GE MI-869 Instruction Manual page 279

CHAPTER 4: SETPOINTS
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
MODE
Range: Definite Time, Adaptive
Default: Definite Time
The setting defines the operating mode of the Acceleration Time element. When set to
"Definite Time", the element times duration of the motor start and operates when the
starting time exceeds the acceleration Time setting. When set to "Adaptive", the element
uses the effective accelerating current to adapt to the starting conditions. The operating
equation assumes that the accelerating power is proportional to the square of the
current and neglects any current unbalance or impact of the rotor slip. Consequently, in
the Adaptive mode, the element operates when the square of the current integrated
from the beginning of the start up to a given time exceeds the product of acceleration
2
Current x Time.
OUTPUT RELAY X
Range: Do Not Operate, Operate
Default: Do Not Operate
Any assignable output relay can be selected to operate upon Acceleration Time
operation.
BLOCK
Range: FlexLogic Operand
Defatul: Off
The Acceleration Time element can be blocked by any asserted FlexLogic operand.
EVENTS
Range: Enabled, Disabled
Default: Enabled
TARGETS
Range: Self-reset, Disabled
Default: Latched
PROTECTION
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