Dear colleagues,
here at TUM we are in the fortunate situation that we are currently building a new NMR center,
which will upon completion house all (well, most) of our high-field NMR machines, as well as
biochemistry labs and offices. However, the question of backup power for that building is still open.
In the old department building (where the pumped 750 MHz and 900 MHz magnets are housed), there is a
campus-wide emergency net which is normally connected to the power grid, like the normal power network.
When grid power fails, it is separated from the grid and a couple of Diesel generators are supposed to
jump in within > 1 min (actually it will take longer, since the departments have to be switched over to
the emergency grid oneby one, to avoid overload). In the past there were a few problems (Diesels not starting,
switching problems) which have been adressed and hopefully fixed in the meantime.
For our new building, we were told that a connection to the emergency grid is not possible, since its capacity
is almost exhausted and it will therefore be limited to cases where human lifes are endangered by power failures.
Our pumped magnets and (in the near future) also a 1.2 MHz AEON magnet with pumps AND helium recycler do not
qualify ...
As a compromise, we will get a big UPS that could support several magnet pumps plus 2-3 deep temp. freezers
(in the biochemistry labs) for up to 4 hrs.
In the past power failures were usually short (split-second up to few minutes), although a remember one or
two blackouts that lasted 1-2 hrs. (involving major damage to critical transformers / switches that could not
be repaired or bypassed immediately). With nuclear / coal fired power plants being phased out and replaced by
natural sources (or electricity imports ...), the future stability and reliability of the general power grid
is at least open to discussion.
We are a bit worried about the small, but non-zero chance that a power failure might last longer than 1-2 hrs.,
the UPS runs empty and the vacuum pumps will stop. I don't know exactly how long a 950 MHz or 1.2 GHz magnet
can survive without vacuum pumps before it quenches, but I am not keen to find out.
So my question is (finally!):
- if you have sensititive equipment like pumped magnets operating at 2 K, deep temperature devices etc.
that will not just stop, but get seriously damaged upon a longer power outage
- what kind of backup do you have? UPS, generators, ...? For how long can they take over?
who is operating them (you? your institute / department? the university / company?)
Thanks in advance,
Gerd
--
PD Dr. Gerd Gemmecker
Bayerisches NMR-Zentrum
Dept. Chemie, TU München
Lichtenbergstr. 4
D-85747 Garching
Germany
Raum/Room 32 109
Tel. +49 (89) 289-13308
Fax +49 (89) 289-13869
e-mail: Gerd.Gemmecker_at_ch.tum.de
Internet: http://www.gemmecker.de
Received on Tue Nov 24 2015 - 07:26:39 MST