Grundfos SE Serie Notice D'installation Et De Fonctionnement page 18

7.3.2 Thermistors
PTC thermistors are available as accessories or Factory Product
Variants (FPV).
The thermistors can be used as motor protection devices to monitor
stator temperature instead of thermal switches and must be
connected to the thermistor relay in the control cabinet.
The operating voltage of PTC thermistors is 2.5 - 7.5 V.
Checks after electrical connection
1. Check whether the circuit resistance is below 150 Ω per
thermistor, with a multimeter.
2. Check whether the insulation between circuit and stator housing
is outside the range, with a multimeter.
3. Carry out a similar measurement at the end of the power supply
cable.
Pt1000 temperature sensor
The Pt1000 temperature sensor is available as an accessory or an
FPV.
The Pt1000 sensor is primarily used for the monitoring of bearing
temperature, but it can also be used in the stator.
In case of overheating, the Pt1000 sensor trips an alarm and
disconnects the power supply at a preset temperature.
The bearing temperature monitoring system is only
available as an option.
The sensor resistance values are the following:
• 1000 Ω at 32 °F (0 °C)
• 1385 Ω at 212 °F (100 °C)
• approximately 1078 Ω at room temperature.
The temperature limits are the following:
• 194 °F (90 °C): warning for bearing temperature
• 266 °F (130 °C): pump stop caused by high bearing temperature
• 302 °F (150 °C): pump stop caused by high stator temperature.
In FM-approved pumps, the maximum acceptable alarm
temperature in the bearing sensors is 212 °F (100 °C) for
FM
the lower bearing (shaft end) and 248 °F (120 °C) for the
upper bearing.
Checks after electrical connection
1. Check whether the resistance at room temperature [68 °F (20
°C)] is approximately 1078 Ω, with a multimeter.
2. Check whether the insulation between the circuit and the stator
housing is outside the range, with a multimeter.
3. Carry out similar measurements at the end of the power supply
cable.
During the pump check, the Pt1000 sensor must be connected to a
recording device.
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7.3.3 Pump vibration sensor (PVS3)
The PVS3 sensor monitors the vibration level to protect the pump
and the pipe network against damage.
A change in the vibration level iindicates an abnormal situation.
Make sure that a service inspection is carried out before the pump
or the pipe network is damaged.
The pumps are fitted with S-tube® impellers. The S-tube®
impellers are wet-balanced to reduce vibrations during
operation. If these pumps are started with the pump
housing containing air, the vibration level can be higher
than in normal operation.
SM 113
The SM 113 module is used for collecting and transferring sensor
data. SM 113 works with IO 113 through power line communication
using the Grundfos GENIbus protocol.
SM 113 collects data from the following devices:
• 3 current sensors, 4-20 mA
• 3 Pt1000 thermal sensors
• 1 PTC thermal sensor
• 1 digital input.
SM113 is fitted with a 2.7 kΩ resistor to avoid false sensor
alarms in the IO113.
IO 113
The IO 113 module is the interface between a 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 IO 113.
With the sensors, IO 113 is a galvanic separation between the
motor voltage in the pump and the connected controller.
IO 113 enables the following functions:
• overtemperature protection
• monitoring the sensors for analog measurement of:
- motor winding temperature
- pump vibrations
- stator insulation resistance
- bearing temperature
- moisture in the motor
• stopping the pump in case of alarm
• monitoring the pump remotely through RS485 communication
(Modbus or GENIbus).
Measurement of stator insulation resistance
IO 113 measures the insulation resistance between a stator winding
and ground:
• resistance above 10 MΩ = ok
• resistance between 10 MΩ and 1 MΩ = warning
• resistance below 1 MΩ = alarm.