Grundfos SE1 50 Notice D'installation Et De Fonctionnement page 41

Cause
Increased current consumption due to large
voltage drop.
The impeller is blocked by impurities.
Increased current consumption in all three
phases.
Wrong direction of rotation.
10.3 The thermal switch of the pump trips after a short while
Cause
The liquid temperature is too high.
The viscosity of the pumped liquid is too high. •
Wrong electrical connection.
10.4 The pump operates at below-standard performance and power consumption
Cause
The impeller is blocked by impurities.
Wrong direction of rotation.
10.5 The pump operates but gives no liquid
Cause
The outlet valve is closed or blocked.
The non-return valve is blocked.
Air in the pump.
10.6 High power consumption (SEV)
Cause
Wrong direction of rotation.
The impeller is blocked by impurities.
10.7 Noisy operation and excessive vibrations (SE1)
Cause
Wrong direction of rotation.
The impeller is blocked by impurities.
10.8 The pump is clogged
Cause
The liquid contains large particles.
Remedy
• Measure the voltage between two motor phases.
Tolerance: -10 % to +6 %. Re-establish the
correct voltage supply.
• Clean the impeller.
• Clean the impeller.
• Check the direction of rotation and interchange
any two of the phases in the incoming supply
cable.
Remedy
• Reduce the liquid temperature.
Dilute the pumped liquid.
• Check and correct the electrical installation.
Remedy
• Clean the impeller.
• Check the direction of rotation and interchange
any two of the phases in the incoming supply
cable.
Remedy
• Check the outlet valve and open and/or clean it.
• Clean the non-return valve.
• Vent the pump.
Remedy
• Check the direction of rotation and interchange
any two of the phases in the incoming supply
cable.
• Clean the impeller.
Remedy
• Check the direction of rotation and interchange
any two of the phases in the incoming supply
cable.
• Clean the impeller.
Remedy
• Select a pump with a larger size of passage.
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