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What to do
Disturbance
Cause
Pressure too high
Drive motor difficult to start
or tends to stop by tripping
the motor overload relay
Noise and vibrations
!
Monitor the pump
function and shut
down if any sign
of mal function is
noticed.
- The pressure relief valve is set
too high.
- The oil is too cold (or
has higher viscosity than
anticipated).
- Counter pressure in the
discharge line is too high.
- Counter pressure too high.
- Liquid too cold
- Motor is undersized for the
prevailing conditions.
- Electrical power supply faulty.
- Motor overload relay set too
low or is faulty.
- Incorrect setting of Y/D starter.
- The flow to the pump is
insufficient.
- Insufficient support of pipe
work.
- Bad alignment
- Air leakage into the suction
line.
- Free air in the liquid or gas
cavitation.
- Faulty electrical supply.
Readjust the pressure relief
valve.
Reduce the pressure setting
until operational temperature
has been reached.
Check the discharge line.
See above: Pressure too high.
Readjust the pressure relief
valve to a lower value. Thus
the power con sumption for
the pumping is re lieved and
overloading due to the high
viscosity may be avoided.
When the liquid has reached
nor mal temperature and thus
flows easily, the relief valve is
reset to normal pressure.
Check the motor.
Check the motor and motor
connection.
Readjust or replace the relay.
Readjust the setting of the
starting sequence. The time
before the motor overload
relay is tripped should not
exceed 10-15 seconds.
See chapter: The flow is too
low.
Check for pipe vibrations in
the pump connections. Check
that the pipes are sufficiently
clamped.
Check alignment, see page 4.
Check the suction line for air
leakage.
For pumps with Tuning:
Adjust the Tuning. If this does
not help or for pumps without
Tuning: Contact your IMO
representative or IMO service
dept.
Check all three phases of the
supply.
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