En
gl
is
h (
G
B)
6
3.4.3 Connection of wires in the terminal box
Carry out the electrical connection as shown in the
diagram inside the terminal box cover.
Fig. 4
Wiring diagram
3.4.4 Frequency converter operation
You can connect three-phase motors to a frequency
converter.
Depending on the frequency converter type, this may
cause increased acoustic noise from the motor.
Furthermore, it may cause the motor to be exposed
to detrimental voltage peaks.
*
MG 71- and MG 80-based motors with phase
insulation are available on request.
The above disturbances, i.e. both increased acoustic
noise and detrimental voltage peaks, can be
eliminated by fitting an LC filter between the
frequency converter and the motor.
For further information, please contact the frequency
converter supplier or Grundfos.
4. Starting up the product
4.1 Non-self-priming pumps
4.1.1 Liquid filling
1. Close the isolating valve on the outlet side of the
pump.
2. Open the isolating valve in the inlet pipe
completely before starting the pump.
3. Remove the filling plug. See fig.
4. Fill the pump housing and the inlet pipe
completely with liquid until a steady stream of
liquid runs out of the filling hole.
5. Fit and tighten the filling plug.
6. Start the pump and slowly open the outlet
isolating valve while the pump is running. This
ensures venting and pressure buildup during
startup.
Fig. 5
Position of filling hole and drain hole
T
M
0
5
0
5
2
9
1111
MG 71- and MG 80-based motors have no
phase insulation* and must therefore be
protected against voltage peaks higher
than 650 V (peak value) between the
supply terminals.
If there is a risk of condensation in the
motor, remove the motor drain plug before
startup and keep the drain hole open
during operation. See fig.
.
Do not start the pump until it has been
filled with liquid.
CAUTION
Hot or cold liquid
Minor or moderate personal injury
- Wear personal protective equipment.
- Pay attention to the direction of the vent
hole when you fill the pump with liquid
and vent it.
- Make sure that no persons are hurt by
the escaping liquid.
Pay attention to the direction of the vent
hole during liquid filling and venting. Make
sure that the escaping liquid does not
cause damage to the motor or other
components.
The outlet isolating valve must be opened
immediately after startup of the pump.
Otherwise, the temperature of the pumped
liquid may become too high and cause
damage to the equipment.
TM
05 05
30 1
11
1
If it is difficult for the pump to build up
pressure, it may be necessary to repeat
steps
.
Filling plug
Drain plug
Summary of Contents for CMV 3
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