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3 Product Description
• Early warning: "B"-alarm
• Pump stop: "A"-alarm
3.4.4 Stator temperature monitoring methods
The purpose of stator winding temperature monitoring is to make the motor shut off at high
temperature. There are several monitoring methods, depending on the voltage of the motor,
and types of thermal sensors chosen.
By using an analogue sensor, two adjustable alarm limits can be used, one for warning ("B"-
alarm) and one for pump stop ("A"-alarm). The configurations which can be used for
monitoring the stator winding temperature depend upon the voltage range of the drive unit.
See
Up to 1 kV drive units
Table 1: Stator temperature monitoring configuration, up to 1 kV
Standard / Optional
Standard
Optional
3.4.4.1 Temperature sensors
Table 2: Thermal contact
Description
The thermal
contact is a
normally closed
contact.
Table 3: PTC thermistor
Description
The PTC
thermistor is a
semiconductor
device.
12
Drive units
on page 10 for the voltage range for each drive unit.
Monitoring configuration description
• Three thermal contacts, connected in series, are incorporated in the coil ends
of the stator winding. The contacts are normally closed, and open at 140°C
(285°F).
• One Pt100 sensor is incorporated in one of the windings.
• Three thermistors, PTC, connected in series, are incorporated in the coil ends
of the stator windings. T
• One Pt100 sensor is incorporated in one of the windings.
• Three thermal contacts, connected in series, are incorporated in the coil ends
of the stator winding. The contacts are normally closed, and open at 140°C
(285°F).
• Three Pt100 sensors, one for each phase, are incorporated in the windings.
• Three thermistors, PTC, connected in series, are incorporated in the coil ends
of the stator windings. T
• Three Pt100 sensors, one for each phase, are incorporated in the windings.
Measured value
0–3 ohm, unless the wires are long.
Measured value
Resistance at normal temperature:
• 50–100 ohm (150–300 ohm for three in
series).
Or:
=140°C (285°F).
Ref
Or:
=140°C (285°F).
Ref
Fault values
An infinite value (open circuit) indicates
either high temperature or a fault.
Examples of faults include a broken wire,
or a bad contact in a connector.
Fault values
• Above the tripping point, T
resistance increases dramatically to
several kilohm.
• An infinite value (open circuit)
indicates a fault. Examples of faults
include a broken wire, or a bad
contact in a connector.
• A value close to zero indicates a short
circuit in the wiring.
P7900 Installation, Operation, and Maintenance Manual
, the
Ref
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