42
BÜCHI
Vacuum Controller
V-800/V-805
13 Maintenance
Malfunction
Possible cause
Remedy
No display
No current to apparatus
Turn mains switch on
Check mains connections
Frequent switching of valve or pump
System is untight
Control all sealing points (tubes and
their connections)
Hysteresis is too small
Choose larger hysteresis (if end
vacuum is greater than 700 mbar, set
to automatic hysteresis)
Valve does not switch
Valve does not close
Valve coil is dirty
Valve cable is not plugged in
No vacuum
Tubing incorrec
See Chapter 4, Installation
Incorrectly cabled
See 5.1 Controls
Vacuum is not reached
Back evaporation Rotavapor
Empty receiving flask
Water pressure to water jet pump is
Completely open water tap
too low
Auto distillation has ”abated”
Manually decrease pressure until the distillation starts again, then, if so desired,
return to the automatic function.
Distillation has ended
a) Back evaporation from the receiving flask is too strong (especially
despite not dried out completely
solvent mixtures), drain receiving flask and start distillation again
b) Malfunction in distillation procedure is not exactly defined (for example,
sudden cooling, heat flow is too low, etc.). Decrease pressure manually until
the distillation starts again, then return to automatic function (V-805)
Rest moisture is too high after
Control to end dryness by manually decreasing pressure of product
auto distillation
13.6 Troubleshooting
