GE L30 Instruction Manual page 372

GROUPED ELEMENTS
5.7.4 Phase current
5.7.4.1 Menu
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  PHASE CURRENT
 PHASE CURRENT

5
5.7.4.2 Inverse TOC curve characteristics
The inverse time overcurrent curves used by the time overcurrent elements are the IEEE, IEC, GE Type IAC, and I
curve shapes. This allows for simplified coordination with downstream devices.
If none of these curve shapes is adequate, FlexCurves can be used to customize the inverse time curve characteristics. The
definite time curve is also an option that can be appropriate if only simple protection is required.
Table 5-27: Overcurrent curve types
IEEE
IEEE Extremely Inverse
IEEE Very Inverse
IEEE Moderately Inverse
A time dial multiplier setting allows selection of a multiple of the base curve shape (where the time dial multiplier = 1) with
the curve shape (
CURVE
to the time multiplier (
or base curve values. Setting the multiplier to zero results in an instantaneous response to all current levels above pickup.
5-194
Figure 5-96: Stub bus logic
 PHASE TOC 1


 PHASE TOC 2


 PHASE IOC 1


 PHASE IOC 4


 PHASE

 DIRECTIONAL 1
 PHASE

 DIRECTIONAL 2
IEC
IEC Curve A (BS142)
IEC Curve B (BS142)
IEC Curve C (BS142)
IEC Short Inverse
) setting. Unlike the electromechanical time dial equivalent, operate times are directly proportional
) setting value. For example, all times for a multiplier of 10 are 10 times the multiplier 1
TD MULTIPLIER
See page 5-200
See page 5-202

See page 5-203
GE type IAC
IAC Extremely Inverse
IAC Very Inverse
IAC Inverse
IAC Short Inverse
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
2
t standard
Other
2
I t
FlexCurves A, B, C, and D
Recloser Curves
Definite Time