Protection And Control Functions; Motor Protection Devices; Galvanic Separation; Measurement Of Insulation Resistance - Grundfos S2 Instrucciones De Instalación Y Funcionamiento

8. Protection and control functions

8.1 Motor protection devices

The motors have three thermal protectors connected in series
and two moisture switches connected in series. Protectors and
switches are connected in two separate circuits. The thermal
protectors are of the reversible type, and the moisture switches
are of the irreversible type. The thermal protection circuit,
conductors 1 and 3, and the moisture protection circuit,
conductors 2 and 3, have separate outputs to enable separate
alarms if the motor is overheated or affected by moisture.
All other sensor connections are either led out of the motor,
sensor version D, via conductors 4 to 9, or connected to the
sensor board, sensor version B, and led out of the motor via
conductors 4 and 5.
8.2 IO 113
IO 113 forms the interface between a Grundfos sewage and
wastewater pump with analog and digital sensors and the pump
controller. The most important sensor data are indicated on the
front panel.
One pump can be connected to an IO 113 module.
Together with the sensors, IO 113 forms a galvanic separation
between the motor voltage in the pump and the controller
connected.
IO 113 can do the following as standard:
• protect the pump against overheating
• monitor the status of these items:
– motor winding temperature
– leakage via WIO
– moisture in pump.
• measure the stator insulation resistance
See section
8.2.2 Measurement of insulation
• stop the pump in case of alarm
• remotely monitor the pump via RS-485 communication,
Modbus or GENIbus
• control the pump via a frequency converter.
Combined with SM 113, IO 113 can monitor the bearing
temperature and rotor speed when the motor is switched off.

8.2.1 Galvanic separation

Double-insulated sensors for all measurements ensure the
electrical safety. Furthermore, there is a galvanic separation
inside IO 113.

8.2.2 Measurement of insulation resistance

IO 113 measures the insulation resistance between a stator
winding and earth:
• Resistance above 10 megaohm is ok.
• Resistance between 10 and 1 megaohm will cause a warning.
• Resistance below 1 megaohm will cause an alarm.
24

8.3 SM 113, optional

SM 113 is designed and used for the collection and transfer of
additional sensor data. SM 113 works together with IO 113 with
communication module, product number 98097390, as shown in
the figure below.
IO 113
T1 T2 G1 A1 G2 A2 K1 K2 R1 R2
D1 D2 D3 D4 D5 D6 D7 D8
ON
1 2 3 4 5 6 7 8 9 10 11 12
P1 P2 P3 P4 P5
Fig. 30 IO 113 and SM 113
SM 113 can collect data from these devices:
• Current sensors, 4-20 mA*
• Pt100**/ Pt1000*** thermal sensors.
* Vibration sensor, water-in-oil, WIO, or water-in-air, WIA,
sensor
** Maximum three Pt100 sensors
*** Maximum four Pt1000 sensors.

8.4 Switches and sensors

resistance.
Install an additional level switch to ensure that the pump is
stopped in case the primary stop level switch is not operating.
A pump includes the following switches and sensors:
• three thermal switches in the stator windings
• one moisture switch in the top cover
• one moisture switch in the stator housing
• three thermal protectors in the stator windings:
– one analog Pt100 sensor in the stator winding
– one analog Pt100 sensor in the upper bearing
– one analog Pt100 sensor in the lower bearing
• one analog WIO sensor in the oil chamber.
Fig. 31 Control cable seen towards the pump
PE
Power line
communication
A Y B
using Grundfos
GENIbus protocol
DIP
I1 I2 I3
Do not let the pump run dry.
Yellow and green
8
SM 113
1 2 3 4 5 6 7 8 9 1011 1213 14
Sensor inputs
9 3
1 4
2
7
5
6