Operation; Switching On/Off - Grundfos DMX 221 Montage- Und Betriebsanleitung

7. Commissioning
7.1 Checks before start-up
• Check that the rated voltage stated on the pump nameplate
corresponds to the local conditions!
• Check that all connections are secure and tighten,
if necessary.
• Check that the dosing head screws are tightened with the
specified torque and tighten, if necessary.
• Check that all electrical connections are correct.
7.2 Start-up
Before start-up, open the venting cartridge (pull cap
approx. 5 mm).
Caution
For transport or cleaning, the venting cartridge must
be closed.
After initial start-up and after each time the
diaphragm is changed, tighten the dosing head
screws.
Caution
After approximately 6-10 operating hours or two
days, cross-tighten the dosing head screws using a
torque wrench.
Maximum torque: 6 Nm.
1. Open the suction and discharge isolating valves (15, 16),
if installed.
2. Open the deaeration valve (17), if installed, in the discharge
line, or relieve the pressure on the discharge side so that the
medium can run out without a counterpressure.
3. Switch on the power supply.
4. Pumps with AR control unit only: Press the "Start/Stop" button
and keep it pressed.
– The pump switches to continuous operation.
5. Set the stroke-length adjustment knob to 100 %.
6. Leave the pump running until the dosed medium is free of air
bubbles.
7. Close the deaeration valve (17), if installed.
– The pump is now ready for operation.
17
15
Fig. 15 Initial start-up
16
16

8. Operation

In the event of a diaphragm leakage, the dosing
liquid may leak out of the hole in the intermediate
flange between the pump and the dosing head. The
parts inside the housing are protected from the
dosing liquid for a short time (depending on the type
Caution
of liquid) by the housing sealing. It is necessary to
check regularly (daily) if liquid is leaking out of the
intermediate flange. For maximum safety, we
recommend the pump version with diaphragm
leakage detection.
8.1 Description of the pump
9
7 4 3
5
6
Fig. 16 DMX 221
Pos. Components
1 Motor
2 Gears
3 Eccentric
4 Dosing diaphragm
5 Dosing head
6 Suction valve
7 Discharge valve
8 Stroke-length adjustment knob
9 AR control unit (optional)
10 Stroke sensor
Functional principle
• Reciprocating positive displacement pump with electric motor
and mechanical diaphragm control.
• The rotation of the motor is transformed into the reciprocating
movement of the dosing diaphragm by the eccentric and the
tappet.
• The dosing flow can be set by adjusting the stroke length of
the tappet.

8.2 Switching on/off

Before switching on the pump, check that it is
Caution
installed correctly. Refer to sections
and 7. Commissioning
• To start the pump, switch on the power supply.
• To stop the pump, switch off the power supply.
1 9
8
2
10
5. Installation
.