BUCHI Vacuum Controller V-855 - Manual (Page 46)

8 Troubleshooting
46 V-850/855 Operation Manual, Version E
8 Troubleshooting
This chapter helps to resume operation after a minor problem has occurred with the instrument. It lists
possible occurrences, their probable cause and suggests how to remedy the problem.
The troubleshooting table below lists possible malfunctions and errors of the instrument. The operator
is enabled to correct some of those problems or errors by him/herself. For this, appropriate corrective
measures are listed in the column “Corrective measure”.
The elimination of more complicated malfunctions or errors is usually performed by a BUCHI technical
engineer who has access to the official service manuals. In this case, please refer to your local BUCHI
customer service agent.
8 .1 Malfunctions and their remedy
Malfunction and their remedy
Malfunction Possible cause Corrective measure
No display Instrument has no current Switch instrument on, check mains
connectins
Frequent switching of valve or pump System is leaky
Hysteresis is too small Control all sealing points (tubes and
their connections)
Choose a larger hysteresis (if
the end-vacuum is higher than
700 mbar, set the instrument to
automatic hysteresis
Valve does not switch Valve does not close Valve coil is dirty
Valve cable is not plugged in
Valve is not adjusted, contact the
BUCHI customer service for assis-
tance
No vacuum Tubing or cabling incorrect Correct the tubing or cabling by
referring to the corresponding
chapters
Vacuum is not reached Back evaporation at the Rotavapor
Water pressure to water jet pump is
too low Empty the receiving flask and
completely open the water tap
Dry the pump diaphragm
Auto distillation has “abated” Manually decrease the pressure until the distillation starts again, then return
to the automatic function, if desired
EasyVac distillation “abated” Manually decrease the pressure until the distillation starts. The distillation
stops automatically
Distillation ended although not dried
out completely - Back evaporation from the receiving flask is too strong (especially for
solvent mixtures), drain receiving flask and restart the distillation
- Malfunction in distillation process is not exactly defined (e.g., sudden
cooling, heat flow is too low, etc. Decrease the pressure manually until the
distillation starts again, then return to the automatic function, if desired
Too much remaining liquid after auto
distillation Manually decrease the product pressure to distill the remaining liquid