What control strategy uses 24vac and has three wires; one common, 0-24vac on one line to drive cw and 24-0 vac to drive ccw? This is in a Lennox VVHC system and I'm trying to replace the damper actuators. It seems like Belimo LMB24-3 ought to work, but it doesn't because it's not really floating point control. sometimes there's 24 vac on one input line, sometimes it's on the other and sometimes there's 12 vac on each.
Thanks for the help.