The compressor or the drive motor is blocked
Make sure the drive motor is disconnected
from the power supply
Remove the fan cover
Try to turn the drive motor with the
compressor by hand
If the unit is still frozen: remove the drive mo-
tor and check the drive motor and the
compressor separately
If the compressor is blocked:
Repair the compressor (Busch service)
The drive motor is defective
Replace the drive motor (Busch service)
The compressor is blocked
Solid foreign matter has entered the
compressor
Repair the compressor (Busch service)
Make sure the suction line is equipped with a
screen
If necessary additionally provide a filter
Corrosion in the compressor from remaining
condensate
Repair the compressor (Busch service)
Check the process
Observe the chapter Conveying Condensable
Vapours (
Ú
page 7)
The compressor was run in the wrong direc-
tion
Repair the compressor (Busch service)
When connecting the compressor make sure
the compressor will run in the correct direction
(
Ú
page 5: Installation)
The drive motor is running, but the
compressor stands still
The coupling between the drive motor and
the compressor is defective
Replace the coupling element
The compressor 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
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
Tighten or replace loose connections
The compressor runs in the wrong direction
Verification and rectification
Ú
page 4: Instal-
lation and Commissioning
Foreign objects in the compressor
Stuck bearings
Repair the compressor (Busch service)
The compressor runs very noisily
Defective bearings
Repair the compressor (Busch service)
Worn coupling element
Replace the coupling element
Low oil level in the synchronising gear
The synchronising gear is leaky
Repair the compressor (Busch service)
Synchronising gear damaged due to operation
with low oil level
Repair the compressor (Busch service)
The compressor runs very hot
Insufficient air ventilation
Make sure that the cooling of the compressor
is not impeded by dust/dirt
Clean the fan cowlings, the fan wheels, the
ventilation grilles and the cooling fins
Install the compressor in a narrow space only
if sufficient ventilation is ensured
Ambient temperature too high
Observe the permitted ambient temperatures
Temperature of the inlet gas too high
Observe the permitted temperatures for the
inlet gas
Insufficient gas transfer
Provide a pressure relief valve
Mains frequency or voltage outside tolerance
range
Provide a more stable power supply
Troubleshooting
MI 1502 BP
page 10
0870152627 / 101117
