Installation Altitude; Humidity; Maximum Operating Pressure; Minimum Inlet Pressure - Grundfos Hydro Multi-E Series Installation And Operating Instructions Manual

27.2

Installation altitude

Installation altitude is the height above sea level of the installation
site. Motors installed up to 1000 m above sea level can be loaded
100 %. The motors can be installed up to 3500 m above sea
level.
Motors installed more than 1000 m above sea level
must not be fully loaded due to the low density and
consequent low cooling effect of the air.
P2 [%]
100
90
80
70
60
0 500 1000 1500 2000 2500 3000 3500
Fig. 60 Motor output power in relation to altitude
In order to maintain the galvanic isolation and ensure correct
clearance according to EN 60664-1:2007, you must adapt the
supply voltage to the altitude:
P2 [%]
100
90
80
70
60
0 500 1000 1500 2000 2500 3000 3500
Fig. 61 Motor output power in relation to altitude
In order to maintain the galvanic isolation and ensure correct
clearance according to EN 60664-1:2007, you must adapt the
supply voltage to the altitude:
Supply voltage [V]
Y
500
480
460
440
420
400
380
500 1500
Fig. 62 Supply voltage for three-phase motor in relation to
altitude
Supply voltage [V]
250
240
230
220
210
200
0 500 1000 1500 2000 2500 3000 3500 4000
Supply voltage for single-phase motor in relation to altitude
Altitude [m]
Altitude [m]
2500 3500
X
Altitude [m]
Altitude [m]

27.3 Humidity

Maximum 95 %.

27.4 Maximum operating pressure

See system nameplate.

27.5 Minimum inlet pressure

Hf
Hf
H
H
pb
Pb
Fig. 63 Parameters for the calculation of minimum inlet
pressure
The minimum inlet pressure "H" in metres head required to avoid
cavitation in the pumps can be calculated as follows:
H = pb x 10.2 - NPSH - Hf - Hv - Hs
pb = Barometric pressure in bar. Barometric pressure can
be set to 1 bar.
In closed systems, p
in bar.
NPSH = Net Positive Suction Head in metres head
The NPSH value can be read from the NPSH curve at
the highest flow which the individual pump will be
delivering.
Hf = Friction loss in inlet manifold in metres head at the
highest flow the individual pump will be delivering.
Note: If a non-return valve is installed on the inlet
side of the pump, the friction loss in the valve must be
added. See the manufacturer's data.
Hv = Vapour pressure in metres head.
Hs = Safety margin of min. 0.5 metres head.
In some regions, the booster system is available with
a low inlet manifold which makes it more suitable for
suction lift operation. Contact Grundfos for further
information.
NPSH
NPSH
Hv
Hv
indicates the system pressure
b
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