Beckman Couler ALLEGRA X-12/R, Service Manual, Page: 41 / 83

Section 3: Service Procedures
J. If voltage is within 2.5 +/- .1Volts DC after moving the rotor in both directions tie
down the bracket.
K. Perform a test run with a balanced rotor load and empty rotor. Monitor the 2.5 V DC
L. If the Voltage is within 2.5+/- .1V between a loaded or empty rotor the calibration is
complete.
M. If it isn’t within the tolerance perform steps E to L again.
Typically, 10-15 g should cause imbalance error I1.
3.2 Temperature
Control Systems
Warning: Unplug the centrifuge or turn off and lock out the main wall circuit
breaker before removing an instrument panel.
Warning: As long as the yellow LED on the Motor driver board is lit, the Bus
Voltage is still present. Wait until LED is off.
3.2.1 Refrigeration System Safety
Warning
: Refer to the safety notices in the front of this manual for cautionary notes
when working with refrigeration system. Read all brazing safety
notes. Always recover the refrigerant.
3.2.2 Refrigeration Functional Test
A. The SX4750 swinging bucket rotor is recommended for this test. Replace loaded buckets
with empty buckets. Temperature measurements are performed by using 40ml of
glycerol in two of the opposing buckets.
B. To precool the rotor and chamber, set temperature to -2
°
C, speed to 2000 RPM and time
for 30 minutes.
3-8 Allegra X-12/R, X-15R Service Manual 07/07