The Pump Runs, But Delivers No Liquid; The Pump Starts, But The Motor-Protective Circuit Breaker Trips After A Short Time; The Pump Runs At Below Standard Performance And Power Consumption; Mechanical Shaft Seal Leaks, Sealing Chamber Monitor Reports Fault And Switches The Pump Off - Grundfos AP80-100 Montage- Und Betriebsanleitung

• See fault: Mechanical shaft seal leaks, sealing
chamber monitor reports fault and switches
the pump off.

9.2 The pump runs, but delivers no liquid

Cause
Outlet valve is closed or blocked.
Remedy
• Check the outlet valve and open and/ or clean
it, if necessary.
Cause
Non-return valve is blocked.
Remedy
• Clean the non-return valve.
Cause
There is air in the pump.
Remedy
• Vent the pump.
9.3 The pump starts, but the motor-
protective circuit breaker trips after a
short time
Cause
Low setting of the thermal relay in the motor-
protective circuit breaker.
Remedy
• Set the relay in accordance with the
specifications on the nameplate.
Cause
Increased power consumption due to large
voltage drop.
Remedy
• Measure the voltage between two motor
phases. Tolerance: - 10 %/+ 6 %. Re-establish
correct voltage supply.
Cause
The impeller is blocked by impurities. Increased
power consumption in all three phases.
Remedy
• Clean the impeller.
18
Cause
The impeller clearance is incorrect.
Remedy
• Dismantle and inspect hydraulic components
for wear, replace warn components if
necessary. The impeller clearance is not
adjustable.
9.4 The pump runs at below standard
performance and power consumption
Cause
The impeller is blocked by impurities.
Remedy
• Clean the impeller.
Cause
The direction of rotation is wrong.
Remedy
• Check the direction of rotation. If it is not
correct, interchange two phases in the power
cable.
9.5 Mechanical shaft seal leaks, sealing
chamber monitor reports fault and
switches the pump off
Cause
Increased leakage when running in new
mechanical shaft seals.
Remedy
• Change the oil.
Cause
Defective oil chamber seal probe.
Remedy
• Replace the oil chamber seal probe.
Cause
Mechanical shaft seal is defective.
Remedy
• Replace the mechanical shaft seal
• After a shaft seal has been removed from the
shaft, always replace with a new shaft seal.