Temperature - GE 239 Instruction Manual

CHAPTER 5: MONITORING
5.3.3

Temperature

239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
• STATOR (BEARING) RTD1 (2-3) TEMPERATURE (OPTION): When enabled by
TEMPERATURE\RTD1-3\RTD1-3 APPLICATION
each RTD will be displayed. For RTDs installed in the stator, interpretation of the
temperature is more meaningful if the insulation class of the stator windings is known.
This value indicates how close the stator is operating to its maximum allowable
temperature. Consult the motor manufacturer's data for stator insulation class and
maximum operating temperature. Insulation life typically is reduced by half for every
10°C rise in temperature. Bearing temperatures vary with ambient conditions,
greasing, wear and loading. A significant increase in bearing temperature may
indicate a problem that needs investigation. Temperatures can be viewed in °C or °F
by selecting the appropriate setpoint in
.
DISPLAY IN
• THERMISTOR: Thermistors typically installed in motors for temperature detection are
nonlinear devices. When enabled, the thermistor readout will indicate hot or cold
depending on whether the thermistor resistance exceeds its alarm/trip threshold
setpoint. If the terminals are left unconnected while the thermistor function is set to
trip or alarm or the thermistor resistance increases above 31.5 kΩ,
THERMISTOR NOT CONNECTED
thermistor is not being used, the function must be set to off.
, the actual temperature measured by
S1: 239SETUP\PREFERENCES\TEMPERATURE
alarm message will be displayed. Therefore, if the
S4:
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