Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual page 166

UltiMate 3000 Series:
NCS-3500RS and NCP-3200RS
Message
Upper pressure limit
exceeded
Zero position not found
during the last revolution.
Zero position not found
during the last 3 revolutions.
Page 158
Remedial Action
NC pump
The message appears when the column pressure exceeds the set upper
pressure limit. In this case, the flow of the NC pump will be stopped.
Too high a column pressure may be caused not only by the column
itself but also by other components in the flow path of the NC pump
(depending on the application).
Loading pump
Check whether the flow path after the purge unit is blocked. To do so,
open the purge valve.
If the flow path is blocked:
- The trap column may be contaminated. Rinse or replace the
column.
- The autosampler may be blocked. Find and eliminate the source for
the blockage.
If the flow path is not blocked:
- Check the permeability of the filter frit in the inline filter. Replace
the filter frit if necessary (→ page 209).
- The switching valve in the column compartment may not have
switched properly. In this case, an additional message will appear
for the valve.
Turn the module off and on again by pressing the power switch on
the rear of the module. Contact Service if the message appears more
often.
Turn the module off and on again by pressing the power switch on
the rear of the module. Contact Service if the message appears more
often.
Operating Instructions