Thermal Switches - Grundfos SE Instrucciones De Instalación Y Funcionamiento

4.2.3 Sensors
The SE, SL pumps, 12-42 hp (9-30 kW), can be equipped with a
variety of switches and sensors for protection. The specification
table below shows which switch and sensor types can be used for
which pump types.
The wiring diagrams of the various types of switch and sensor
appear from appendix, section
2. Sensor
Thermal switches/PTC
Moisture switch, top
Leakage switch
Pt1000 in stator winding
Pt1000 in upper bearing
Pt1000 in lower bearing
PVS3 vibration sensor
SM 113
IO 113
Switch and sensor specification table

Thermal switches

Three bimetallic thermal switches are built into the stator
windings, and a contact will open in case of overtemperature, i.e.
302 °F (150 °C); however, the motor insulation class is class H
356 °F (180 °C).
The supply voltage to the thermal switches must be 12-230 VAC.
The thermal switches are connected to the control cable and
must be connected to the safety circuit of the separate pump
controller.
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.
The installer or user must install an automatic circuit
breaker which disconnects the power supply in case
FM
the thermal switches or the moisture switches are not
working.
overview.
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Moisture switches
Non-Ex version:
There is one moisture switch and one leakage switch mounted in
a non-Ex pump. The moisture switch is placed in the top cover
and the leakage switch is placed in the chamber above the shaft
seal. See appendix, fig. 9, C-C and E-E.
Ex version:
There is one moisture switch and one leakage switch mounted in
an Ex pump. The moisture switch is placed in the top cover and
the leakage switch is placed in the stator housing. See appendix,
fig. 9, C-C and D-D.
All switches in both non-Ex and Ex versions are hardwired from
the pump to IO 113. If moisture or a leakage is detected, they will
break an electric circuit. This will generate both a hardware and a
software alarm in IO 113, and the alarm relay will open.
Moisture and leakage switches are motor protection devices,
which protect the motor from damage due to moisture or water
ingress. The switches are of a non-reversing type and must be
replaced after they have been released.
The moisture and leakage switches are connected in a separate
circuit and to the control cable. See appendix, section
diagrams. They are also to be connected to the safety circuit of
the separate pump controller.
Thermistors
Thermistors are available as an accessory or as an FPV (Factory
Product Variant) option.
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.
Checking after installing the pump
1. Using a multimeter, check whether the circuit resistance is <
150 Ω/thermistor.
2. Using a multimeter, check whether the insulation between
circuit and stator housing is outside the scale (not measurable
∞ ).
3. Carry out a similar measurement at the end of the power
supply cable.
1. Wiring
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