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Rob Spiegel
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Blogger
Re: Quick reuse
Rob Spiegel   4/24/2012 11:36:32 AM
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Good point, Jmiller. It sounds like he was taking a window fan and using it as an adict fan. Certainly a fan mounted in the attic. Certainly you wouldn't need three speeds for a fan way up in the attic.

jmiller
User Rank
Platinum
Re: Quick reuse
jmiller   4/23/2012 8:12:13 PM
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As is often the case, sometimes it is not the design that is flawed but the incorrect part being used for something it may not have been designed for.

Rob Spiegel
User Rank
Blogger
Re: Quick reuse
Rob Spiegel   4/13/2012 4:22:52 PM
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Yes, Jmiller, I was wondering about that as well. For the type of use that was intended, a variable speed fan was not required. Nor is a pull cord.

rcwithlime
User Rank
Silver
Not the 1st time that has happened
rcwithlime   4/10/2012 11:35:24 AM
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I have seen this same thing happen several times with Pedistal fans. (having had to replace the switches, if the motor did not burn up) (Pedistal fans are the larger fans more for industrial use, that stand about 6' tall, or like you see in many exercise places to move the air around.)

I have seen it suck up the cords when someone attaches a light string onto the chain, it sucks in the string and then the chain. Normally, the fan has a wire surround guard that the blocks the chain from going into the fan. Air flow is insufficient to lift up the chain and suck it between the wire mesh, but add on a light string and there you go. I even had someone add on the string, had this happen, removed the string afterwards and stated it was never there. He had just thrown the string in the nearby trash can, and when I looked, there it was.

I have also seen this happen when the fan was placed into a Boxed-in frame. This helped to create more air flow immediately around the motor housing (which the chain come out of) and sucked in the chain.

And then there are those who do not test what they sell, as others have advised. Seems everywhere you turn, you find something that could have been made more user friendly with only minor changes.
But with mass produced off shores junk being imported, actual testing is very limited. And any part that is heavier add a fraction of a cent to cost...

jmiller
User Rank
Platinum
Re: Quick reuse
jmiller   3/31/2012 4:45:01 PM
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Kind of sounds like this may have been a product that was not exactly used in the exact application it was designed for.

jmiller
User Rank
Platinum
Re: Fan switches on the fritz
jmiller   3/31/2012 4:41:03 PM
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In my experience one of the biggest failures of engineers is not going down to the lab and putting there hands on the finished product.  In so many companies you write some kind of test request and someone else does the test.  Engineers should be right in there helping with or definitely monitoring any test results.

Another failure of young engineers is to not understand how their components or systems affect the next guy down the line. 

Further, how many times do companies actually take the time to do a good design review and/or design failure mode analysis.

jmiller
User Rank
Platinum
Re: Fan switches on the fritz
jmiller   3/31/2012 4:33:29 PM
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I think this may also be an example of the failures that can occur without proper project management.  Sometimes the system just isn't set up to allow someone to take into account how everything goes together.  It seems like we bog our project managers down with so many presentations to upper management and cost analysis and other non-productive stuff that they don't have time to do simple design reviews.  Kind of sad.  Good example of what not to do, though.

jmiller
User Rank
Platinum
Re: Fan switches on the fritz
jmiller   3/31/2012 4:28:26 PM
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Interesting that it appears the entire ceiling fan market has issues.  I wonder at what price point does the american market place start to pay more for higher quality.  Will we pay more for a higher quality toothbrush.  probably.  Will we pay more for a higher quality car, absolutely.  But when it comes to that $50-$125 price range it appears we will pay for what we get and not complain.  Until we start to vote with our dollars and communicate to businesses that we will pay for qualiy, we are doomed to stay where we are.

Rob Spiegel
User Rank
Blogger
Re: 3-speed fan motor control
Rob Spiegel   3/29/2012 10:36:06 AM
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Seems like a problem like the amount of weight on the fan pull cord is a hard thing for a company to miss. It's certainly not a matter of cutting corners. I guess it must be a matter of just not thinking.

OLD_CURMUDGEON
User Rank
Platinum
More on room ceiling fans ....
OLD_CURMUDGEON   3/29/2012 8:19:48 AM
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All the ceiling fans in our house, some dating more than 20 years have split phase motors.  And, to the best of my recollection all of them were manufactured either in Taiwan or mainland China, so I'm NOT talking American-made HUNTER or CASABLANCA (now defunct!) units.  Yet, when I inspect the chamber where the direction switches & speed control swithes are housed, I see there is a multipole capacitor with the approx. values of 2 uf, 5 uf & 8 uf.  So, one would assume that these are switched into the winding to provide the additional phase shift to change the fan motor's rotational speed.

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