GE 845 Instruction Manual page 376

MONITORING
Loss of Xfmr Life
4–248
The Loss of Life (LOL) element provides a mechanism for detecting the accumulated total
consumed transformer life. It can be set to issue an alarm or trip, when the actual
accumulated transformer loss of life is higher than what is specified by the user loss of life
pickup setpoint. For brand new installed transformers, the setting for "XFMR INITIAL LOSS"
is "0", and for already installed transformers, the user must estimate the consumed
transformer life in hours, being in service.
Path:
Setpoints > Grouped Elements > Setting Group 1(8) > Transformer > Loss of Xfmr Life
FUNCTION
Range: Disabled, Alarm, Latched Alarm, Configurable
Default: Disabled
INITIAL XFMR LOL
Range: 1 to 500000 hours in steps of 1 hr
Default: 0 hours
Enter a setting for the consumed transformer life in hours. When the LOL element is
enabled, the loss of life computed by the relay is added to the initial loss of life in hours.
PICKUP
Range: 0 to 500000 hours in steps of 1 hr
Default: 200000 hours
Enter the expected life, in hours, required for operation of the element. This setting must
be above the total transformer life set as a reference based on nominal loading
conditions, and 30º C ambient temperature, as outlined in the IEEE standards.
BLOCK
Range: Off, Any FlexLogic operand
Default: Off
The Neutral IOC is blocked when the selected operand is asserted.
OUTPUT RELAY 1(X)
Range: Do Not Operate, Operate
Default: Do Not Operate
The menu includes a list of available output relays to be set for operation or no
operation upon protection operation.
EVENTS
Range: Enabled, Disabled
Default: Enabled
The selection of the
Enabled
TARGETS
Range: Disabled, Self-reset, Latched
Default: Self-reset
The selection of the Self-reset
function.
Figure 4-96: Loss of Life Logic diagram
setting enables the Events function.
or Latched settings enables the target messages of the
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS