5-30
745 Transformer Management Relay
GE Multilin
5.4 S2 SYSTEM SETUP
5 SETPOINTS
5
•
TRANSFORMER TYPE
: Enter the transformer connection from the table of transformer types. Phase correction and
zero-sequence removal are performed automatically as required.
If
TRANSFORMER TYPE
is entered as “2W External Correction” or 3W External Correction” with a Delta/Wye
power transformer, the
WINDING 1(3) PHASE CT PRIMARY
setting values must be divided by
on the Delta cur-
rent transformer side to compensate the current magnitude. With this correction, the 745 will properly compare
line to neutral currents on all sides of the power transformer.
For example, for a 2-Winding Delta/Wye power transformer with Wye connected current transformers on the
Delta side of the power transformer (25000:5 ratio), and Delta connected current transformers on the Wye side
of the power transformer (4000:5 ratio), set:
TRANSFORMER TYPE
= "
2W External Connection"
WINDING 1 PHASE CT PRIMARY
=
"25000:5"
WINDING 2 PHASE CT PRIMARY
=
(4000 /
):5 or "2309:5"
•
LOAD LOSS AT RATED LOAD
: Enter the load loss at rated load. This value is used for calculation of harmonic derat-
ing factor, and in the Insulating Aging function. This is an auto-ranging setpoint dependent on the
LOW VOLTAGE WIND-
ING RATING
value; see ranges in the following table
•
LOW VOLTAGE WINDING RATING
: Enter the low voltage winding rating. This selection affects the ranges of
WINDING
1(3) NOM Ø-Ø VOLTAGE
,
WINDING 1(3) RATED LOAD
,
MINIMUM TAP POSITION VOLTAGE
, and
VOLTAGE INCREMENT PER TAP
as
shown in the table above.
•
RATED WINDING TEMP RISE
: Determines the type of insulation; for use in the computation of Insulation Aging.
•
NO LOAD LOSS
: From the transformer data. It is required for Insulation Aging calculations This is an auto-ranging
setpoint dependent on the
LOW VOLTAGE WINDING RATING
value; see ranges in the above table.
•
TYPE OF COOLING
: From Transformer data; required for Insulation Aging calculations.
•
RATED TOP OIL RISE OVER AMBIENT
: Required for Insulation Aging calculations
•
XFMR THRML CAPACITY
: Required for Insulation Aging calculations. Obtain from transformer manufacturer
•
WINDING TIME CONST
: Required for Insulation Aging calculations
•
SET ACCUMULATED LOSS OF LIFE
: Required for Insulation Aging calculations. Set equal to the estimated accumu-
lated loss of life.
SETTING
LOW VOLTAGE WINDING RATING
ABOVE 5 KV
1 KV TO 5 KV
BELOW 1 KV
MINIMUM TAP POSITION VOLTAGE
0.1 to 2000.0
in steps of 0.1 kV
0.01 to 200.00
in steps of 0.01 kV
0.001 to 20.000
in steps of 0.001 kV
VOLTAGE INCREMENT PER TAP
0.01 to 20.00
in steps of 0.01 kV
0.001 to 2.000
in steps of 0.001 kV
0.0001 to 0.2000
in steps of 0.0001 kV
LOAD LOSS AT RATED LOAD
1 to 20000
in steps of 0.1 kW
0.1 to 2000.0
in steps of 0.01 kW
0.01 to 200.00
in steps of 0.001 kW
NO LOAD LOSS
0.1 to 2000.0
in steps of 1 kW
0.01 to 200.00
in steps of 0.1 kW
0.001 to 20.000
in steps of 0.01 kW
WARNING
3
3
