LP
E4
2
01
8.
01
e
n-
G
B
, I
D
-N
o.
: 1
63
-0
41
/0
www.imo.se
10
Problem
Cause
What to do
Pressure too low
- The pressure relief valve is set too
low.
- Counter pressure in the discharge
line is too low due to a major leak-
age.
- The valve piston is stuck in open
position.
- Something is restricting the flow in
the suction line. (This would usually
cause noise).
- The pumped liquid contains a
significant amount of compressible
gas, such as free air. (This would
usually cause noise).
- A too small pump has been chosen.
Readjust the pressure relief valve.
Check the components in the discharge
line inclusive the recipients.
Check the valve. See Maintenance and
Service instruction for this pump.
Check all components in the suction
line (strainers, valves etc.).
Contact your IMO AB representative.
Pressure too high
- 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.
Readjust the pressure relief valve.
Reduce the pressure setting until oper-
ational temperature has been reached.
Check the discharge line.
Drive motor difficult to
start or tends to stop by
tripping the motor over-
load relay
- Counter pressure too high.
- Liquid too cold.
- Motor is undersized for the prevail-
ing conditions.
- Electrical power supply faulty.
- Motor overload relay set too low or
is faulty.
- Incorrect setting of Y/D starter.
See above: Pressure too high.
Readjust the pressure relief valve to a
lower value. Thus the power consump-
tion for the pumping is relieved and
overloading due to the high viscosity
may be avoided. When the liquid has
reached normal 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.
Noise and vibration
22
Monitor the
pump function
and shut down
if any sign of
malfunction is
noticed
- The flow to the pump is insufficient.
- Insufficient support of pipe work.
- Air leakage into the suction line.
- Faulty electrical supply.
See chapter: The flow is too low.
Check for pipe vibrations in the pump
connections. Check that the pipes are
sufficiently clamped.
Check the suction line for air leakage.
Check all three phases of the supply.
