Honeywell MN7505A Actuator Failures.

[lwarren]

Has anyone had high failure rates with the MN7505A actuators?

[digo]

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.

[lwarren]

I have them failing after they have been in awhile. We are not manually moving them.

[kirkH]

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.

[craftyringwiseveteran]

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.

[MDaly]

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.

[lwarren]

I didnt think I was the only one having problems with these.

[simux]

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.

[orion242]

Ditto on repositioning every few seconds.

Then again I bleed orange and IMHO HW actuators are power hungry boat anchors.