GE Multilin 745

S2 System Setup
745
Transformer Management Relay
Setpoints
http://www.GEindustrial.com/multilin
5–31
GE Multilin
• 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 current 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 derating factor, and in the Insulating Aging
function. This is an auto-ranging setpoint dependent on the
LOW VOLTAGE
WINDING 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 accumulated 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 kV
in steps of 0.1
0.01 to 200.00 kV
in steps of 0.01
0.001 to 20.000
kV
in steps of 0.001
VOLTAGE
INCREMENT PER TAP
0.01 to 20.00 kV
in steps of 0.01
0.001 to 2.000 kV
in steps of 0.001
0.0001 to 0.2000
kV in steps of
0.0001
LOAD LOSS AT RATED
LOAD
1 to 20000 kW
in steps of 0.1
0.1 to 2000.0 kW
in steps of 0.01
0.01 to 200.00 kW
in steps of 0.001
NO LOAD LOSS
0.1 to 2000.0 kW
in steps of 1
0.01 to 200.00 kW
in steps of 0.1
0.001 to 20.000
kW in steps of
0.01
WARNIN
G
3
3