Version with three-phase motor:
The vacuum pump was run in the wrong di-
rection
Repair the vacuum pump (Busch service)
When connecting the vacuum pump make
sure the vacuum pump will run in the correct
direction (
Ú
page 6: Installation)
After shutting down the vacuum pump the
vacuum system exerted underpressure onto
the pump chamber which sucked back exces-
sive oil from the oil separator into the pump
chamber
When the vacuum pump was restarted too
much oil was enclosed between the vanes
Oil could not be compressed and thus broke a
vane
Repair the vacuum pump (Busch service)
Make sure the vacuum system will not exert
underpressure onto the shut-down vacuum
pump, if necessary provide an additional
shut-off valve or non-return valve
After shutting down the vacuum pump con-
densate ran into the pump chamber
When the vacuum pump was restarted too
much condensate was enclosed between the
vanes
Condensate could not be compressed and
thus broke a vane
Repair the vacuum pump (Busch service)
Make sure no condensate will enter the
vacuum pump, if necessary provide a drip leg
and a drain cock
Drain condensate regularly
The drive motor is running, but the vacuum
pump stands still
The coupling between the drive motor and
the vacuum pump is defective
Replace the coupling element
The vacuum pump starts, but labours or runs
noisily or rattles
The drive motor draws a too high current
(compare with initial value after commission-
ing)
Loose connection(s) in the drive motor termi-
nal box
Version with three-phase-motor:
Not all drive motor coils are properly con-
nected
The drive motor operates on two phases only
Check the proper connection of the wires
against the connection diagram
(particularly on motors with six coils)
Tighten or replace loose connections
Version with three-phase motor:
The vacuum pump runs in the wrong direction
Verification and rectification
Ú
page 5: Instal-
lation and Commissioning
Standstill over several weeks or months
Let the vacuum pump run warm with inlet
closed
Oil viscosity is too high for the ambient tem-
perature
Use synthetic oil, if necessary use oil of the
next lower viscosity class (CAUTION: opera-
tion with too low viscosity can cause chatter
marks inside the cylinder)
Warm up the oil with a heater prior to starting
up the vacuum pump, or run the vacuum
pump in intervals in order not to let it get too
cold
Improper oil quantity, unsuitable oil type
Use the proper quantity of one of the recom-
mended oils
(
Ú
page 18: Oil cha
nge:
Ú
page 9: Mainte-
nance)
No oil change over extended period of time
Perform oil change incl. flushing
(
Ú
page 9: Maintenance)
The exhaust filter is clogged and appears black
from burnt oil
Flush the vacuum pump
Replace the exhaust filter
Fill in new oil
(
Ú
page 9: Maintenance)
In case the oil life is too short: use oil with
better heat resistance (
Ú
p
age 18: Oil
) or ret-
rofit cooling
Foreign objects in the vacuum pump
Broken vanes
Stuck bearings
Repair the vacuum pump (Busch service)
The vacuum pump runs very noisily
Defective bearings
Repair the vacuum pump (Busch service)
15
