Adjusting The Dosing Flow Via The Stroke Length; Adjustment Of The Stroke Rate With A Frequency Converter; Opening And Reactivating The Integral Relief Valve - Grundfos DMX 221 Installation And Operating Instructions Manual

3.7 Adjusting the dosing flow via the stroke length

Make sure the pump was installed and started up correctly.
• To increase the dosing flow, turn the adjusting knob slowly to the left.
• To decrease the dosing flow, turn the adjusting knob slowly to the right.
Related information
• 3.2 Safety instructions and requirements for startup
• 5.1.1 DMX 221 components
• 5.1.2 Functional principle of the pump
• 9.6 Dosing curves

3.8 Adjustment of the stroke rate with a frequency converter

If a frequency converter is connected, the dosing flow can be adjusted by changing the stroke
rate. This can only be done in the range of 10-100 % of the maximum stroke rate.
For more information, read the installation and operating instructions of the frequency converter.
Related information
• 11.2 Pumps with VFD

3.9 Opening and reactivating the integral relief valve

• Make sure the pump was installed and started up correctly.
• Make sure the pump is running during this task.
A
Fig. 3.9-1 Knob positions
1. To open the relief valve, turn the relief-valve knob to position B.
The relief valve is open. Dosing medium and air can flow out through the overflow line.
2. To reactivate the relief valve, turn the relief-valve knob to position A.
The relief valve is reactivated and will open at the set opening pressure.
Related information
• 3.10 Setting the opening pressure of the integral relief valve
Only adjust the stroke length while the pump is running.
WARNING
Chemical hazard
Death or serious personal injury
● Wear protective clothing when working on the dosing head, connections or
lines.
● Collect and dispose of all chemicals in a way that is not harmful to persons or
the environment.
B
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