100 Resistance Temperature Detectors - ABB AMA Manual

Manual for High Voltage Process Performance Motors
8.2.2 Pt-100 resistance temperature detectors
70 - Trouble Shooting
Examples of protections that, if they give an alarm or trip, may need further investigation:
• Diode fault protection
• High temperature in bearing, see Chapter 7.5 Maintenance of bearings and lubrication
system
• High temperature in winding or in cooling air, see Chapter 7.6 Maintenance of stator and
rotor windings.
• Overcurrent, current and voltage unbalance, bus bar voltage
• Vibration protection, Chapter 7.4.2 Vibration and noise.
Pt-100 resistance temperature detectors are an essential part in the machine's condition
monitoring and protection system. They are used to measure temperatures in the windings,
bearings and in the cooling air. The Pt-100 detector uses a fine platinum filament for the
temperature measurement, which can be damaged e.g. by incorrect handling or excessive
vibration.
The following symptoms might suggest a problem in a Pt-100 detector:
• Infinite or zero resistance over the detector
• Disappearance of measurement signal during, or after start up
• A significantly different resistance value in a single detector.
If a Pt-100 failure is suspected the findings should always be confirmed from the connection
box, by measuring the resistance at the detector with its cables disconnected. The findings
should by registered. For the correct measuring current see the appropriate Pt-100 detector. For
resistance values at different temperatures, see Table 8-1 Temperature values for Pt-100
elements.
3BFP 000 063 R0101 REV D