Operation; Switching On/Off; Setting The Dosing Capacity; Using The Ar Control Unit (Optional) - Grundfos DMH 25 Serie Montage- Und Betriebsanleitung

9. Operation

9.1 Switching on/off

Before switching on the pump, check that it is
Caution
installed correctly. See sections
8. Start-up/shutdown
• To start the pump, switch on the power supply.
• To stop the pump, switch off the power supply.

9.2 Setting the dosing capacity

Fig. 31 Setting the dosing capacity
Pos. Components
L Stroke-length adjustment knob
1l Cover
2l Locking screw
3l Screw
4l Scale ring
9.2.1 Setting the dosing flow and locking the stroke-length
adjustment knob
1. Remove the cover (1l) from the stroke-length adjustment knob
(L).
2. Use a screwdriver to loosen the locking screw (2l) by
approximately 2 turns.
3. Increase or reduce the dosing flow while the pump is running.
– Slowly turn the stroke-length adjustment knob to the left or
right to set the desired dosing volume.
4. Depending on the application, tighten the locking screw (2l) so
that the stroke-length adjustment knob can still be
turned/cannot be turned any more.
5. Replace the cover (1l).
The pump cannot be operated if the stroke-length
adjustment knob is fully open! Depending on the
pump adjustment, this value may already be lower
than 100 % on the scale for system pressures higher
Caution
than 100 bar.
Open the stroke-length adjustment knob completely
and then close by approx. 10 % in order to set the
dosing flow to 100 %.

9.3 Using the AR control unit (optional)

When using the AR control unit, observe the installation and
operating instructions for the "AR control unit" in addition to the
instructions in this manual.

9.4 Electric servomotor (optional)

To operate the servomotor, see the installation and operating
instructions for the servomotor.

9.5 Electronic preselection counter (optional)

To operate the preselection counter, see the installation and
operating instructions for the counter.
30
6. Installation and
.
3l 2l 1l
3l
L
4l

9.6 Electrically heated dosing head (optional)

To operate the temperature controller, see the installation and
operating instructions for the temperature controller.
10. Maintenance

10.1 General notes

Warning
When dosing dangerous media, observe the
corresponding safety precautions!
Wear protective clothing (gloves and goggles) when
working on the dosing head, connections or lines!
The pump housing must only be opened by
personnel authorised by Grundfos!
Repairs must only be carried out by authorised and
qualified personnel!
Switch off the pump and disconnect it from the power
supply before carrying out maintenance work and
repairs!
Before removing the dosing head, valves and lines,
empty any remaining medium in the dosing head into
a drip tray by carefully unscrewing the suction valve.
Observe the flow direction of valves (indicated by an
arrow on the valve)!
Caution
Only tighten plastic valves by hand.
10.2 Diaphragm leakage control for diaphragm
leakage detection
If a diaphragm leakage has been detected, first of all check
whether an error has been displayed, as different external factors
such as the heating of dosing or hydraulic medium can cause the
cracked medium between the diaphragms to be displaced into the
valve, thereby causing an error to occur.
Checks after a diaphragm leakage detection:
1. Briefly open the deaeration screw (2u) and then close it again.
2. Switch on the pump.
3. If, after a short period of time, a diaphragm leakage is
detected again, a diaphragm has broken.
After a diaphragm breakage, replace the diaphragms
and clean the non-return valve, see section
Caution
10.7 Replacing the diaphragm for dosing head with
double diaphragm .
1u
Fig. 32 Dosing head with double diaphragm
Pos. Components
S Contact pressure gauge
T Ball non-return valve
U Connection piece
1u Filling screw
2u Deaeration screw
S
U
2u
T