5–72
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
Note
The
RTD BIAS MINIMUM
,
RTD BIAS CENTER
, and
RTD BIAS MAXIMUM
setpoints is are seen
only if
ENABLE RTD BIASING
is set to “Yes”.
Note
The
STANDARD OVERLOAD CURVE NUMBER
is seen only if
SELECT CURVE STYLE
is set to
“Standard”. If the
SELECT CURVE STYLE
is set to “Voltage Dependent”, all setpoints shown
after the
STANDARD OVERLOAD CURVE NUMBER
are displayed. If the
SELECT CURVE STYLE
is
set to “Custom”, the setpoints shown after
TIME TO TRIP AT 20.0 X FLA
are not displayed.
The current measured at the output CTs is used for the thermal model. The thermal model
consists of five key elements: the overload curve and overload pickup level, the unbalance
biasing of the generator current while the machine is running, the cooling time constants,
and the biasing of the thermal model based on hot/cold generator information and
measured stator temperature. Each of these elements are described in detail in the
sections that follow.
MESSAGE
RTD BIAS CENTER
POINT: 130°C
Range: 0 to 250°C in steps of 1
MESSAGE
RTD BIAS
MAXIMUM: 155°C
Range: 0 to 250°C in steps of 1
MESSAGE
SELECT CURVE STYLE:
Standard
Range: Standard, Custom, Voltage
Dependent
MESSAGE
STANDARD OVERLOAD
CURVE NUMBER: 4
Range: 1 to 15 in steps of 1. See Note
below.
MESSAGE
TIME TO TRIP AT
1.01 x FLA: 17414.5 s
Range: 0.5 to 99999.9 in steps of 0.1.
See Notes below.
↓
MESSAGE
TIME TO TRIP AT
20.0 x FLA: 5.6 s
Range: 0.5 to 99999.9 in steps of 0.1.
See Notes below.
MESSAGE
MINIMUM ALLOWABLE
VOLTAGE: 80%
Range: 70 to 95% in steps of 1. See
Notes below.
MESSAGE
STALL CURRENT @ MIN
VOLTAGE: 4.80 x FLA
Range: 2.00 to 15.00
×
FLA in steps of
0.01. See Notes below.
MESSAGE
SAFE STALL TIME @
MIN VOLTAGE: 20.0 s
Range: 0.5 to 999.9 in steps of 0.1. See
Notes below.
MESSAGE
ACCEL. INTERSECT
@
MIN VOLT: 3.80 x FLA
Range: 2.00 to
STALL CURRENT @ MIN
VOLTAGE
in steps of 0.01. See
Notes below.
MESSAGE
STALL CURRENT @ 100%
VOLTAGE: 6.00 x FLA
Range: 2.00 to 15.00
×
FLA in steps of
0.01. See Note below.
MESSAGE
SAFE STALL TIME @
100% VOLTAGE: 10.0 s
Range: 0.5 to 999.9 in steps of 0.1. See
Notes below.
MESSAGE
ACCEL. INTERSECT @
100% VOLT: 5.00 x FLA
Range: 2.00 to
STALL CURRENT @ 100%
VOLTAGE
in steps of 0.01. See
Notes below.