FAAC 740 hums instead of working

[tkalfaoglu]

Hello everyone. I am going crazy with the recent problem of my gate opener (a sliding gate) with FAAC 740.

When I left home the gate apparently did not close (I drove off, I was in a hurry), found it open coming home.
Upon examining, I found the 16AH fuse in the house that's protecting the FAAC had popped.
When I re-applied power, I found that the door would not close. But there was a noise, like a hum coming from the machine.

I opened it up, checked everything, found nothing wrong (cobwebs galore however). Cleaned it up, disassembled the gears, found everything perfect mechanically. Opened up the top of the motor, wirings looked good (nothing darkened), motor turned freely by hand when the gate was disangaged, and when engaged, I could move the gate by manually turning the motor. So nothing wrong mechanically.

Measured the voltage between COM and CLOSE or OPEN pins on the controller, 218v.

I can hear the relays clicking anyway.

I replaced the capacitor. I removed all connections and re-did them (there are physical magnetic limit sensors on the door, and a pair of infrared eyes to stop it from closing if anything is in between.)

Nothing helped. I made a video of its operation - or lack of:
https://kalfaoglu.com/tmp/VID_20210204_122942.mp4

Btw, Recently a few things happened, I don't know if any of them are related to this problem..

The blinking light stopped working
There were torrential rains in my area, but the inside of the motor seemed dry.
The motor is about 10 years old.

I am at a loss.. What else shall I try? This is so frustrating..

Many thanks!
-turgut

[RyanB]

Hi Turgut,

Have you re tested the voltage after the capacitor change? A humming motor with no movement usually relates to low voltage/bad capacitor or a low force issue. My concern is that you found the fuse protecting the automation to be popped. This does highlight that there could of been an issue electrically when the gate attempted to close which may have cause damage to the motor internally which is not allowing the motor to actually turn when it is engaged.