Pump Controllers; Thermal Switch, Pt1000 And Ptc Thermistor; Wio Sensor (Water-In-Oil Sensor) - Grundfos SL1 Series Installation And Operating Instructions Manual

6.2 Pump controllers

SL1 and SLV pumps can be connected to the
following Grundfos pump controllers for level control:
• LC 231 or LC 241
• Grundfos DC and DCD.
For further information on controllers, see the
installation and operating instructions for the
selected controller or go to www.grundfos.com.
6.3 Thermal switch, Pt1000 and PTC
thermistor
All SL1 and SLV pumps have thermal protection
incorporated in the stator windings.
Pumps without sensor
Pumps without sensor have a thermal switch or a
PTC thermistor. Through the pump controller safety
circuit, the thermal switch will stop the pump by
breaking the circuit in case of overtemperature
(approximately 150 °C). The thermal switch will close
the circuit after cooling. For pumps equipped with a
PTC thermistor, connect the thermistor to either the
PTC relay or the I/O module to break the circuit at
150 °C.
The maximum operating current of the thermal
switch is 0.5 A at 500 VAC and cos φ 0.6. The switch
must be able to break a coil in the supply circuit.
Pumps with WIO sensor
Pumps with WIO sensor have either a thermal switch
and a Pt1000 sensor or a PTC thermistor in the
windings, depending on the installation site.
Through the pump controller safety circuit, the
thermal switch or the thermistor will stop the pump
by breaking the circuit in case of overtemperature
(approximately 150 °C). The thermal switch or the
thermistor will close the circuit after cooling.
The maximum operating current of both the Pt1000
and the thermistor is 1 mA at 24 VDC.
Non-explosion-proof pumps
When closing the circuit after cooling, the thermal
protection can restart the pump automatically
through the controller. Pumps from 4 kW and up sold
in Australia and New Zealand are fitted with a PTC
thermistor.
Explosion-proof pumps
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.

6.4 WIO sensor (water-in-oil sensor)

The WIO sensor measures the water content in the
oil and converts the value into an analogue current
signal. The two sensor conductors are for power
supply and for carrying the signal to the IO 113. The
sensor measures the water content from 0 to 20 %. It
also sends a signal if the water content is outside the
normal range (warning), or if there is air in the oil
chamber (alarm). The sensor is fitted in a stainless-
steel tube for mechanical protection.
Fig. 12 WIO sensor
6.4.1 Fitting the WIO sensor
Fit the sensor next to one of the shaft seal openings.
See Fig. 12. The sensor must be tilted into the
motor's direction of rotation to ensure that oil is led
into the sensor. Make sure that the sensor is
submerged in the oil.
6.4.2 Technical data
Input voltage:
Output current:
Power input:
Ambient temperature:
See also the installation and operating instructions
for IO 113 on www.grundfos.com.
12-24 VDC
3.4 - 22 mA
0.6 W
0-70 °C
19