Voltage Sensing - GE 469 Instruction Manual

4 SETPOINTS
PHASE CT PRIMARY:
MOTOR FULL LOAD AMPS:
5 A Secondary"
GROUND CT:
GROUND CT PRIMARY:
Example 2:
Consider a 469 with a 5 A Phase CT secondary and Ground Fault Detection set to Residual and a motor with the following
specifications:
Motor Nameplate FLA: 255 A; Solidly Grounded; Maximum Fault: 10000 A;
Zero Sequence Ground CT: (10000/20) 500:1
The following settings are required:
"300"
PHASE CT PRIMARY
MOTOR FULL LOAD AMPS
"5 A Secondary"
GROUND CT
GROUND CT PRIMARY
Example 3:
Again, consider a 469 with a 5 A Phase CT secondary and Ground Fault Detection set to Residual and a motor with the fol-
lowing specifications:
Motor Nameplate FLA: 330 A; High Resistance Grounded; Maximum Fault: 5 A
The following settings are required:
350"
PHASE CT PRIMARY
MOTOR FULL LOAD AMPS
"Multilin 50:0.025"
GROUND CT:
Õ×
PATH: SETPOINTS S2 SYSTEM SETUP
n VOLTAGE SENSING
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The manner in which the voltage transformers are connected must be entered here. A value of "None" indicates that no
voltage measurement is required. Note that phase reversal is disabled for single VT operation. All voltages are assumed
balanced. Also, frequency is only available for AN or AB connections.
If voltage measurements are to be made, the turns ratio of the voltage transformers must be entered. The
must be chosen such that the secondary voltage of the VTs is between 40 and 240 V when the primary is at
FORMER RATIO
MOTOR NAMEPLATE VOLTAGE
the
MOTOR NAMEPLATE VOLTAGE
line to line.
For example, given the following specifications: the Motor Nameplate Voltage is 4160 V, the VTs are 4160/120 Open Delta.
Set the Voltage Sensing setpoints as follows:
VT CONNECTION TYPE:
"34.67:1"
VT RATIO:
MOTOR NAMEPLATE VOLTAGE:
GE Multilin
Courtesy of NationalSwitchgear.com
"100"
"87"
"100"
255"
"500"
"330"
Õ×

VOLTAGE SENSING

ð
VT CONNECTION TYPE:
ENTER
ESCAPE None
ENABLE SINGLE VT
ESCAPE
OPERATION: OFF
MESSAGE
VOLTAGE TRANSFORMER
ESCAPE
RATIO: 35.00:1
MESSAGE
MOTOR NAMEPLATE
ESCAPE
VOLTAGE: 4000 V
MESSAGE
. All voltage protection features that require a level setpoint are programmed as a percent of
or rated voltage, where
"Open Delta"
"4160"
469 Motor Management Relay
Range: Open Delta, Wye, None
Range: AN, BN, CN, OFF or AB, CB, OFF. Seen only if
VT Connection Type is Wye or Open Delta
Range: 1.00:1 to 300.00:1 in steps of 0.01
Range: 100 to 36000 V in steps of 1
MOTOR NAMEPLATE VOLTAGE
4.3 S2 SYSTEM SETUP
4.3.2 VOLTAGE SENSING
VOLTAGE TRANS-
represents the rated design voltage
4
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