convert 115v 50hz to 120v 60hz

Discussion in 'General Electronics Chat' started by softbrix, Sep 18, 2013.

  1. softbrix

    Thread Starter New Member

    Sep 18, 2013
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    I purchased 2 lift-master 1355m garage door opener, I was told my a few local installers that they are not working because something in the newer openers detect 50hz instead of 60hz and will not work to prevent damage to the motor. Is it possible to bypass this? or convert the 50hz to 60hz?. I thought about using a AC->DC->AC converter but I dont think i can get enough wattage to make both garage doors work.
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Even if it were possible would it be wise? Presumably the motor design is such that it will overheat if run at 50Hz.
     
  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Have you gone through all the troubleshooting steps starting on page 33 of the manual?
    Can't believe they would sell something in an area that wasn't compatible with local mains.
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I believe he is going the other way, 50 to 60Hz? If so it should be OK, the problem MAY come in if the motor mechanism has rpm sensor, many do.
    Although may be OK as the motor will run slightly faster on 60Hz, if standard 1ph split phase motor.
    Max.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Agreed.
    Looking at the manual it is identical to the Sears line, and they are made in Tuscon Arizona, so I don't see them being 50Hz only, for some reason?
    Max.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    First what country are you in and what is your mains voltage/frequency?
    Then what is the specified voltage/frequency of the garage door opener.. (120V 60HZ more than likely unless purchased outside of the US)
     
  7. softbrix

    Thread Starter New Member

    Sep 18, 2013
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    They do have rpm sensors, they are built for 60hz, but locally we use 50hz. I wonder if I could change the rpm sensor to a older sensor that's not so sensitive.
     
  8. #12

    Expert

    Nov 30, 2010
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    Better to change the door opener to fit the local power lines.
     
  9. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Or just buy a proper garage door opener?

    Running a 60hz motor on 50hz will do the following.
    It will turn 20% slower.
    Cooling will drop dramatically.
    The load's horsepower requirements will drop, possibly dramatically.
    V/f will increase possibly causing a large increase in current draw.
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    You could always rig it temporarily to test, the heating effect should not come in to it as Garage door openers are made to operate at very short time intervals, Not as though it is going to be running hours on end!
    Max.
     
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