8. Fault finding the product
8.1 The dosing pump does not run
Cause
Remedy
The pump is not connected to the power supply.
Connect the power supply cable.
Incorrect supply voltage.
Replace the dosing pump.
Electrical failure in the motor or the pump control unit.
Return the pump for repair.
The level sensor in the supply tank has stopped the pump,
because the tank is empty.
Refill the tank and start the pump.
The diaphragm leakage sensor has stopped the pump, be-
cause there is a leakage.
Replace the diaphragm and start
the pump.
8.2 The dosing pump does not suck in
Cause
Remedy
The inlet line is leaking.
Check and seal or replace the inlet line.
The inlet line is too small or too long.
Check with Grundfos specifications and adapt the
inlet line to the specifications.
The inlet line is clogged.
Clean or replace the inlet line.
The foot valve is covered by sediment.
Clean the foot valve.
Clean the tank from the sediment or shorten the in-
let line.
The inlet line is buckled.
Install the inlet line correctly. Check for damage.
There are crystalline deposits in the valves. Clean the valves.
The dosing diaphragm is broken.
Replace the dosing diaphragm.
8.3 No dosing flow
Cause
Remedy
There is air in the inlet line and the dosing
head.
Wait until the pump has deaerated.
The stroke-length adjusting knob is set to
zero.
Turn the stroke-length adjusting knob.
The viscosity of the dosing medium is too
high.
Make sure the dosing pump and the installation are
suitable for the viscosity of the dosing medium.
There are crystalline deposits in the valves. Clean the valves.
The valves are not assembled correctly.
Assemble the valve parts in the right order. Ensure
correct flow direction.
The injection point is blocked.
Ensure correct flow direction (injection unit). Re-
move the obstruction.
The lines and peripheral equipment are in-
stalled incorrectly.
Install the lines and peripheral equipment correctly.
Ensure free passage.
DMX 221 | |
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