Controls, Indicators, and Displays
SORVALL
®
Centrifuges
3-18
Terminal Conditions
Terminal Condition messages alert the user to a serious fault condi-
tion. Runs are disallowed or terminated. These conditions typically
cannot be remedied by the user; the centrifuge should be removed
from service until it is repaired by Thermo Service.
Alternate Tach Failure
During a run, the primary tachometer signal was indicating
2000 rpm or more while the secondary tachometer signal
was indicating 0 rpm. Wait for the rotor to stop spinning (this
could take as long as 30 minutes), then use the mechanical
override to remove all sample from the rotor, unplug the
centrifuge and contact Thermo Service. Read the WARN-
ING. (WatchLog Network™ record: TACH FAULT.)
AIR TEMP SENSOR FAILURE
The chamber air temperature sensor indicated either an open
circuit, or a temperature above 45°C. The fault indicates a
sensor failure or a refrigeration system problem. After the
rotor stops and the chamber door is opened, note if the
chamber is warm – if so, the rotor may be too hot to touch.
Unplug the centrifuge and contact Thermo Service. (WatchLog
Network™ record: AIR SENSOR.)
COMPRESSOR FAILURE
While the refrigeration compressor was working to cool, the
chamber air temperature sensor detected an increase of 10°C
or more from when the compressor first turned on. The fault
indicates a refrigeration system problem. After the rotor
stops and the chamber door is opened, note if the chamber is
warm – if so, the rotor may be too hot to touch. Unplug the
centrifuge and contact Thermo Service. (WatchLog Net-
work™ record: COMPRESSOR.)
COMPRESSOR SOLENOID FAILURE
While the refrigeration compressor was working to heat, the
chamber air temperature sensor detected a decrease of 10°C
or more from when the compressor first turned on. The fault
indicates a refrigeration solenoid/valve problem. Unplug the
centrifuge and contact Thermo Service. (WatchLog Net-
work™ record: COMP. SOLENOID.)
!
W A R N I N G
Do not open the chamber
door when the rotor is spinning.
In the event of a tachometer failure
(or any failure where RUN speed does
not register), the brake will not operate
and the rotor will coast to a stop –
from high speed, deceleration to 0
could take as long as 30 minutes.
Before using the mechanical override
to open the chamber door, use the
viewing port in the door to make sure
that the rotor has stopped spinning.
Opening a chamber door when a rotor
is spinning exposes hazardous
energy; contact with a spinning rotor
could cause personal injury.
To Next Page