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Pumps with WIO sensor
Moisture switch
All pumps are fitted with a moisture switch as
standard with the moisture switch being connected
through the supply cable and connected to a
separate circuit breaker.
Frequency converter operation
All SL1 and SLV pump types are designed for
frequency converter operation to keep the power
consumption at a minimum.
To avoid sedimentation in the pipes, operate the
speed-controlled pump at a flow rate above 1 m/s.
In this product range, only negligible amount of
bearing currents occurs during frequency converter
operation.
For frequency converter operation, observe the
following:
•
Before installing a frequency converter, calculate
the lowest allowable frequency in the installation
in order to avoid zero flow.
•
Do not reduce the motor speed to less than 50 %
of rated speed.
•
Keep the flow velocity above 1 m/sec.
•
Let the pump run at rated speed at least once a
day in order to prevent sedimentation in the
piping system.
•
Do not exceed the frequency indicated on the
nameplate to avoid motor overload.
•
Keep the power cable as short as possible. The
peak voltage increases with the length of the
power cable. See data sheet for the frequency
converter used.
•
Use input and output filters on the frequency
converter. See data sheet for the frequency
converter used.
•
Use screened power cable if there is a risk that
electrical noise can disturb other electrical
equipment. See data sheet for the frequency
converter used.
CAUTION
Electric shock
- For safe installation
and operation of
pumps equipped with a
WIO sensor, an RC
filter is recommended.
If an RC filter is
installed to avoid any
kind of transients in the
installation, the RC
filter must be installed
between the power
connector and the
pump.
Pumps for hazardous locations must be
connected to a control box with a motor
protection relay with IEC trip class 10.
The thermal protection of explosion-proof
pumps must not restart the pump
automatically. This ensures protection
against overtemperature in potentially
explosive environments. In pumps with
sensor this is done by removing the short
circuit between terminals R1 and R2 in the
IO 113. See Electrical data in the
installation and operating instructions for
IO 113 (net.grundfos.com/qr/i/98097396).
The separate motor-protective circuit
breaker or controller must not be installed
in potentially explosive environments.
CAUTION
Electric shock
Minor or moderate
personal injury
- The motor-protective
circuit breaker of the
pump controller must
include a circuit which
automatically
disconnects the power
supply in case the
protective circuit for the
pump is opened.
If the motor is operated by a frequency
converter, the temperature class of the
explosion-proof pumps must be T3.
