Sorvall RT/T6000D - Rotor Imbalance Fault

SORVALL®Centrifuges
6-27.
Rotor Imbalance
Fault
(refer
to
figure
6-25)
System Descriptions:
Electrical
A
piezoelectric
crystal
is
used
to
provide
a
rotor
imbalance
signal.
The
imbalance
signal
is
created
when
physical
contact
is
made between
the
imbalance detector and
a
set screw
mounted
to
the
gyro-action
drive
(centrifuges
SN 8601094
and
below
were
manufactured
with the
imbalance
detector located
on
the motor mounting
plate).
There is
a 1.1 mm
(0.045
+0.005/-0.000 inch)
gap
set
between
the
set screw
and the
imbalance
detector to
ensure
a
run
condition at
19
grams
of imbalance and
a
fault
condition at
21
grams
of
imbalance
with
a
fully
loaded
H-1000B
rotor.
An imbalance
threshold
adjustment is
provided
on
the
Control
P.C.
Board to
adjust
for
these
levels.
A >1500
rpm
hardware
detector
disables
the imbalance circuit at
speeds
above
1500
rpm
to avoid
nuisance
tripping
due to
electrical
noise
from
the
motor.
Figure
6-25. Imbalance Circuit
Rev.
7/93
6-31