Magnum L / N / H

Common issues

• Impeller wear or erosion from abrasive solids in the drainage water
• Mechanical seal failure allowing water ingress into the motor housing
• Cable entry/gland seal degradation causing water ingress and an earth leakage or thermal trip
• Overheating or thermal trip from dry running or a blocked inlet strainer
• Bearing wear from continuous submerged duty
• Float switch or level control malfunction causing dry running or overfill of the sump

Inspection checklist

• Check the seal chamber oil for water contamination - milky oil is an early seal-failure warning
• Test motor winding insulation resistance
• Inspect the impeller and wear plate for erosion and running clearance
• Check the power/control cable and gland for damage or signs of water ingress
• Verify float switch or level control operation
• Check the inlet strainer/screen for blockage
• Test thermal protection and earth leakage trip function
• Inspect the lifting handle/chain and any guard for integrity before each deployment

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Mechanical seal kit (upper and lower)
• Impeller and wear plate/ring set
• O-ring and gasket kit
• Cable entry seal kit
• Bearing set

Safety

• Correct earthing and a passed insulation resistance test are required before each submersion
• Use only the rated lifting point/chain - never lift or lower by the power cable
• Confined space precautions may apply when working in the drainage pit or bilge itself
• Entanglement hazard at the open impeller during maintenance when the pump is out of the water

Class survey

Where used within a class-required bilge or drainage arrangement, function testing (start/stop, alarm response, and where practical a capacity check) is typically required at surveys; portable emergency drainage pumps may need a periodic capacity demonstration.