Micropump GN Series Installation, Operation and Warranty Information - Manual (Page 17)

17
DOC No: 7046 REV G
Decoupling is an inherent feature of magnetic couplings and DOES
NOT indicate a pump failure. Decoupling should only occur when the magnet
decoupling torque has been exceeded. Decoupling can be a safety feature,
preventing inadvertent pump/motor overloads.
Magnet Decoupling
How to Recognize Magnet Decoupling
Magnet decoupling occurs when the load on the pump exceeds the coupling torque
between the magnets. The magnets are forced out of pole-to-pole alignment and are
decoupled. When decoupling occurs, the driving magnet speed increases to motor no-
load speed while the driven magnet and pumping parts remain motionless.
Causes of Magnet Decoupling
Due to the quiet operation of magnetic pumps it is not always possible to detect, without
disassembly of the pump, when the magnet coupling and pumping parts are operating
incorrectly. It is therefore important to be able to recognize possible causes of magnet
decoupling:
• Blockage or restriction in the discharge side of the system
• Discharge pressure exceeds decouple point
• Fluid viscosity too high
• Foreign particles jamming pumping parts
• Binding or stuck pumping parts - this may occur between pumping cycles as a result
of dried residue of the fluid being pumped. Drain and flush the pump to remove the
residue. Refer to the Maintenance section for instruction on draining.
Magnet Recoupling
Before recoupling ensure that the cause of the decoupling has been identified and
rectified. To recouple the magnets the motor must be stopped, allowing the magnets to
re-align, and then restarted.
NOTE