15 Problems and their removal
Operating manual for micro annular gear pumps mzr-7240
Last update: March 2019
Technical data subject to change without prior notice!
67
15
Problems and their removal
Disturbance
Cause
Solution
1 The pump does not work.
No power supply
Check the power supply.
2 The pump does not pump the
liquid.
No liquid in the primary tank
Fill the recipient/tank with liquid.
Presence of air or gas in the pump
The pump cannot run dry against the system
pressure. Fill in the pump at no pressure or at
reduced system pressure.
Malfunction of the liquid supply
components (such as in the delivery tube,
the needle or external non-return valve)
Check the components for possible
disturbances to be eliminated. Cleanse the
accessories where needed.
Failure of the electric installation
Check the electric installation for the correct
cable configuration, loose contacts, etc.
The pump did not receive the start signal
or start conditions are not fulfilled.
Check if the start condition have been fulfilled
start signals (software control, PLC, start signal)
and the programs.
Motor disturbance: the red error LED is on. Check the failure condition of the motor
control with the Motion Manager software.
3
The pump does not start to
operate.
The pump does not take in the liquid.
The tubing on the induction side is too long or
has a too small internal diameter (a too low
NPSHA value).
The tubing or the fluid connection on the
induction (suction) side are not tight. Please
check the intake connection and the tubing.
Air bubbles in the fluid system
(tubes, valves, ...)
If the viscosity of the liquid is too high, apply
pressure on the suction side.
Check the pressure exerted on the primary
liquid tank.
An external non-return valve does not open.
Check the non-return valves.
Submit the non-return valve to a higher
pressure, so that the pump may fill in.
4 The motor turns, but the pump
does not operate.
No liquid in the pump
Fill the pump with liquid.
Air bubbles in the liquid supply system
(tubing, valves, ...)
Fill the pump and the liquid supply system with
liquid.
The non-return valve does not open.
Rinse the non-return valve.
Blocked delivery tubing or needle
Cleansing, flushing or exchange of the delivery
tubing or dosage needle
The coupling between the motor and the
pump is out of position.
Return the pump to the manufacturer.
The pump shaft is broken.
Return the pump to the manufacturer.
5 The pump is filled with liquid, but
does not pump it.
Error indicator (the red status LED on the
terminal box is on and the motor control
has set the error output).
Check the motor error status with the Motion
Manager software (command GFS). Try to
liberate the pump by making it operate for 1 s
in a reverse direction with -1000 rpm.
Adapt the motor current to the control.
Contact the manufacturer of the pump.
Presence of particles in the delivered liquid
or blockage of the pump.
Check the motor error status with the Motion
Manager software.
Try to liberate the pump by making it operate
for 1 s in a reverse direction with -1000 rpm.
Return the pump to the manufacturer for
cleansing. Use a filter, flush the liquid delivery
