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15. Technical data
15.1 Pressure
Inlet pressure
A positive inlet pressure is required before startup
and during operation.
We recommend that you calculate the inlet pressure in these
cases:
•
Water is drawn through long pipes.
•
Inlet conditions are poor.
In this document, the term "inlet pressure" is defined
as the pressure or vacuum which can be measured
immediately before the booster system.
To avoid cavitation, make sure that there is a minimum inlet
pressure on the inlet side of the booster system. The minimum
inlet pressure in psi can be calculated as follows:
H
=
P
- NPSH - H
- H
b
f
v
Barometric pressure in feet (33.9 feet at sea level).
P
=
In closed systems, p
b
feet.
Friction loss in suction piping in feet. (At the highest
H
=
f
flow the pump will be delivering.)
H
=
Vapor pressure in feet.
v
NPSH =
Net Positive Suction Head in feet.
NPSH can be read from the NPSH curve at the maximum
capacity at which the pump will run.
See Grundfos CM, CME Data booklet 98435269 / L-CM-PG-001.
H
=
Safety margin = minimum 2 feet
s
If "H" is calculated as positive, the pump can operate
at a suction of maximum "H" feet. If "H" is calculated
as negative, an inlet pressure (psia) of minimum "H"
feet is required.
P (psi) =
H/2.31
Maximum inlet pressure
The actual inlet pressure plus the pressure when the pump is
operating against a closed valve must always be lower than the
maximum system pressure.
Operating pressure
As standard, the maximum operating pressure is 232 psi (16 bar).
15.2 Temperature
Liquid temperature: 0 to 140 °F (0 to 60 °C).
Ambient temperature: 0 to 104 °F (0 to 40 °C).
15.3 Relative humidity
Maximum 95 %.
- H
s
indicates system pressure in
b
15.4 Sound pressure level
See the installation and operating instructions for the CM pumps.
The sound pressure level for a number of pumps can be
calculated as follows:
Lmax
= Lpump + (n - 1) x 3
Lmax
= Maximum sound pressure level
Lpump
= Sound pressure level for one pump
n
= Number of pumps
Considering the flow in pipes, vibrations, etc., the
actual sound pressure level of the booster system
will be lower than 90 dB(A).
15.5 Electrical data
Supply voltage
See the nameplate.
Digital inputs
Open-circuit voltage
Closed-circuit current
Frequency range
All digital inputs are supplied with PELV voltage
(Protective Extra-Low Voltage).
Analog inputs
Input current and voltage
Tolerance
Repetitive accuracy
Input resistance, current
Input resistance, voltage
Supply to sensor
All digital inputs are supplied with PELV voltage
(Protective Extra-Low Voltage).
Digital outputs (relay outputs)
Normally open contacts
(DO1, DO2 and DO3)
Normally closed contacts
(DO4 and DO5)
Optional tank fill panel auxiliary contacts
High level, (DO6)
Low Level, (DO7)
Maximum contact load
Minimum contact load
All digital outputs are potential-free relay contacts.
Some outputs have a common C terminal. For further
information, see the wiring diagram supplied with the
booster system.
24 VDC
5 mA, DC
0-4 Hz
0-20 mA
4-20 mA
0-10 V
± 3.3 % of full scale
± 1 % of full scale
< 250 Ω
10 kΩ ± 10 %
24 V, maximum 50 mA per
sensor, short-circuit-protected
C, NO
C, NC, NO
C, NO
C, NC
240 VAC, 2 A
5 VDC, 10 mA
19
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