Connecting The Suction And Discharge Lines; Electrical Connections; Connecting The Motor - Grundfos DMX 227 Instrucciones De Instalación Y Funcionamiento

5.5 Connecting the suction and discharge lines

Warning
All lines must be free from strain!
Only use the prescribed line types!
Depending on the material of the connection flanges (counter
flanges):
• Pipe and flange made of stainless steel: Weld the pipe to the
weld neck flange.
• Pipe and flange made of PP: Weld the pipe to the flange
sleeve.
• Pipe and flange made of PVC: Adhere the pipe to the flange
sleeve.
• The internal diameter of the lines, adapters and connectors
should not be smaller than DN 65. If necessary, use bends
instead of elbows.
• The suction lines must be designed in such a way that
cavitation is avoided.
Pulsation dampers should be fitted on both the
Caution
suction and discharge sides.
A positive pressure difference of 10 mWC is required
for correct operation of the dosing pump. If the total
of the counterpressure and the static difference in
height between the suction valve and the dosing
Note
point is less than 10 mWC, a pressure-loading valve
must be installed directly upstream of the dosing
point.
• Connect the suction line to the suction valve (A).
– Install the suction line in the tank so that the foot valve
remains 5 to 10 mm above the bottom of the tank or the
possible level of sedimentation.
• Connect the discharge line to the discharge valve (B).
To protect the dosing pump against excessive
pressure build-up, install a relief valve in the
Caution discharge line.
Make sure that the valves are seated correctly -
position of valve disk (C)!
Fig. 11 Connecting the suction and discharge lines
Pos. Components
A Suction valve
B Discharge valve
C Valve disk
14

6. Electrical connections

Make sure that the pump is suitable for the electricity supply on
which it will be used.
Warning
Electrical connections must only be carried out by
qualified personnel!
Disconnect the power supply before connecting the
power supply cable and the relay contacts!
Observe the local safety regulations!
Warning
The pump housing must only be opened by
personnel authorised by Grundfos!
Warning
Protect the cable connections and plugs against
corrosion and humidity.
Only remove the protective caps from the sockets
that are being used.
The power supply must be electrically isolated from
Caution
the signal inputs and outputs.
The pump is switched off by switching off the power
supply.
Note
Do not switch on the power supply until the pump is
going to be started.

6.1 Connecting the motor

• Connect the motor according to the wiring diagram in the
terminal box.
Observe the direction of rotation!
A motor protector, adjusted to the rated motor
current, must be provided by the customer.
When the pump is used with a frequency converter,
Caution
the jumpers in the terminal box have to be set
according to the converter voltage.
The jumpers of three-phase motors are factory-set
for star connection.