Results 1 to 9 of 9
  1. #1
    Join Date
    Jan 2002
    Location
    Fort Worth\Dallas, Texas
    Posts
    1,694

    Honeywell MN7505A Actuator Failures.

    Has anyone had high failure rates with the MN7505A actuators?
    Go Rangers!

  2. #2
    Join Date
    Apr 2007
    Location
    San Diego, CA
    Posts
    1,302
    When using declutch, return to minimum mechanical stop. Part of their new adaptation function, read up on 63-2633
    Also there's a service switch that should be set for at least 2 seconds prior, or something like that. We had one come back and our engineer figured it out via RTFM.

  3. #3
    Join Date
    Jan 2002
    Location
    Fort Worth\Dallas, Texas
    Posts
    1,694
    I have them failing after they have been in awhile. We are not manually moving them.
    Go Rangers!

  4. #4
    Join Date
    May 2009
    Location
    in the present
    Posts
    85
    I just tested one of these on the bench that I condemned in the field. Works on the bench, I think maybe the little selector switch wasn't quite lined up just right, not sure. I don't get a warm fuzzy though. This job I am on now is the first time we have used more than a couple at a time. Discovered that is is basically a floater that takes an analog signal. If you clutch it you better remember where it was because they don't go back to the commanded position without a power cycle. That stupid wiring plug is a PITA too, kinda tough to troubleshoot when you can't access the wiring. In short I hate them, this probably isn't any help to anyone but I feel a little better.

  5. #5
    How are you using them? 0-10 VDC, Floating, 2 Position? I have seen similar actuators that have failed becasue the control operating them caused them to reposition every few seconds.

  6. #6
    Join Date
    Dec 2007
    Posts
    90
    Yep we have had failures too. I have them stop driving after being installed for a few months(only to drive again normal after a power cycle), I have had them drive 10-0 no matter where the switch is positioned and I seen them push pass their stops and bind up.

  7. #7
    Join Date
    Jan 2002
    Location
    Fort Worth\Dallas, Texas
    Posts
    1,694
    I didnt think I was the only one having problems with these.
    Go Rangers!

  8. #8
    Join Date
    Sep 2006
    Location
    Alaska
    Posts
    456
    I've seen some electronic actuators that constantly move due to the controller constantly changing the output. Then the actuator burns up because it's moved constantly for months. Not sure if the controllers can have a deadband in them to help make them last longer.

  9. #9
    Join Date
    Jan 2003
    Location
    USA
    Posts
    1,560
    Ditto on repositioning every few seconds.

    Then again I bleed orange and IMHO HW actuators are power hungry boat anchors.
    Propagating the formula. http://www.noagendashow.com/

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