Hi All,

Trying to ascertain why a DC MinkaAire fan (84") will no longer change speeds, or in some cases even start itself in the lowest setting speed.

I have replaced the receiver/controller on the fan (U shaped PCB), but the new one did not resolve the issue.

I can get the fan to run consistently on Speed 1, but only after spinning it a bit by hand. And, sometimes I can get it to run on 2 or 3, occasionally on 6, even (not often). Most times shifting from 1 to 2-6 is only met with repetitive clunking as it spins down, but in all cases as long as I don't let it stop, it will return to Speed 1.

MinkaAire, true to their reputation, tossed out "it's the receiver," but would assist no further except saying "go buy a new fan."

It's only three years old - a beautiful piece of work - but, silly to just throw away.

Thoughts of options - and, or how to troubleshoot? (there isn't much to troubleshoot since it is brushless, right?)

Thanks!

 

Welcome to the forums.

I doubt it's the motor. Typical brushless DC motors are 3 phase and are controlled directly from the control board. That would mean three wires to the motor. No replaceable capacitors.

What's the number on the control board ?

 

Hi Pete,

Yeah - that's what I thought - it's all in the pcb, unless some motor wiring issue ... can't find much on repairing DC motor ceiling fans :-)

The model number of the pcb is DL01051000 ... looks same as the one that was in it. (photo)

I would probably pull the whole thing and evaluate on a bench, but the ceiling is at 16', so I just swapped out between blades and when it made no difference, I put the old one back in.

Thanks!

 

Here's the actual board - looks pretty high quality.

 

It looks like CON3 (3 pin) is the motor connection location.
There is a variable motor driver under that finned heatsink.

Unfortunately I thought I knew someone that could assist but that didn't pan out.
I can't find any useful troubleshooting information on that board.

 

No problem, Pete.

BTW, during my unsuccessful attempt to work with MinkaAire customer service (misnomer), they told me the blade assembly needed to be on to see if the motor would respond to the new controller ... to count blades to assess each speed by rpm, but would this matter to simply see if the controller would work?

Plugging in controller and testing without reinstalling seven foot wide blade assembly on tall ladder is easier 😂

 

Ran it at speed 6 ... sounds like motor is spinning to faster speed, but almost like there is a slipping clutch or stripped gears ...

 

I'm fairly certain that is a direct drive 3 phase DC motor.
Running with the blades on makes sense as the motor is pulsed and the blades supply momentum.

 

Well, sure, but wouldn't running without the blade assembly allow at least determination of the basic speeds?

 

As the motor windings are pulsed the force of the spinning rotor causes a cumulative effect like with a flywheel. Without that spinning mass the motor steps and doesn't increase in speed smoothly. It's hard to explain. The video below explains it in technical detail.

DC motor control video

 

OK - not sure my conversions to .gif will work, but here are two videos - the first is normal operation at speed 1 which I can always get, but sometimes need to spin the blade a bit.

The second is of the fan after I select speed 6 - it sounds like part of the motor is accelerating, but the blade is not ...

 

I see the pictures but there is no audio. I tried to download to convert but I get errors.
Typically videos are posted at you tube and linked here.

 

Learning how you convert to youtube ... see if this works, please?

https://www.youtube.com/watch?v=1cbYsEUVtw4

 

Finally found a YouTube video with same manufacturer and clunking/grinding sound ... almost identical! https://www.youtube.com/watch?v=upIjwnvjeHg

Their solution was a new fan from manufacturer - another fellow noted he had same problem.

 

Your video is set to private so I can't see it.

I have never heard a fan make a sound like that.
That's not even a bearing sound.
I see what you mean about the fan blades not matching the same speed that motor appears to be running at. It almost looks like the fan is loose on the shaft.

 

Hi PJ - stumbled on a write up on Amazon for same fan ... sounds like exactly the same problem.

"This is a great fan, quiet, nice looking, easy to operate, but it only lasted about a year. We were able to take it apart and found that the magnets inside are only glued to the housing. At first it started to make a really loud sound on speed 6, then over a couple weeks it started being loud on speed 5, 4, 3, 2, 1, and then stopped working completely. We were able to screw a very tiny screw thru the housing into the magnets on each side to hold it in place. Now it works beautiful again. Not sure why the manufacturer thought glue was a good idea. Should be a 5 star fan but from my research on the internet, sounds like lots of people have the same problem after about a year. If your not mechanical and don't want to fix this problem, get a different fan."

I can't figure out how to contact the folks who posted, but this sounds plausible, especially given the many videos from Indian fellows who are repairing by re attaching the magnets on DC fans with epoxy ...

I think the stator magnets - they could be individually glue in but more likely imbedded in an alloy ring with the ring being glued to the outside of the housing. What do you think? Based on the sound, the other videos and this single solution (I can't contact the person since was in an amazon review) this does not sound like a receiver controller problem.

 

Here's an Indian video with fellow gluing the permanent magnets (?) back into place ...
https://www.youtube.com/watch?v=Gt30ko5gGy4

Another video showed the magnets being embedded in a metallic ring, and in that one they epoxied the whole ring into place.

 

Something for you to follow.I wouldn't be servicing that fan.
My go to brand has always been Hunter.

 

So, PJ, you wouldn't fix an $800 ceiling fan?

 

So, here's two different owners - thus sounds like them fixing a faulty Minka Aire crappy design.

 

Isn't it amazing... a company knows there's a design problem and doesn't fix it.

 

Pulled blade assembly and pulled up cover, again - took some photos this time.

The motor attaches to the extension rod like most ceiling fans, has four Allen head bolt around the perimeter, and one large nut holding the motor (and the aluminum casting which holds the trim cover) onto the main stator shaft. There are no screws/bolts that go from top to bottom. The screws on the bottom hold the blade assembly to the rotor.

I removed the four Allen bolts - but did not remove the shaft nut. No play felt anywhere except where the assembly is pinned to the extension rod, and then friction locked by two screws.

The motor is taller than most of the BLDC fan motors seen being rebuilt by the Indian guys on YouTube. I am assuming this is to make it more powerful since the blades are so much longer and there are so many of them.

Recall one Amazon reviewer discussed putting screws through the fan housing to hold the permanent magnets? The motor housing itself is the rotor so ya can't hold it to tell if anything is moving, but the noise is definitely from the inside of the motor. If one were to drill through from the outside of the motor and place three small screws hopefully to grab the permanent magnet ring, where to do it? :-) (I hate this sort of experiment)

I am going to wait for the weather to moderate a bit, then borrow a big ladder to pull fan from the ceiling box - then disassemble. Should I be able to remove the end nut, then the four Allen bolts, then split the motor at the bottom? Should only be a single bearing on that end, right? This might gain access to the rotor magnets?