On Sep 28, 2011, at 7:15 AM, Artem Evdokimov wrote:
Are you indeed referring to the oil-filled high voltage transformer core in
the older model generators?
Yes.
(Newer ones tend to use solid state voltage multipliers).
That sounds much more sane.
I recall that there were issues with those things that were
eventually traced to elevated humidity. Now, that was humidity around 80%
which should not be the case for most systems these days since most of us
seem to prefer humidity controlled environments (for the sake of the
cryostreams) but it might be worth checking some local leaks etc.
Well, I'm at DIY-U, so this very likely is a potential source of the problem.
We have to supply our own hamsters for the electrical generators, too.
One more reason that the tank transformer might go bad would be inadequate
matching between power input and drain, especially high-drain situation
caused by an undetected high current (like a parasite current too weak to
cause arcing, but strong enough to damage transformer over time). Did
your/Rigaku's engineer check the voltages and currents in the tube tower? Do
you have the option to record currents while no one is attending the
instrument (in the even that the problem is intermittent)?
I don't think anything like that was ever done, but I am not sure. We shipped
it back
to them, and they need more money to continue diagnosis, so we are probably
just going to cut our losses on this decade-long nightmare.
Artem
On Tue, Sep 27, 2011 at 8:51 AM, Patrick Loll pat.l...@drexel.edu wrote:
Bill,
What do you mean by high voltage tank? When I hear this term, I think of
the oil- (and PCB-) filled tank housing the transformer on an old generator;
but there's nothing like that on the R-Axis. Do you mean the blue box
housing the detector controller? If so, then I can tell you that we've had
ours plugged into a 1000 VA UPS (APC Back UPS Pro) for 10 years, with never
a glitch (and I'm told that Philly power is not pretty).
If instead you're referring to the high voltage tank on the generator, then
I have no idea of what to do (although replacing the power cable doesn't
sound like a bad idea)...you'd probably need to steal an entire 7-11 to pay
for a UPS large enough to condition power for that.
Pat
On 26 Sep 2011, at 10:15 PM, William G. Scott wrote:
Hi Citizens:
We seem to run through high voltage tanks on our Raxis IV like guano goes
through a goose. Has anyone else had this problem, and, more importantly,
what is the best way to protect them. I am assuming it might have something
to do with our electrical supply, which is a bit unreliable.
Also, does anyone have an extra used functional one they want to get rid
of? We've run out of 7-11s to rob to pay for this, and our friendly and
helpful radiation safety staff think the best way to deal with this problem
is to hack apart the power cable, so it is a current (so to speak) source of
frustration.
Thanks in advance.
Bill
William G. Scott
Professor
Department of Chemistry and Biochemistry
and The Center for the Molecular Biology of RNA
228 Sinsheimer Laboratories
University of California at Santa Cruz
Santa Cruz, California 95064
USA
William G. Scott
Contact info:
http://chemistry.ucsc.edu/~wgscott/
