Pquest is up.

Len Booth booth at snf.stanford.edu
Wed Oct 11 14:50:52 PDT 2000


Pquest users -
        I've restarted the turbo pump.  When Matt
was running the system, for some unknown reason the
turbo pump controller sensed an overcurrent condition
(ie. - the controller sensed that the pump motor was
drawing way too much current, trying to keep the
pump rotor turning at the speed setting of 600Hz)
so the controller went into a "self-protect" mode,
and turned the pump off.
        The most common reason for this to happen
is when there is too much gas dumped into the
etch chamber (overloading the pump) or a large
leak into the etch chamber (again, overloading
the pump).  Matt said he did not see anything like
this happen while he was processing.
        Let's just run it and see if it repeats.
                        Len



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