Connecting The Power Supply Cable; Start-Up/Shutdown; Initial Start-Up/Subsequent Start-Up - Grundfos DMH 25 Series Installation And Operating Instructions Manual

7.5 Connecting the power supply cable

Warning
Disconnect the power supply before connecting the
power supply cable!
Before connecting the power supply cable, check
that the rated voltage stated on the pump nameplate
corresponds to the local conditions!
Do not make any changes to the power supply cable
or plug!
The assignment between the plug-and-socket
Caution
connection and the pump must be labelled clearly
(e.g. by labelling the socket outlet).
The pump can be automatically started by
Caution
connecting the power supply!
• Do not switch on the power supply until you are ready to start
the pump.
7.5.1 Versions with mains plug
• Insert the mains plug in the mains socket.
7.5.2 Versions without mains plug
Warning
The pump must be connected to an external clearly
labelled mains switch with a minimum contact gap of
3 mm in all poles.
• Connect the motor to the power supply in accordance with
local electrical installation regulations and the connection
chart on the terminal box cover.
Warning
The specified enclosure class can only be ensured if
the power supply cable is connected with the same
degree of protection.
Observe the direction of rotation!
To protect the motor, install a motor protecting switch
Caution
or motor contactor, and set the bimetal relay to the
rated motor current for the available voltage and
frequency.

8. Start-up/shutdown

8.1 Initial start-up/subsequent start-up

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!
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.
The pump housing must only be opened by
personnel authorised by Grundfos!
Repairs must only be carried out by authorised and
qualified personnel!
Observe the flow direction of valves (indicated by an
arrow on the valve)!
Caution
Only tighten plastic valves by hand.
24
8.1.1 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.
• Cross-tighten the dosing head screws using a torque wrench.
Torques
Pump type
DMH 251, 10 bar
DMH 251, 16 bar
DMH 251, 25 bar
DMH 252
DMH 253
DMH 254
DMH 255
DMH 257
8.1.2 Oil filling
The pump is factory-checked, and the oil is drained
for shipping purposes. Before start-up, add the
special oil supplied with the pump.
Note
The piston flange is filled with oil for easy start-up.
The stroke-length adjustment knob must only be
adjusted if the gear oil has been added, otherwise
the oil will leak from the piston flange.
1. Slacken and remove the oil-filling screw (F).
2. Slowly add the hydraulic oil supplied with the pump through
the oil-filling opening (F) until the oil reaches the mark on the
oil dipstick.
3. Set the stroke-length adjustment knob (L) to "0".
8.1.3 Filling the dosing head for the initial start-up for
systems without flooded suction
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!
As assisting suction for systems without flooded suction, you can
fill the dosing head with dosing medium before the initial start-up:
1. Unscrew the discharge valve (3b).
2. Add the dosing medium to the dosing head (2).
3. Screw the discharge valve (3b) back in.
Observe the flow direction of the discharge valve
Note
(indicated by an arrow on the valve)!
Torque
[Nm]
8-10
10-12
13-15
8-10
10-12
50-54
50-54
50-54