23 September, 2014

TYC Synchronous AC Motor Teardown

I recently ordered a couple of TYC branded geared synchronous motors, from an online seller based in China.

The plan was to see if they would be suitable for use in repairing Breezair dump valve assemblies.  It turns out that they are somewhat suitable, but really far from perfect for the application and the quality isn't great.

Long story short, I modified the motors that were shipped to me and tested them out.  At first, no problems.  One of the motors was too weak (not enough torque) and the other was looking good until the output shaft came out.

The shaft wasn't held in by anything at all.  It appears that it's just pressed 2.8mm into a hole in a plastic gear, as you can see in the images below.

While modifying the shaft was the cause of the failure, it prompted me to open one of these motors up and check out how it was made.  So, here are the teardown photos for anyone who's interested:

Motor, after the output shaft was modified:

This wasn't supposed to happen...

The teardown begins.  Top cover removed.  As you can see, this motor uses plastic gears.  I expected it would and as such I tried not to heat up the motor shaft too much when I was modifying it.  It appears though I wasn't careful enough.

Close-up of the gear assembly.  The large white gear is the one that the output shaft was pressed into.:

Gears removed.  You can now see the actual motor:

Metal plate removed:

Motor Stator (electromagnetic coil).  Under the tape there are two knots, one in each of the blue wires, to stop you pulling them out of the motor.  Under the tape is just a coil of magnet wire:

Motor Rotor (the bit that spins/rotates):

The rotor has been removed, teardown complete:

All of the bits and pieces that made up the geared synchronous motor:

Motor specifications:

AC 12V
50/60Hz 4W
2.5 ~ 3R/MIN

Which basically means, its a high torque motor, moves very slowly (approx. 2.5 revolutions per minute), and can rotate counter-clockwise (CCW) or clockwise (CW).  This mode is also known as "free", I guess since the motor is free to turn in either direction when power is applied.  The direction can usually be influenced by applying a pressure to the output shaft in one direction or another.  The motor should then rotate in the direction that is easiest for it to move.

The motor in this teardown cost $8.40 AUD inc. shipping.

For comparison, below is a link to a better quality (mostly metal geared) synchronous AC motor:

All trademarks are the property of their respective owners.


  1. Thanks for sharing this great info. I have a similar problem of a Synchronous Motor from an old Christmas display. The specs for the TYC-40 match my motor exactly but my old motor has a long flat shaft. Any tips on gently removing the shafts to do a swap of the old shaft to the new TYC-40?

    1. I'd suggest you remove the front metal plate of the motor by bending back the four metal tags that hold the front plate on. Once you've done that the shaft and shaft gear will slide out of the bushing on the front of the metal plate.

      If both motors aren't the same TYC motor then there's no guarantee that you'll be able to swap the shafts.


  2. Hi Robert,

    Do you sell the motor suitable for the breezair?
    or point me in the right direction please, my drain pump is going up and down, and the mircoswitches are good.
    Not sure where to get a replacement motor from.


    1. Hi Duy,

      I don't sell the motors as the manufacturer wouldn't sell them to me when I wanted to order more of them.

      I can't point you in the direction of a good replacement. It's my personal experience that the cheap TYC ones on eBay don't work reliably in this application.

      Sorry I can't be of any assistance.


  3. A bloke sells a complete DRAIN valve restoration kit on eBay... just search for "breezair drain valve kit". Very good kit at a reasonable price.

  4. A bloke sells a complete DRAIN valve restoration kit on eBay... just search for "breezair drain valve kit". Very good kit at a reasonable price.

  5. Now that you can feel that there are some problems, it is best to call in the experts. Your best option would be to get in touch with the same shop from where you had purchased this air conditioner and get it repaired via them. heating repair fayetteville

  6. Look at the different frameworks before you settle on your choice.

  7. Thankyou for this wondrous post, I am glad I observed this website on yahoo. https://www.wtfixair.com.au/

  8. You need to discover a unit which is very energy proficient on the grounds that not exclusively will it set aside you cash over the long haul, it's better for the climate too. https://proaireq.com/air-duct-cleaning-equipment/

  9. Thanks for the blog post. Thanks Again. Awesome.ac repair rowlett

  10. On the off chance that you think you are a decent possibility for a dissipate cooler you can utilize the free AHAM apparatus referred to before to work out the legitimate size for your particular application as well. Sydney air conditioning services

  11. I value the blog post. Thanks Again. Awesome.HVAC Repair in Rowlett

  12. Looking forward to reading more. Great blog post. Really thank you! Want more.
    ac repair company in rowlett

  13. An evaporative cooler enjoys a great deal of upper hands over a standard air conditoner in light of the fact that it has a lower cost of establishment, requires less support and works with less energy. Since they are more uncommon in certain pieces of the country, it appears as though a many individuals don't have a clue how an evaporative cooler functions. hydronic heating system
    HVAC Services


When commenting, please make sure you tick the "Notify me" checkbox, otherwise you will not be notified when I reply to you!