GE 845 - Page 371

CHAPTER 4: SETPOINTS MONITORING
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 4–243
to measure Ambient temperature, select the “Monthly Average” setting, and enter the
approximate average temperature per month in the monthly calendar menu. If Top-
Oil temperature measurement is not available, select the setting “Computed”.
NOTE
NOTE:
To change the temperature unit, i.e. Fahrenheit, Celsius go to Setpoints > Device > Front
Panel menu.
The inputs for Ambient Temperature and Top-Oil Temperature from Thermal Inputs menu
include selection of RTDs. The selected RTDs must be programmed, for the temperature to
be measured on the relay and be included in the calculation for hottest-spot winding
temperature.
Winding Currents CT Bank 1-J1
Ambient Temperature Monthly Average
January -20 ° C
February -20 ° C
March -20 ° C
April 7 ° C
May 15 ° C
June 25 ° C
July 30 ° C
August 30 ° C
September 20 ° C
October 17 ° C
November 14 ° C
December 9 ° C
Top-Oil Temperature Computed
..\System\Transformer\Thermal Inputs
Setpoints Value Unit
<<
Status Tap Chan
Thermal
Function Disabled
Name RTD 1
Type 100 W Platinum
Trip Temperature 155 º C
Trip Pickup Delay 2 s
Trip Dropout Delay 0 s
Trip Output Relay X Do Not Operate
Alarm Function Disabled
Alarm Temperature 130 º C
Alarm Pickup Delay 2 s
Alarm Dropout Delay 0 s
Alarm Output Relay X Do Not Operate
Sensor Open None
Block Off
Events Enabled
Targets Latched
..\Setpoints\RTD Temperature\RTD 1
Setpoints Value Unit
RTD 1
RTD 2 RTD 4
>>RTD 3