No announcement yet.

Airco 300 timer issue

  • Filter
  • Time
  • Show
Clear All
new posts

  • Airco 300 timer issue

    My airco 300 (Miller 330 A/BP) has developed a problem. Sometimes the little electro-mechanical timer, used to keep cooling gas flowing after current is shut off, fails, leaving the gas running.

    There's a small (about 1/2" diameter) pair of disks in the top of the timer unit. They're connected to a gear. When the machine is running, the disks are pushed apart, there's a small gap between them. When I shut off the current, the gap closes up, and the timer counts down, eventually shutting off the gas. I'm pretty sure the disks make a clutch.

    What's happening is that sometimes when I shut off the current, the disks don't close up. A couple of times, I've heard a sort of faint grinding noise, and observed the gear jumping around, as if it was almost engaging with another gear further down inside the timer.

    When it does malfunction, if I turn off the unit, and turn it back on, the disks close up, and the timer counts down perfectly.

    My inclination is to take it apart and carefully clean everything. Is that a bad idea? Any words of caution there? Also, should any of that stuff be lubricated? I don't really want to spray oil around in there. Maybe some graphite?

    Here's some pix, one of the timer with the disks closed, and the other with them open.

    Any advice welcome.
    Attached Files