GE L90 Instruction Manual page 160

5.2 PRODUCT SETUP
components. The cut-off operation applies to quantities used for metering, protection, and control, as well as those
used by communications protocols. Raw samples of the voltages available via oscillography are not subject cut-off.
The
CURRENT CUT-OFF LEVEL
power cut-off level is calculated as shown below. For Delta connections:
3-phase power cut-off
For Wye connections:
3-phase power cut-off
per-phase power cut-off
where VT primary = VT secondary
For example, given the following settings:
CURRENT CUT-OFF LEVEL
VOLTAGE CUT-OFF LEVEL
PHASE CT PRIMARY
PHASE VT SECONDARY
: "208.00 : 1"
PHASE VT RATIO
PHASE VT CONNECTION
We have:
5
CT primary = "100 A", and
VT primary =
PHASE VT SECONDARY
The power cut-off is therefore:
power cut-off = (
CURRENT CUT-OFF LEVEL
= (
= 720.5 watts
Any calculated power value below this cut-off will not be displayed. As well, the three-phase energy data will not accumu-
late if the total power from all three phases does not exceed the power cut-off.
Lower the
VOLTAGE CUT-OFF LEVEL
as valid measurements. Unless dictated otherwise by a specific application, the default settings of "0.02
pu" for
NOTE
CURRENT CUT-OFF LEVEL
PATH: SETTINGS PRODUCT SETUP
CLEAR RELAY
RECORDS
5-14
and the
VOLTAGE CUT-OFF LEVEL
3
CURRENT CUT-OFF LEVEL
= ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
3
CURRENT CUT-OFF LEVEL
=
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
CURRENT CUT-OFF LEVEL
= ------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------- -
VT ratio and CT primary = CT secondary
: "0.02 pu"
: "1.0 V"
: "100 A"
: "66.4 V"
: "Delta".
x
PHASE VT RATIO
VOLTAGE CUT-OFF LEVEL
3 0.02 pu 1.0 V 100 A
and
CURRENT CUT-OFF LEVEL
and "1.0 V" for
CLEAR RELAY RECORDS
CLEAR FAULT REPORTS:
Off
CLEAR EVENT RECORDS:
MESSAGE
Off
CLEAR OSCILLOGRAPHY?
MESSAGE
No
CLEAR DATA LOGGER:
MESSAGE
Off
CLEAR ARC AMPS 1:
MESSAGE
Off
CLEAR ARC AMPS 2:
MESSAGE
Off
L90 Line Current Differential System
are used to determine the metered power cut-off levels. The
VOLTAGE CUT-OFF LEVEL
VT secondary
VOLTAGE CUT-OFF LEVEL
VT secondary
VOLTAGE CUT-OFF LEVEL
VT secondary
CT ratio.
= 66.4 V x 208 = 13811.2 V
CT primary
13811.2 V) / 66.4 V
with care as the relay accepts lower signals
VOLTAGE CUT-OFF LEVEL
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: FlexLogic™ operand
Range: FlexLogic™ operand
5 SETTINGS
VT primary CT primary
VT primary CT primary
VT primary CT primary
VT primary)/VT secondary
are recommended.
5.2.3 CLEAR RELAY RECORDS
(EQ 5.3)
(EQ 5.4)
(EQ 5.5)
GE Multilin