Troubleshooting
72
WBV.PU.002.EN VX136QD V2.0
Possible cause
Possible remedy
Observe notices and
safety notes
Chapter
K
Faulty electrical connection
Check electrical equipment.
"Drive"
Error in the hydraulic system
Check the hydraulics.
L
Motor speed too low during
variable frequency drive
operation
Install external fan, increase motor speed.
"System control":
Variable frequency drive
operation
M
Stiff running caused by
swollen lobe elastomer
Check the medium resistance of the lobe
elastomer.
"Specifications":
Material description for
rotary lobes
Stiff running caused by
accumulation of solid matter
in the gaps
Clean pump chamber; increase the gaps
Chapter
"Reducing the starting torque"; adjust the
drive.
"Repair", "Drive"
N
Oil level in the gearbox is not
OK
Chapter
"Gearbox"
"Maintenance"
O
Operation-related
fluctuations in buffer
chamber
Chapter
"Buffer chamber"
"Maintenance"
P
Mechanical seal damage
Change the mechanical seal,
Chapter
"Cartridge mechanical seal change"
"Repair"
Faulty repair of the
mechanical seal
Buffer fluid tank leaking
Check buffer fluid tank for leaks.
"Maintenance"
Q
Seal leaking
Chapter
"Dry buffer chamber"
"Maintenance"
R
Differential pressure too high
Reduce differential pressure.
"Specifications"
S
Medium viscosity above the
nominal value
Reduce speed. Increase medium temperature.
"Intended use"
T
Medium viscosity below the
nominal value
Increase speed, decrease medium temperature,
replace wear parts.
"Repair"
Gaps too large
Reduce gaps
Chapter
"Reducing the starting
torque" but with the procedure reversed
"Maintenance"
U
Medium temperature above
the nominal value
Reduce medium temperature.
"Intended use",
"Specifications":
Material description for
rotary lobes
V
Medium temperature below
the nominal value
Increase medium temperature (after consulting
Vogelsang).
W
Mechanical seal elements
not in the best position
Pressurise the buffer chamber once with the max.
permissible buffer chamber pressure (tank
pressure) (single mechanical seal: 5 bar,
double mechanical seal: 10 bar).
Then restore the design pressure.
"Buffer chamber"
"Pressurisable buffer fluid
tank"
Put the buffer chamber into operation in its non-
pressurised state (buffer fluid tank closed) and
observe the buffer chamber fluid level and
pressure.
Adjust the tank pressure (buffer chamber pressure)
to be higher than its design pressure. Observe
max. permissible buffer chamber pressure (tank
pressure):
Single mechanical seal: 5 bar,
double mechanical seal: 10 bar