Fault Finding Chart; Disposal - Grundfos DMM 4 Instrucciones De Instalación Y Funcionamiento

9. Fault finding chart

Fault
Motor is running, but Valve blocked or leaking.
the pump is not dosing.
Valves incorrectly installed.
Suction valve or suction line leak-
ing or blocked.
No stroke movement.
Pump dosing too little Stroke length control knob incor-
or too much. rectly installed.
Pump dosing too Suction pressure too high.
much.
Pump dosing irregu- Valve blocked or leaking.
larly.
Frequent diaphragm Diaphragm not fastened properly to
failures. the diaphragm rod.
Pressure surges at dosing strokes
too high.
Excessive counter-pressure.
Pump too noisy. Defective bearing.
No oil in gear box.
Motor hums and does Wrong connection.
not start.
Defective capacitor (single-phase
pumps only).
Excessive counter-pressure.

10. Disposal

Disposal of this product or parts of it must be carried
out according to the following guidelines:
1. Use the local public or private waste collection
service.
2. In case such waste collection service does not
exist or cannot handle the materials used in the
product, please deliver the product or any haz-
ardous materials from it to your nearest GRUND-
FOS company or service workshop.
Cause
Check and clean valves.
Reinstall valves. Ensure that the valve balls
are positioned above the valve seats.
Clean and seal suction line.
Return spring defective. Replace spring.
Check that counter-pressure and suction pres-
sure of pump are within the permissible range.
Install the knob correctly.
Install counter-pressure valve in discharge
line.
Check and clean valves.
Install new diaphragm to ensure that the dia-
phragm is fastened properly.
Install pulsation dampener.
Check counter-pressure and adjustment of
counter-pressure valve, if any.
Replace bearing.
Refill oil. Renew gear oil, if necessary.
Check electrical connection.
Check capacitor connection or replace it, if
necessary.
Check discharge line for blocking.
Remedy
Subject to alterations.
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