GE 239 Instruction Manual page 69

4 PROGRAMMING
• RTD 1-3 APPLICATION: RTDs can be located in the stator windings or the bearings. Specify the
location of each RTD in this setpoint. The application name selected here will be displayed as
part of the alarm and trip message. If a particular RTD input is not used, this setpoint should be
set to off.
• RTD 1-3 TYPE: This setpoint must be programmed to the type of RTD for each of the RTDs con-
nected. The factory default is 100 Ω platinum but 100 Ω nickel, 120 Ω nickel, or 10 Ω copper can
also be connected to each input.
• RTD 1-3 TRIP and RTD 1-3 ALARM: Alarm and trip settings for stator RTDs depend on the
motor stator insulation type. Class B insulation rating is the factory default with alarm and trip lev-
els of 110°C and 130°C respectively. Higher temperatures can be selected for other insulation
classes. Consult the motor manufacturer for suitable settings if higher temperature insulation is
installed in the motor. Bearing temperature settings are empirically set. Default settings are 75°C
alarm and 90°C trip. The alarm/trip will occur immediately after the input becomes equal to or
exceeds the temperature setting. Once a motor is running for several hours the actual tempera-
ture can be monitored and the settings reduced. Over time a bearing problem such as a loss of
lubricant will show up as an increased temperature. Consequently, a setting close to the actual
operating temperature is desirable providing it does not generate nuisance alarms from ambient
temperature changes or load variations.
Temperature display units are set as either Celsius or Fahrenheit depending on the selection of
the setpoint 6  6(783?35()(5(1&(6?7(03(5$785( ',63/$< . RTD temperature readings from all
of the RTDs may be displayed. If RTD application is set to 2)) , the display for that RTD will be "no
RTD". When the setpoint 6  6(783?35()(5(1&(6?7(03(5$785( ',63/$< is changed from Cel-
sius to Fahrenheit or vice versa , setpoints 6 3527(&7,21?7(03(5$785(?57' ?57'  75,3 and
6 3527(&7,21? 7(03(5$785(?57' ?57'  $/$50 will automatically be scaled to the proper set-
ting.
c) RTD SENSOR FAILURE
• RTD SENSOR FAILURE ALARM: If an RTD becomes open circuited during use, the ACTUAL
VALUES display for that RTD will be "no RTD". Readings from the disconnected RTD will then be
ignored for overtemperature protection. The 239 relay will generate an alarm to warn of the faulty
RTD if this setpoint is enabled. Setpoints 6 3527(&7,21?7(03(5$785(?57' ?57'  75,3 and
6 3527(&7,21?7(03(5$785(?57' ?57'  $/$50 should be set to off for any unused RTD ter-
minals.
GE Multilin
Courtesy of NationalSwitchgear.com
239 Motor Protection Relay
4 PROGRAMMING
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