The ra dial clea rance bet ween the ro tor (o) and
the cy lin der is no lon ger ade quate
Read just the va cuum pump (Busch ser vice)
Inter nal parts worn or da ma ged
Re pair the va cuum pump (Busch ser vice)
The oil re turn line starts in an area ven ted to at mos phe ric pres sure. Par ti cu lar ly on small mo del
pumps, a fair ly large amount of air is suc ked through the oil re turn line, which may pre vent the
ul ti mate pres sure from rea ching 20 bar abs.
In or der to ex clude this pos sible cause:
squirt oil through the gas dis charge/pres sure connec tion (b) into the oil re turn line. While oil is
being suc ked in, the ul ti mate pres sure is not af fec ted by the air nor mal ly suc ked through the oil
re turn line.
The gas conveyed by the va cuum pump
smells dis plea sing
Pro cess com po nents eva po ra ting un der va -
cuum
Rea di ly vo la tile and thus ga seous com po nents
of the oil, e.g. ad di ti ves, par ti cu lar ly right af ter
an oil change.
NOTE
: This is no in di ca tion of a mal func tion
of the oil se pa ra tor. The oil se pa ra tor is able
to re tain dro plets of oil, ho we ver no ga seous
com po nents of it
Check the pro cess, if ap pli cable
Use a dif fe rent type of oil, if ap pli cable
The va cuum pump does not start
The drive mo tor is not sup plied with the cor -
rect vol tage or is over loa ded
Sup ply the drive mo tor with the cor rect vol -
tage
The drive mo tor star ter over load pro tec tion is
too small or trip le vel is too low
Com pare the trip le vel of the drive mo tor star -
ter over load pro tec tion with the data on the
na me plate
Cor rect if ne ces sa ry
In case of high am bient tem pe ra ture:
Set the trip le vel of the drive mo tor star ter
over load pro tec tion 5 per cent above the no -
mi nal drive mo tor current
One of the fu ses has blown
Check the fu ses
The connec tion cable is too small or too long
cau sing a vol tage drop at the va cuum pump
Use suf fi cien tly di men sio ned cable
The va cuum pump or the drive mo tor is bloc -
ked
Make sure the drive mo tor is dis con nec ted
from the po wer sup ply
Re move the fan co ver
Try to turn the fan by hand
If the unit va cuum pump/drive mo tor is still
fro zen:
Re move the drive mo tor and check the drive
mo tor and the va cuum pump se pa ra te ly
If the va cuum pump is bloc ked:
Re pair the va cuum pump (Busch ser vice)
The drive mo tor is de fec tive
Re place the drive mo tor (Busch ser vice)
The va cuum pump is bloc ked
So lid fo reign mat ter has en te red the va cuum
pump
Re pair the va cuum pump (Busch ser vice)
Make sure the suc tion line is equip ped with a
mesh screen
If ne ces sa ry ad di tio nal ly pro vide a filter
Cor ro sion in the va cuum pump from re mai -
ning conden sate
Re pair the va cuum pump (Busch ser vice)
Check the pro cess
Observe the chap ter “Instal la tion and Com -
mis sio ning, Ope ra ting No tes, Con veying Con -
den sable Vapours”
The va cuum pump was run in the wrong di -
rec tion
Re pair the va cuum pump (Busch ser vice)
When connec ting the va cuum pump make
sure the va cuum pump will run in the cor rect
di rec tion (see “Instal la tion”)
Troubleshooting
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