29
4 Troubleshooting Guide
Fault
Pump does not
start.
Pump does not
reach ultimate
pressure.
Pumping speed is
too low.
Pump gets
unusually hot.
Pump is too loud
Oil consumption
is too high, oil
mist at exhaust.
Oil in the intake
line or vacuum
vessel.
Oil is turbid or
dark
Possible cause
Pump is connected incorrectly.
Operating voltage does not match motor.
Motor protection switch incorrectly set (on three-phase motors)
Switch is malfunctioning (on single-phase motors)
Motor is malfunctioning.
Oil temperature is below 12°C (54°F).
Oil is too viscous.
Exhaust filter / exhaust line is clogged.
Vane is broken. (Sign : pump is jammed).
Pump is seized up. (Sign : pump is jammed).
Pump is too small
Measuring technique or gauge is unsuitable.
Pump is too cold
Float valve does not close
Inadequate lubrification due to
- missing oil,
- contaminated oil,
- clogged oil lines.
External leak
2)
Anti-suckback valve close
Exhaust valve is incorrectly mounted or malfunctioning
Vanes are stuck in their slots
Rotor clearance is too large
Dirt trap in the intake port is clogged.
Exhaust filter is clogged.
Connecting lines are too narrow or too long.
Anti-suckback valve is hard to open.
Vanes are stuck in their slots
Cooling faces are obstructed or dirty.
Inadequate lubrification due to
- low oil level,
- contaminated oil,
- clogged oil lines.
Exhaust valve is malfunctioning.
On new pump : indadequate run-in of vanes
Inadequate lubrification due to
- low oil level,
- contaminated oil,
- clogged oil lines.
Pump is too cold
Fan is worn out
Motor cover is not properly tightened
Large vacuum leak in system
Exhaust filter elements are clogged or damaged
Nozzle of the float valve is clogged.
Oil level is too high
Exhaust filter element is incorrectly mounted
Oil comes from vacuum system
Anti-suckback valve is obstructed
Sealing surfaces of the anti-suckback valve are dirty or damaged
Motor turns in the wrong direction (on three-phase motors)
Oil level is too high
Condensation
Oxidation
Remedy
Connect correctly.
Replace the motor.
Set motor protection switch properly.
Replace the switch
Replace the motor.
Heat the pump and pump oil or use different oil.
Change the oil.
Replace the filter or repair the pressure relief valves,
clean the exhaust line.
Replace the vane
Repair the pump.
Check the process date; replace the pump, if necessary.
Use correct measuring technique and gauge. Disconnect the pump
from the system and measure the pressure directly at the pump
Let the pump warm up for approx. 15 min.
Check the float valve and repair it if necessary
Refill oil
Degas or change the oil
Clean the oil lines and oil case
Repair the pump
Repair the valve
Mount the valve properly or replace
Remove the vanes ; clean the vanes and slots
Repair the pump
Clean he dirt trap; Precaution : install a dust filter in intake line
Replace the filter element
Use wider or shorter connecting lines
Remove the vanes ; clean the vanes and slots
Repair the pump
Set pump up correctly or clean the cooling faces
Refill oil
Degas or change the oil
Clean the oil lines and oil case
Replace the valve
Noise must disappear after approx. 300 hours of
operation, otherwise consult our Service Dpt.
Refill oil
Degas or change the oil
Clean the oil lines and oil case
Let the pump run up for approx. 15 min
Change the fan
Tighten the motor cover
Repair vacuum leak
Replace the exhaust filter.
Check the float valve, clean the nozzle
Drain the exces oil
Dismount the filter element and tighten the filter support
Check the vacuum system
Clean or repair the valve
Clean or repair the intake port and anti-suckback valve
Interchange two phases at the motor connection
Drain the excess oil
Degas the oil or change the oil and clean the pump.
Precaution : open the gas ballast valve or insert a
condensate trap
Change the oil
Reference
section
1)
2.3
Service
2.3
3.8
Service
3.3
3.4 / 3.6
3.7
Service
-
2.7
2.5
3.6
3.3
3.2.2 / 3.3
-
Service
3.6
3.6
3.7
Service
2.2.1 / 3.5
3.4
2.2
3.7
Service
2.1
3.4 / 3.6
3.3
3.2.2 / 3.3
-
3.6
3.3
3.2.2 / 3.3
-
2.5
Service
2.3.2
3.4
3.6
3.3
3.4
-
3.6
3.6
2.3
3.3
3.2.2 / 3.3 / 2.2.1
1) Reference section : This column refers to the section in the Operating Instructions that contains the applicable repair information.
2) Bubble test : Let the pump run at operating temperature with degassed oil, without gas ballast and with closed intake port.
Immerse the exhaust line in a bucket of water. If a steady stream of bubbles appear, the pump has an external leak.
N.B. : For any other operation as descr bed before, return the pump to a LEYBOLD service center.
