Sorvall RT/T6000D - Page 112

SORVALL®
Centrifuges
6-11.
Time
Control
(refer
to figure
6-9)
System
Descriptions:
Electrical
The timer
control knob
has settings
from
0
to
30
minutes (35 minutes
for
50
Hz
centrifuges)
and
the
oo
setting
for
indefinite
run time
(HOLD
setting on
RT/T6000
and
RT/T6000B
centrifuges.
SNs
9101800
and
below).
When
the
timer
control
knob is
turned to
a setting
other
than OFF,
the door solenoid
de-energizes,
latching
the
door.
In
addition.
+12 Vdc
passes
through one set
of
timer switches
to
the
speed
control
and
energizes
it,
allowing
current
to
flow to the
motor
(if the
speed
control
knob
is
set
to
a
position
other than
zero
or
OFF.
In
the timed
mode (0 to
30
minutes)
the drive
motor runs
for
the
set amount
of
time and
shuts
off
automatically
when the
set
time
elapses.
In
the
°°
mode,
drive
motor
runs
continuously
until the timer
or
speed
control
knob
is
turned to
the
OFF
position.
In
the timed
mode
only,
a
second set
of
switches on
the timer
assembly closes
and
passes
115
Vac to
the
timer
motor
assembly,
causing
it
to
begin
rotating.
Once
the
timer
motor
reaches
zero.
a
cam on
the
timer
assembly
opens
both
+
12Vdc
and
115
Vac switches
and
removes
power
to
the
motor
control
circuit
and
the
timer motor
assembly.
Turning
the time
control
knob
to
zero or
OFF
during
a
run
terminates
it
immediately.
To
Speed
Control
Switch
SW6
From
T1-1
POUJOF
Transformer
From
T1-2
ruwoi
Transformer
P/J18-
//
\N
AC
ACC
5
7
1
Timer
Assy
c
I
N"
C
NO
—\\—
0.02
p,F
-^ft-
Q
2
————^
From
P/J8-12
+12 Vdc
Figure
6-9. Timer
Control
Circuit
6-13