Thermal Switches; Moisture Switch - Grundfos S2 Instrucciones De Instalación Y Funcionamiento

IO 113
Analog and digital
outputs
P
L1 L3
L2
Power
side
"d" enclosure
WIO sensor
"mb" approval
Fig. 32 Sensor connections, SM 113 outside motor
Legend for fig. 32:
Symbol Description
T Thermal switch
M

Moisture switch

P Power input
S Sensor input
SM 113 Sensor board
IO 113 IO 113 with internal alarm relay (250 VAC)
"d" Flameproof enclosure
Protection according to EN/IEC 60079-18:2004 and
"mb"
60079-0:2004
SM 113
S
Signal
side

8.4.1 Thermal switches

The thermal protection against overheating is achieved with
bimetallic switches as standard or thermistors as optional. The
three thermal switches that are hardwired from the pump to IO
113, or similar controller, will open if the stator windings become
too hot. The thermal switches are of the reversible type and will
close again when the motor has cooled down.
This generates both a hardware and a software alarm in IO 113,
and the alarm relay will open.
Install an automatic circuit breaker, which
disconnects the power supply in case the thermal
switches or the moisture switches are not operating.
8.4.2 Moisture switch
The pumps have two moisture switches, one below the motor top
cover and one in the stator housing. The moisture switches are of
the irreversible type and must be replaced if activated.
The moisture switches are hardwired from the pump to IO 113, or
similar controller. They will open if moisture is detected and thus
break an electric circuit. This will generate both a hardware and a
software alarm in IO 113, and the alarm relay will open.
8.4.3 Pt100
Pumps are equipped with Pt100 sensors in the stator windings, in
the upper bearing bracket and in the lower bearing bracket.
Pt100 makes an analog measurement from 32-356 °F (0-180 °C.)
The value is measured by SM 113 and transferred to IO 113
through serial communication.
If the pump does not have an SM 113, hardwire the Pt100
sensors out of the pump and connect them to an external unit.
See fig. 32. If the pump has an SM 113, connect the Pt100
sensors to SM 113. No external unit is required.
Maximum alarm temperatures can be seen in table below:
Alarm temperatures
Winding
Pump range
temperature
[°F (°C)]
72 302 (150)
74 302 (150)
78 302 (150)
Upper Lower
bearing bearing
[°F (°C)] [°F (°C)]
248 (120) 212 (100)
248 (120) 248 (120)
248 (120) 248 (120)
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