10. Technical data
10.1 Operating conditions
10.1.1 pH value
All the pumps can be used for pumping liquids with a
pH value between 4 and 10.
10.1.2 Liquid temperature
The permissible temperature is 0-40 °C.
If the motor is not fully loaded, the temper-
ature of the pumped liquid may be higher.
In this case, contact the nearest Grundfos
company or service workshop.
Explosion-proof pumps must never pump
liquids with a temperature higher than 40
°C.
10.1.3 Ambient temperature
The permissible temperature is -5 to +40 °C for S 72
and 0 to +40 °C for S 74-78 pumps.
For explosion-proof pumps, the ambient
temperature on the installation site must
be between -5 and +40 °C for S 72, and 0
and +40 °C for S 74-78 pumps.
10.1.4 Density and viscosity of the pumped liquid
Density: 1000 kg/m
3
.
Kinematic viscosity: 1 mm
2
/s (1 cSt).
When pumping liquids with a density
and/or a kinematic viscosity higher than
the values stated above, use motors with
correspondingly higher outputs.
10.1.5 Flow velocity
Keep a minimum flow velocity to avoid
sedimentations in the piping system.
Recommended velocities:
Vertical pipes:
0.7 m/s
Horizontal pipes:
1.0 m/s
10.1.6 Installation depth
The maximum submersion depth is 20 m.
10.1.7 Operating mode
The pumps are designed for continuous operation
with the maximum number of starts per hour stated in
the table below:
S pump, range
Starts per hour
72
15
74 and 78
10
10.1.8 Enclosure class
IP68.
10.1.9 Sound pressure level
CAUTION
Sound pressure level
Minor or moderate personal injury
‐
Use hearing protection when working
nearby an installation in operation. De-
pending on the installation type, the
sound pressure level of the pump can
exceed 70 dB(A).
10.1.10 Storage temperature
Storage temperature: -20 to +55 °C. Maximum 70 °C
for short periods not exceeding 24 hours according to
EN 60204-1.
10.2 Electrical data
Voltage tolerances for the motor and the motor
protection devices:
Component
Voltage
Tolerance
Motor
See the nameplate
± 10 %
Thermal
switches
Maximum 240 V
± 10 %
Thermistors
2.5 - 7.5 V
-
Moisture
switches
Maximum 240 V
-
Other sensors
Maximum 14 VDC
± 1 V
SM 113
Maximum 14 VDC
± 1 V
40
English (GB)
Summary of Contents for ST-55-520
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