GE F60 Instruction Manual page 98

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 × VT ratio and CT primary = CT secondary × CT ratio.
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
5-10
and the
VOLTAGE CUT-OFF LEVEL
×
3
CURRENT CUT-OFF LEVEL
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
=
×
3
CURRENT CUT-OFF LEVEL
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
=
CURRENT CUT-OFF LEVEL
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
=
: "0.02 pu"
: "1.0 V"
: "100 A"
: "66.4 V"
: "Delta".
x
PHASE VT RATIO
×
VOLTAGE CUT-OFF LEVEL
× 0.02 pu × 1.0 V × 100 A × 13811.2 V) / 66.4 V
3
and
CURRENT CUT-OFF LEVEL
and "1.0 V" for
F60 Feeder Management Relay
are used to determine the metered power cut-off levels. The
× ×
VOLTAGE CUT-OFF LEVEL
VT secondary
× ×
VOLTAGE CUT-OFF LEVEL
VT secondary
× ×
VT primary
VOLTAGE CUT-OFF LEVEL
VT secondary
= 66.4 V x 208 = 13811.2 V
× CT primary × VT primary)/VT secondary
with care as the relay accepts lower signals
are recommended.
VOLTAGE CUT-OFF LEVEL
5 SETTINGS
×
VT primary CT primary
(EQ 5.3)
×
VT primary CT primary
(EQ 5.4)
×
CT primary
(EQ 5.5)
GE Multilin