Impeller Diameter; Pumped Liquids; Technical Data; Ambient Temperature - Grundfos NB Series Installation And Operating Instructions Manual

3.3 Impeller diameter

At the customer's request, the impeller diameter may have been
changed to allow the pump to match a specified duty point. This
means that the actual impeller diameter differs from the standard
diameters stated in sales catalogues, data sheets, etc.
The actual impeller diameter can be found on the pump name-
plate.

3.4 Pumped liquids

Clean, thin, non-explosive liquids without solid particles or fibres.
The pumped liquid must not attack the pump materials chemi-
cally.
When pumping liquids with a density and/or viscosity higher than
that of water, motors with correspondingly higher outputs must be
used, if required.
O-rings and the mechanical shaft seal chosen must be suitable
for the liquid to be pumped.
Special shaft seals may be required if the pump is used for pump-
ing treated water at temperatures above 80°C containing addi-
tives to prevent system corrosion, calcareous deposits, etc., for
instance in heating and ventilating systems.
Another type of shaft seal may also be required for the pumping
of glycol-containing liquids.
For heating systems, the water quality should meet VDI 2035.
Contact Grundfos for further information.

4. Technical data

4.1 Ambient temperature

The ambient temperature and the installation altitude are impor-
tant factors for the motor life, as they affect the life of the bearings
and insulation system.
Maximum ambient temperature:
• EFF2 motors: +40°C.
• EFF1 motors: +60°C.
If the ambient temperature exceeds +40°C (+60°C), or the motor
is installed more than 1000 m (3500 m) above sea level, the
motor must not be fully loaded due to the low density and conse-
quently low cooling effect of the air. In such cases, it may be nec-
essary to use a motor with a higher output.
P2
[%]
100
90
80
70
60
50
20 25 30 35 40 45 50 55 60 65 70 75 80
1000 2250
Fig. 5 Motor P2 in relation to temperature/altitude

4.2 Liquid temperature

–25°C to +140°C.
The maximum liquid temperature is stated on the pump name-
plate. It depends on the shaft seal chosen.
For pump housing of cast iron EN-GJL-250 local regulations may
not allow liquid temperatures above +120°C.
EFF 1
EFF 2
t [°C]
m
3500 4750

4.3 Operating pressure

The maximum operating pressure is stated on the nameplate.
NB:
Maximum 1.6 MPa (16 bar).
DN 200: 1 MPa (10 bar).
NBG:
Maximum 1.6 MPa (16 bar).

4.4 Min. inlet pressure

According to the NPSH curve of the pump (see page 477) + a
safety margin of minimum 0.5 m head.
The procedure for the calculation of the minimum inlet pressure is
shown in 13. Calculation of minimum inlet pressure.

4.5 Maximum inlet pressure

The actual inlet pressure + pressure when the pump is running
against a closed valve must always be lower than the maximum
operating pressure.

4.6 Minimum flow rate

The minimum flow rate must be at least 10% of the maximum flow
rate. The flow rate and head are stated on the pump nameplate.

4.7 Maximum flow rate

The maximum flow rate must not exceed the values stated for the
individual pump on page 463, as otherwise there is a risk of for
instance cavitation and overload.

4.8 Electrical data

See the motor nameplate.

4.9 Weight

See label on the packing.

4.10 Sound level

See table on page 461.
The values stated are maximum values, including the upper toler-
ance of 3 dB according to ISO 4871.

4.11 Pump speed relative to material and size

Ø [mm] 650
600
550
500
450
400
350
300
250
200
1200 1600 2000 2400
Fig. 6 Maximum permissible speed
For stainless steel pumps (1.4408/1.4517) there is no limit in the
range shown.
CuSn10
EN-GJL-200
-1
2800 3200 3600 min
11