbybabes]

Hello, my name is Steven and I've just come across your forum. Took the chance to register so I might get the chance to further my knowledge. 

Quick backstory is I have a ceiling fan that is slower than molasses and I at least know enough that it's most likely a capacitor problem.  The fan company says that the problem is an easy fix and that I just need to replace the controller module and it will be right as rain.  Trouble is, the electronic module, while user replaceable, is also $100, while the fan itself is just $200.  I figured I would try to have a look at it and maybe learn something new. 

Which takes me to my current query.

I was hoping I could ask help in identifying this particular component in the photo.  It's the one that looks like dumbells?  I know the big yellow ones are capacitors and I thought they would be the one needing the replacing, but these ones look a bit dogdy.

Thanks in advance and if I'm barking up the wrong tree, apologies.

[xrunner]

They are inductors with a heat shrink over the windings. Usually labelled with an "L" such as you see on the PCB.

[Ian.M]

.... and they look absolutely normal, with no signs of overheating or other issues.

[tebbybabes]

Thanks heaps, folks.  That was even faster than I was hoping! 

and @xrunner, I have now noticed the "L" that you mentioned. Thanks.

In this case, I will now see if I can learn how to test capacitors to find out which one needs replacing.  Can't say that I'm super confident as the last time I soldered circuits was 30 years ago and I remember I did a piss-poor job of it. 

[andy3055]

In the ceiling fan there should be another capacitor at the top, inside the canopy. That could be the most likely faulty part.

[Siwastaja]

And those yellow capacitors are likely OK, too. Swapping parts randomly tends to end up costly.

Indeed, if there is a "run" capacitor at the motor, it's a more probable cause, because it can run hot next to the motor.

[tebbybabes]

Thanks for the replies and the very helpful input. 

The only reason I thought it might be one of these things was because the tech support person on the line sounded extremely confident that replacing this module was the definitive fix. It led me to believe that any "run" capacitor would be in it.  I have another photo of it that some of you folks might find more representative.  This "control module" is located up top in the canopy.  It was conveniently happened to be a user replaceable part.

Anyway, I was initially planning to remove the caps one by one and check them with a multimeter to determine which one needed replacing?

[taydin]

You can only measure the capacitance value of a known working capacitor when using a multimeter. But there are two types of faults that will cause little or not change in the capacitance, but still will prevent the cap from working properly:

High ESR: The capacitance value might be measure a little off, so it will look fine, but the cap will not be able to do its job. Standard multimeters lack ESR measurement. You need an LCR meter to measure ESR.

Insulation breakdown at operating voltage: This is a rare problem, but when it happens, the capacitor will measure fine even with an LCR meter. But when normal operating voltage is applied to it, its insulation breaks down partially or completely and the capacitor won't do its job at all. The only way to properly test the cap is to apply rated voltage and observe leakage current (not easy, especially when voltages are high and typical leakage is low).

It is much easier and cheaper to just replace caps that are likely to fail.

[andy3055]

By the way, taking another look at the last picture you posted, I wonder if that one capacitor sitting alone to the left is the run capacitor I was referring to. If there is no other capacitor lying alone inside the canopy, there is a good chance they mounted it on this board. Usually they are in the order of 2uF or so. The other 3 caps must be for speed control and this one cap is acting as the run cap. Just a thought.

[Gregg]

Also check the electrolytic caps like C2, C13 and the other two similar ones. In a hot environment like a ceiling fan, they can degrade and cause the control circuitry to malfunction. These usually show some sign of leaking or bulging, but not always.
The oval yellow caps are not likely a problem, but anything can happen.

[Jwillis]

BRT2-SS-212D PCB relays 12 Vdc 8 A   

The three caps with inductors are LC tank circuits . They oscillate at different frequencies for different motor speeds. The motor is likely a Shaded-pole synchronous motor.Change the frequency change the speed of the motor. The triacs switch between each tank circuit.
The Relay may be for forward reverse difficult to tell without a board schematic or picture of the traces. Their as a chip on board .What is it.

[ArthurDent]

You've got some good information here. I'm also assuming this is a remote control 3-speed fan which accounts for 3 identical inductor/triac/capacitor circuits on the board like the one I circled. I'd guess that the single big yellow cap is the run cap as previously stated and that is the problem. The capacitance has probably decreased greatly and all speeds are very slow. Checking the value should verify this if it is the problem.

[tebbybabes]

You can only measure the capacitance value of a known working capacitor when using a multimeter. But there are two types of faults that will cause little or not change in the capacitance, but still will prevent the cap from working properly:

High ESR: The capacitance value might be measure a little off, so it will look fine, but the cap will not be able to do its job. Standard multimeters lack ESR measurement. You need an LCR meter to measure ESR.

Insulation breakdown at operating voltage: This is a rare problem, but when it happens, the capacitor will measure fine even with an LCR meter. But when normal operating voltage is applied to it, its insulation breaks down partially or completely and the capacitor won't do its job at all. The only way to properly test the cap is to apply rated voltage and observe leakage current (not easy, especially when voltages are high and typical leakage is low).

It is much easier and cheaper to just replace caps that are likely to fail.

Thank you for taking the time to explain so much.  I am obviously way way over my head, but am more than willing to listen. I like how the last bit is quite practical from an expediency standpoint!

By the way, taking another look at the last picture you posted, I wonder if that one capacitor sitting alone to the left is the run capacitor I was referring to. If there is no other capacitor lying alone inside the canopy, there is a good chance they mounted it on this board. Usually they are in the order of 2uF or so. The other 3 caps must be for speed control and this one cap is acting as the run cap. Just a thought.

Thanks. You and @ArthurDent are thinking along the same lines. I don't yet know what spec is the lone cap but I can read enough of the other three to say that they are 2.0uF, 1.0mfd, 2.5uF

BRT2-SS-212D PCB relays 12 Vdc 8 A   

The three caps with inductors are LC tank circuits . They oscillate at different frequencies for different motor speeds. The motor is likely a Shaded-pole synchronous motor.Change the frequency change the speed of the motor. The triacs switch between each tank circuit.
The Relay may be for forward reverse difficult to tell without a board schematic or picture of the traces. Their as a chip on board .What is it.

I'll take as good a picture as I can, but can say that it has LNK302PN printed on it.

You've got some good information here. I'm also assuming this is a remote control 3-speed fan which accounts for 3 identical inductor/triac/capacitor circuits on the board like the one I circled. I'd guess that the single big yellow cap is the run cap as previously stated and that is the problem. The capacitance has probably decreased greatly and all speeds are very slow. Checking the value should verify this if it is the problem.

Product documentation states that it is a 7 speed remote controlled ceiling fan. And yes, all speeds are slow as molasses in winter.
As soon as get my ducks in a row and remove that big lone cap, I will report in.

[ArthurDent]

When I posted I was thinking of each of the three circuits used separately but with 3 circuits you can have 3! (3 factorial) or 3x2x1 combinations (plus all circuits off) to get 7 combinations so what you say about it being a 7 speed fan makes sense. The triacs are just used as switches to switch all the combinations of the 3 circuits on or off. Below is a photo of a similar circuit board I found on line that does about the same thing. They used SCRs instead of triacs but the effect is the same. You can see that the capacitors are in about the same ratio as on your circuit board and the difference might be they used SCRs instead of triacs.

The IC on the board with some of the other small parts form a really neat AC-DC buck converter and is probably used to get 12VDC for the relay coil and perhaps other parts of the controller.

[amyk]

Product documentation states that it is a 7 speed remote controlled ceiling fan. And yes, all speeds are slow as molasses in winter.

Are you sure it's not the bearings that need oiling?

[andy3055]

I don't think it is the bearing. That can be easily checked though. If you just spin the fan without power, it should spin for a few revolutions. If not, then one could suspect the bearing.

The big cap should have the ratings on the bottom that is towards the board. Just de-solder one side and see what is underneath.

[tebbybabes]

Below is a photo of a similar circuit board I found on line that does about the same thing. They used SCRs instead of triacs but the effect is the same. You can see that the capacitors are in about the same ratio as on your circuit board and the difference might be they used SCRs instead of triacs.

Thanks for the photo.  I will admit, the first time I read your reply, I missed it.  

@amyk

In this case I can definitely report that it isn't the bearings because the damn thing spins very very freely.

@andy3055

Will do, as soon as I get to the non-holiday period and I'm no longer running around like a chicken.   Happy and Blessed holidays everyone!

[tebbybabes]

Assumed "run" capacitor removed.  Have not been able to properly test yet because it turns out I don't have a multimeter with capacitance. 

Now hunting around where to order this part.

I've got an advance question, how do I determine polarity for the replacement cap? I took a photo of how it's oriented on the original parts but have failed to find any identifying marks.


And finally an aside, I think my el cheapo solder sucker wasn't working very well... It took ages to remove enough solder to finally disengage the cap and even when I did, there was still heaps of solder left.  Do I need to hunt for a wick instead to get it cleaned up better?

[Zero999]

Those yellow capacitors are non-polarised, which means they can be connected either way round.

You can try desolder wick and extra flux might also help.

[tebbybabes]

Those yellow capacitors are non-polarised, which means they can be connected either way round.

You can try desolder wick and extra flux might also help.

Much obliged.

Will hunt around for the wick and the capacitor then.

[andy3055]

Did you also check inside the canopy if there is another cap? If not, try changing the cap that you lifted.

[tebbybabes]

Did you also check inside the canopy if there is another cap? If not, try changing the cap that you lifted.

Thanks. Confirmed that there are no other capacitors, or electronics for that matter, in the canopy.

[tebbybabes]

I've come up against a snag.  After hunting around my local area, it appears that sourcing caps like these are harder than I thought.  I also went online and didn't find many options. I often found the same specs listed under "motor start/run motor" categories, however they were always shaped like the rectangular plastic boxes.  They're very reasonably priced too.

The only ones that appeared to have a similar shape to the one I lifted are caps that have been described as either "audio"  or "snubber" and their pricing is several orders of magnitude higher. I have an impression that these specialised caps aren't actually what I need, but decided to ask for advice.

Finally, my google-fu must be lacking, but can anyone point me in the direction of where best to source this sort of thing in Oz? Doesn't matter if online or in meatspace.

Thanks again.

[Jwillis]

I've come up against a snag.  After hunting around my local area, it appears that sourcing caps like these are harder than I thought.  I also went online and didn't find many options. I often found the same specs listed under "motor start/run motor" categories, however they were always shaped like the rectangular plastic boxes.  They're very reasonably priced too.

The only ones that appeared to have a similar shape to the one I lifted are caps that have been described as either "audio"  or "snubber" and their pricing is several orders of magnitude higher. I have an impression that these specialised caps aren't actually what I need, but decided to ask for advice.

Finally, my google-fu must be lacking, but can anyone point me in the direction of where best to source this sort of thing in Oz? Doesn't matter if online or in meatspace.

Thanks again.

CBB20 Motor Run Capacitor axial lead  ?uF 

[tebbybabes]

Axial Polyester/Polypropylene Film capacitors  would be your best bet for this application .These would have the broadest range of capacitance and voltage rating .As long as the capacitance and voltage rating are correct you should be alright . Depending on manufacturer ,the structure may be different . That doesn't matter as long as it fits the circuit board. Can you acquire the values for the capacitor you need?

It says 1.5uf 800VDC ± 10%.  From what I can gather, I would just need to sorta extend the legs on the rectangular housed cap that I found.  They seem to have a bit shorter total length that the spot on the PCB.