Connection; Base Plates For Securing Pump To Foundation; Pipeline Mounting; Pipework - Grundfos DNP series Montage- Und Betriebsanleitung

5.2 Connection

Arrows on the pump housing show the direction of flow of liquid
through the pump.
The pumps can be installed with the motor/pump shaft in all posi-
tions between vertical and horizontal, but the motor must never
fall below the horizontal plane, fig. 5.
Fig. 5
Isolating valves should be fitted on either side of the pump to
avoid draining the system if the pump needs to be cleaned or re-
paired.
Port-to-port lengths and flange dimensions are as shown in fig-
ures B and C, page 85.

5.3 Base Plates for Securing Pump to Foundation

Pumps fitted with motors up to and including 7.5 kW are fitted
with a mounting bracket (foundation bolts: M12), see fig. B on
page 85.
If the bracket is positioned inconveniently for the installation of
the pump, it can be removed and replaced to face the required di-
rection of mounting, see fig. A on page 85.
Pumps with motors of 11 kW and larger are supplied without a
mounting bracket. On these pumps, the motor is foot mounted to
slide rails (foundation bolts: M16), see fig. C on page 85.
The table on page 84 shows all dimensions required.
When floor mounted, concrete or similar solid foundations should
be provided for the pump.

5.4 Pipeline Mounting

Pumps fitted with motors up to and including 11 kW are suitable
for direct mounting in pipes, fig. 6.
Fig. 6
This type of installation does not allow the use of anti-vibration
mountings. To ensure quiet operation, the pipes should be sus-
pended from suitable pipe hangers.
70

5.5 Pipework

When installing the pipes, it must be ensured that the pump hous-
ing is not stressed by the pipework.
The suction and discharge pipes must be of an adequate size,
taking the pump inlet pressure into account.
Install the pipes so that air locks are avoided, especially on the
suction side of the pump, fig. 7.
Fig. 7

5.6 Bypass

The pump is not allowed to run against a closed dis-
charge valve as this will cause an increase in temper-
ature/formation of steam in the pump which may
cause damage to the pump.
If there is any danger of the pump running against a closed dis-
charge valve, a minimum liquid flow through the pump should be
ensured by connecting a bypass/a drain to the discharge pipe.
The drain can for instance be connected to a tank. A minimum
flow rate equal to 10% of the flow rate at maximum efficiency is
needed at all times. Flow rate and head at maximum efficiency
are stated on the pump nameplate.

6. Electrical Connection

The electrical connection should be carried out by an authorized
electrician in accordance with local regulations.
Before removing the terminal box cover and before
any removal/dismantling of the pump, make sure that
the electricity supply has been switched off.
The pump must be connected to an external mains
switch.
The operating voltage and frequency are marked on the name-
plate. Make sure that the motor is suitable for the electricity sup-
ply on which it will be used.
Single-phase GRUNDFOS motors incorporate a thermal switch
and require no additional motor protection.
Three-phase GRUNDFOS motors must be connected to a motor
starter.
All three-phase GRUNDFOS MG and MMG motors of 3 kW and
larger incorporate a thermal switch, TP 211. See the instructions
in the motor terminal box.
The terminal box can be turned to any of four positions, in 90°
steps.
If necessary, remove the coupling guards. Do not remove the
coupling.
Remove the bolts securing the motor to the pump. Turn the motor
to the required position. Replace and tighten the bolts.
Replace the coupling guards.
The electrical connection should be carried out as shown in the
diagram inside the terminal box cover.
Note: Do not start the pump until it has been filled with liquid and
vented.