Dear All,
We have a pair of Quantum Designs ATL-160 helium liquefiers that are refrigerated
using air cooled Sumitomo FA-70 compressors. The FA-70 units are new, having
been replaced last June (both show a D.O.M. of May2025). A few weeks back one
of the ATL cold heads came to a screeching (literally) halt and the problem
was that the FA-70 indoor unit had blown fuse FU-7 (LfT 1.25AL 250VP). The next
week the same unit died overnight. I found the same fuse blown. Monday it did
the same thing for me in person and then Tuesday morning I found both my liquefiers
down, each having blown the same fuse overnight. My cold heads are not old, or
dirty, and have been liquefying well. I’ve checked the power being
supplied, helium supply pressure, etc. Our building manager relayed a story of
a batch of compressors used on Thermo -80’s freezers being bad and is
wondering if this might be a similar case. Is there anyone else out there with
newer FA-70’s that is having a similar problem?
Thanks,
John
John Grimes | NMR Facility Manager
Complex Carbohydrate Research Center, University of Georgia
315 Riverbend Road
Athens, GA 30602-4712
(706) 542-4483
jgrimesjr_at_uga.edu ( jgrimesjr_at_uga.edu )
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Received on Wed Nov 12 2025 - 06:57:38 MST