GE TRANSFORMER MANAGEMENT RELAY 745 Instruction Manual page 133

5 SETPOINTS
d) LOSS OF LIFE LIMIT
PATH: SETPOINTS S4 ELEMENTS
LOSS OF LIFE LIMIT
[ENTER] for more
The Loss of Life Limit element computes the total expended life of the transformer, based on the aging factor and the actual
in-service time of the transformer. For example, if the aging factor is a steady 1.5 over a time period of 10 hours, the trans-
former will have aged for an equivalent 1.5
the relay even when control power is lost. The initial Loss of Life value, when a relay is first placed in service, can be pro-
grammed under the transformer settings. The element operates on the cumulative total value, with no time delay. The out-
put of this element should be used as an alarm only, as users may wish to leave the transformer in service beyond the
theoretical expended life.
Enter the expended life, in hours, required for operation of the element in the
should be above the total life of the transformer, in hours. As an example, for a 15-year transformer, the total number of
hours would be 13140
×
The actual values are only displayed if the Loss of Life option is installed and the ambient temperature is
enabled.
NOTE
GE Multilin
Courtesy of NationalSwitchgear.com
INSULATION AGING
ð
LOSS OF LIFE LIMIT
ENTER
FUNCTION: Disabled
ESCAPE
LOSS OF LIFE LIMIT
ESCAPE
TARGET: Self-Reset
MESSAGE
LOSS OF LIFE LIMIT
ESCAPE
PICKUP: 16000 x 10h
MESSAGE
LOSS OF LIFE LIMIT
ESCAPE
BLOCK: Disabled
MESSAGE
10 = 15 hours. The cumulative total number of hours expended is retained in
×
10 = 131400.
Figure 5–38: LOSS-OF-LIFE SCHEME LOGIC
745 Transformer Management Relay
LOSS OF LIFE LIMIT
Range: Enabled, Disabled
Range: Self-Reset, Latched, None
Range: 0 to 20000 x 10h (providing for a maximum of
20000 hours) in steps of 1
Range: Logc Inpt 1 to 16, Virt Inpt 1 to 16, Output Rly 2 to
8, SelfTest Rly, Vir Outpt 1 to 5, Disabled
LOSS OF LIFE PICKUP
5.6 S4 ELEMENTS
setpoint. This setting
5
5-83