Sorvall RT/T6000D - Page 156

SORVALL®
Centrifuges
RT6000
and
T6000
Centrifuges
5.
Locate
Zl
on
the
Motor Controls
P. C.
Board
and
install
an
1C
test
clip (dip
clip).
Connect
the
frequency
meter
lead
to
pin
13ofZl
(other
lead
to
ground).
6.
Plug
in
the
centrifuge
power
cord,
and
set
the POWER
switch
to
ON.
Increase
rotor
speed
to
1000
rpm.
Turn
brake switch
off.
7.
Turn timer
off
(pin
13
should
be
low).
8.
Adjust potentiometer
(R42)
so
that
pin
13
goes
high
at
200
rpm
+50
rpm/-
0
rpm
when
breaking. Repeat
if
necessary.
9.
Set the
POWER switch
to
OFF
and
unplug
the
centrifuge
power
cord.
10.
Disconnect
the
frequency meter,
then
plug
in the
centrifuge
power
cord.
11.
Calibrate
the imbalance detector
(see
paragraph
below).
g.
Imbalance Detector
Calibration
Be
sure
to note the following
points
when
calibrating the
imbalance circuit:
•
Before
starting
the calibration
procedure,
note the threshold level
value
on
the
field
service
report.
After the
calibration
process
is
complete,
also
note the final
threshold
value.
•
The threshold
adjustment must
fall
between
+0.5
Vdc
and
+4.0
Vdc
as measured
at
I.C.
Zl
pin
6.
•
Always adjust
the variable resistor
(potentiometer,
R
18) first.
If
you
reach the
+4.0
vdc potentiometer
limit
and
the
rotor
still
does
not
trip,
decrease
the
gap
by
turning
the
setscrew
1/8
turn
clockwise for
increased
sensitivity.
If
you
reach
the
+0.5
vdc
potentiometer
limit
and
the
rotor
continues to
trip.
Increase
the
gap
by
turning
the
setscrew
1/8 turn
counter
clockwise
for decreased
sensitivity.
•
You
can
decrease
the
imbalance sensitivity
by
decreasing
the
voltage
level
at
the
threshold test
point
measured at
I.C.
Zl
pin
6.
•
The
foam
insert and rubber
boot
affect the
sensitivity
of the
imbalance calibration;
make
sure they
are
installed.
•
The
rotor must
slow
to
100
rpm
or
below before the
next
run
is started.
•
If
the
calibration
produces
"passing"
results,
but
trips during
deceleration, the
calibration
needs
to be
continued.
The
rotor
should
not
trip on
deceleration.
1.
For centrifuges
with
serial number
8601094
and
above,
make sure
that
the set
screw
is
properly
positioned above the imbalance
detector. Use
a
feeler
guage
to
adjustthe set screw
so
thatthereisa
1.1
mm+0.13/-0.0 (0.045
inch+.005/-0.000)
gap
between
the bottom of the
set screw
and
the
imbalance detector
(see
page
5-38).
Rev.
7/93
7-27