Grundfos CM 3-10

Visual inspection: leakage quantity 1-10 ml/24h is normal. If >20% water content in oil chamber after 1 week of operation, seal is defective. Seal faces NOT to be touched with bare fingers. At standstill: inject silicone oil between pump housing and coupling to prevent face adhesion.

Check circulation lubrication: relubricate SKF LGHP2 grease using grease gun. Measure bearing clearance with caliper per workshop guidelines. After 100,000 operating hours perform replacement. Motors up to 11 kW are permanently lubricated (no relubrication required). Abnormal vibrations/noise indicate bearing wear.

Visual inspection for: erosion, pitting, cavitation damage, cracks, dents or irregularities on impeller blade leading edges and hub. Inspect wear rings (front/rear) for scratches/deformation. Measure clearance between impeller and pump housing with caliper. Decrease in flow rate/pressure build-up/current consumption indicates impeller damage.

Motor to be inspected visually and cleaned regularly for adequate cooling. In dusty environments inspect more frequently. Monitor temperature (elevated heat development = early fault signal). Detect bearing wear through vibrations/noise. Compare current consumption vs. rated value. Motor bearings in 2/4/6-pole motors up to 11 kW are maintenance-free lubricated; larger motors to be lubricated regularly.

Check oil level after 1 week of operation (after seal replacement). Monitor water content: >20% water means seal failure. Oil change every 3,000 operating hours or 1x/year (Shell Ondina 917 or similar). Inspect oil colour, odour, turbidity for contamination/combustion products.

For seawater/marine environments: pump must be designed in high-grade stainless steel (EN 1.4517 Duplex, AISI 316) or titanium. Perform visual inspection for surface rust, pittings, discoloration. High-grade stainless steel designs (EN 1.4408) for T>40°C and chemical fluids. Use special seals (Super Duplex) and sealants for aggressive media.