CM, CME

Summary

Product identification

The Grundfos CM and CME pumps are non-self-priming, horizontal, multistage, end-suction centrifugal pumps of the close-coupled type. CM pumps feature mains-operated motors, while CME pumps incorporate an integrated frequency converter for continuously variable speed control. Both series use mechanical shaft seals.

Key Features:

• Compact design
• Modular construction for customized solutions
• High reliability with advanced shaft seal design
• Service-friendly with no special tools required
• Wide performance range
• Low noise level
• High-performance hydraulics
• Electro-coated cast-iron parts for optimized corrosion resistance

Materials in contact with pump media:

• Cast iron version (EN-GJL-200): Suction and discharge parts are cast iron. Impeller, chamber, and filling plugs are stainless steel (EN 1.4301/AISI 304). Gaskets between chambers are Tesnit® BA-U.
• Stainless steel versions: Available in EN 1.4301/AISI 304 or EN 1.4401/AISI 316.
• Pump shaft: Stainless steel (EN 1.4057/AISI 431) for cast iron versions, or EN 1.4301/AISI 304 or EN 1.4401/AISI 316 for stainless steel versions.

Shaft Seal Materials (O-ring type, fixed driver):

• Secondary seal: EPDM (ethylene propylene), FFKM (perflour), FKM (flour).
• Stationary seal face: Carbon (synthetic resin-impregnated), Silicon carbide (SiC).
• Rotating seal face: Silicon carbide (SiC), Aluminium oxide (Al₂O₃).
• Rubber parts (excluding neck ring and shaft seal): EPDM, FFKM, FKM.

Applications: The CM and CME pumps are designed for a wide variety of applications, including:

• Washing and cleaning (e.g., degreasing, CIP units)
• Water treatment (e.g., nano-, micro-, ultra-filtration, softening, demineralizing, desalination, distillation, booster pumps)
• Temperature control (e.g., electronic data processing, laser equipment, industrial refrigeration, heating/cooling in industrial processes, humidifying)
• Pressure boosting (e.g., drinking water, process-water systems)
• Dosing/mixing
• Chemical and pharmaceutical industries

Operating limits

Ambient Temperature:

• Maximum ambient temperature depends on liquid temperature:
  • Liquid temperature +90 °C: Maximum ambient temperature +55 °C
  • Liquid temperature +100 °C: Maximum ambient temperature +50 °C
  • Liquid temperature +110 °C: Maximum ambient temperature +45 °C
  • Liquid temperature +120 °C: Maximum ambient temperature +40 °C
• For CME pumps, the maximum ambient temperature is +40 °C, regardless of liquid temperature.
• Maximum permissible liquid temperature for CM-A and CME-A (cast iron) is +90 °C.
• Motor output (P2) must be reduced if ambient temperature exceeds +40 °C (CME) or +55 °C (CM), or if installed above 1000 metres above sea level.

Storage and Transport Temperature:

• CM pumps: -50 °C to +70 °C
• CME pumps: -30 °C to +60 °C

Installation:

• Must be installed on a plane surface and fixed.
• Air locks in pump housing and pipework must be avoided.
• Should be installed with easy access for inspection, maintenance, and service.
• Requires a well-ventilated location.

Maximum Operating Pressure and Permissible Liquid Temperature:

• At liquid temperatures below 0 °C, higher motor outputs may be needed due to increased viscosity (e.g., if glycol is added).
• The 120 °C limit applies only if the pump has an AQQE shaft seal.
• CM-I, -G and CME-I, -G pumps for liquid temperatures below -20 °C are available on request.

Liquid Temperature Range (O-ring material):

• EPDM: -20 °C to +120 °C
• FFKM: 0 °C to +120 °C
• FKM / liquids containing water: -20 °C to +90 °C
• FKM / oil without water: -20 °C to +120 °C

Environmental Rating:

• Three-phase CME motors: UL NEMA 3R environmental rating.
• Single-phase CME motors: Not tested against UL NEMA environmental rating.
• All motors: IP55.
• For operation in condensing environments (liquid temperature lower than ambient), a motor suited for such conditions must be used. Outdoor installations require a protective cover.

Sound Pressure Level (LpA) for CM pumps (tolerance 3 dB[A]):

• CME pumps reduce noise at partial load due to lower motor speed.

Pumped liquids

The pumps are designed for thin, non-explosive liquids, not containing solid particles or fibres. The liquid must not chemically attack the pump materials.

Considerations for pumped liquids:

• Density/Viscosity: Pumping liquids with densities or kinematic viscosities higher than water will cause a pressure drop, reduced hydraulic performance, and increased power consumption. Oversized motors may be required.
• Chemical Properties: Suitability depends on chloride content, pH value, temperature, and content of chemicals and oils. Aggressive liquids (e.g., seawater, some acids) may attack or dissolve the protective oxide film of stainless steel, causing corrosion.
• Special Conditions:
  • For liquids with high chloride content, continuous running (standstills not exceeding 6-8 hours) can minimize corrosion risk.
  • Some liquids may contain additives or impurities that can cause shaft seal problems.
  • For demineralised water with conductivity less than 2 µS/cm, a SiC/SiC shaft seal is unsuitable; a ceramic/carbon shaft seal combination should be used instead.
  • If oil residues are present, EPDM cannot be used.
  • Flammable or combustible liquids require safety precautions; a seal-less pump may be required.
  • Risk of crystallisation/precipitation on the shaft seal for certain liquids.

An extensive list of typical liquids and their compatibility with different pump materials and shaft seals is available in the official PDF. This list serves as a general guide and cannot replace actual testing under specific working conditions.

Electrical

Motors:

• Totally enclosed, fan-cooled, 2-pole motors, with principal dimensions to EN 50347.
• Electrical tolerances comply with EN 60034.
• Insulation class: F.
• Enclosure class: IP55.
• Single-phase motors are standard up to and including 1.1 kW.
• Three-phase motors are available from 1.1 to 7.5 kW.
• CME pumps are fitted with high-efficiency motors as standard. CM pumps with three-phase motors (1.1 to 7.5 kW, 380-415 V) are available with high-efficiency motors on request.

Supply Voltages (tolerance ± 10 %):

• CM pumps:
  • 1 x 220 V, 60 Hz
  • 1 x 115/230 V, 60 Hz
  • 1 x 220-240 V, 50 Hz
  • 1 x 127 V, 60 Hz
  • 3 x 208-230/440-480 V, 60 Hz
  • 3 x 220-240/380-415 V, 50 Hz
  • 3 x 200/346 V, 50 Hz; 200-220/346-380 V, 60 Hz
  • 3 x 575 V, 60 Hz
  • 3 x 400 V, 50/60 Hz (currently 60 Hz only, dual frequency expected Jan 2011)
  • 3 x 380-415 V, 50 Hz; 440-480 V, 60 Hz
  • 3 x 220-240/380-415 V, 50 Hz; 3 x 220-255/380-440 V, 60 Hz
• CME pumps:
  • 1 x 200-240 V, 50/60 Hz
  • 3 x 380-480 V, 50/60 Hz
  • 1 x 208-230 V, 50/60 Hz
  • 3 x 460-480 V, 60 Hz

Motor Protection:

• Mains-operated motors (CM):
  • Single-phase, 1 x 115/230 V, 60 Hz motors require an external, manually resettable motor-protective circuit breaker.
  • Other single-phase motors have built-in current- and temperature-dependent motor protection (IEC 60034-11, TP 211 type) with automatic reset.
  • Three-phase motors up to 3 kW require an external, manually resettable motor-protective circuit breaker.
  • Three-phase motors 3 kW and up (for supply voltages F, G, O) have built-in thermistors (PTC) (DIN 44082, TP 211 type) with automatic reset. Motors for other supply voltages require an external motor-protective circuit breaker.
• Electronically speed-controlled motors (CME): No external motor protection is required. The MGE motor incorporates thermal protection against slow overloading and blocking (IEC 34-11: TP 211).

Frequency Converter Operation:

• All three-phase motors can be connected to a frequency converter.
• May cause increased acoustic noise and detrimental voltage peaks (above 650 V peak between supply terminals for standard MG 71- and MG 80-based motors without phase insulation).
• An LC filter can be fitted between the frequency converter and motor to mitigate these issues. Phase-insulated MG 71- and MG 80-based motors are available on request.

Mechanical / hydraulic

Pump Construction:

• Non-self-priming, horizontal, multistage centrifugal pumps.
• Axial suction port and radial discharge port.
• Mounted on a base plate.
• All movable parts are made of stainless steel.

Performance Range:

• Performance curves for CM (50 Hz, 60 Hz) and CME (50/60 Hz) pumps are available in the official PDF, showing head (H) versus flow (Q) for various models (CM 1, CM 3, CM 5, CM 10, CM 15, CM 25).
• The 100 % speed of CME pumps is approximately 3400 min⁻¹, irrespective of input frequency.
• See the official PDF for exact tabulated values and performance curves.

Minimum Inlet Pressure (NPSH): To avoid cavitation, a minimum pressure on the suction side of the pump is required. The maximum suction lift "H" in metres head can be calculated as: H = pb x 10.2 - NPSH - Hf - Hv - Hs Where:

• pb: Barometric pressure in bar (can be set to 1 bar, or system pressure in closed systems).
• NPSH: Net Positive Suction Head in metres head (read from the NPSH curve at the highest flow).
• Hf: Friction loss in suction pipe in metres head (at the highest flow).
• Hv: Vapour pressure in metres head (depends on liquid temperature "Tm").
• Hs: Safety margin = minimum 0.5 metres head. Always check the NPSH value at the highest possible flow to avoid cavitation.

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Disclaimer: This summary is based on extracted text and may not include all figures, footnotes, or the latest revisions from the original OEM PDF datasheet. Contractual data must always match the specific OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror