50
9440300990 Rev J
Protection
DECS-250
Where:
Time
reset
= maximum time to reset in seconds
TD
= time dial setting <0.1, 20>
MOP
reset
= multiple of pickup <1.03, 205>
Primary and secondary setting groups provide additional control for two distinct machine operating
conditions.
Field overcurrent protection can be enabled and disabled
E
without altering the pickup and time delay
settings. Field overcurrent pickup and trip elements in BESTlogic
Plus
can be used in a logic scheme to
initiate corrective action in response to the condition. BESTCOMS
Plus
field overcurrent settings are
illustrated in
Figure 37. In BESTCOMS
Plus,
a plot of the field overcurrent setting curve is displayed. The
plot can display the primary or secondary setting curves.
Figure 37. Field Overcurrent Protection Settings
A
Field Overcurrent Pickup (A)
: Adjustable from 0 to 22 Adc in 0.1 Adc increments.
B
Timing Mode:
Select Definite Timing or Inverse Timing
C
Field Overcurrent Time Delay (s)
: Adjustable from 0 or 5 to 60 seconds in 0.1 second increments.
D
Field Overcurrent Time Dial:
Adjustable from 0.1 to 20 in increments of 0.1.
E
Field Overcurrent Mode
: Select Disabled or Enabled.
F
Inverse field overcurrent pickup curve.
G
Curve display selections.
Exciter Diode Monitor
The exciter diode monitor (EDM) monitors the condition of a brushless exciter’s power semiconductors by
monitoring the exciter field current. The EDM detects both open and shorted rotating diodes in the exciter
bridge. EDM settings are illustrated in Figure 38. When implementing the EDM, it is imperative that the
user know and specify the number of poles for the exciter armature and the generator rotor. For reliable
open diode detection, the exciter to generator pole ratio
A
should be 1.5 or higher and the level of field
current should be no less than 1.5 Adc. A pole ratio calculator, available in BESTCOMS
Plus,
can be used
to calculate the pole ratio from the number of exciter armature and generator rotor poles.
Содержание DECS-250
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Страница 16: ...xiv 9440300990 Rev J Contents DECS 250 ...
Страница 20: ...4 9440300990 Rev J Introduction DECS 250 ...
Страница 28: ...12 9440300990 Rev J Power Stage DECS 250 ...
Страница 32: ...16 9440300990 Rev J Voltage and Current Sensing DECS 250 ...
Страница 40: ...24 9440300990 Rev J Synchronizer DECS 250 ...
Страница 52: ...36 9440300990 Rev J Auxiliary Control DECS 250 ...
Страница 56: ...40 9440300990 Rev J Contact Inputs and Outputs DECS 250 ...
Страница 84: ...68 9440300990 Rev J Limiters DECS 250 ...
Страница 108: ...92 9440300990 Rev J Power System Stabilizer DECS 250 Figure 85 PSS Function Blocks and Software Switches ...
Страница 114: ...98 9440300990 Rev J Power System Stabilizer DECS 250 Figure 96 PSS Parameter Settings ...
Страница 124: ...108 9440300990 Rev J Stability Tuning DECS 250 ...
Страница 126: ...110 9440300990 Rev J Mounting DECS 250 Figure 103 Overall and Projection Mounting Dimensions ...
Страница 127: ...9440300990 Rev J 111 DECS 250 Mounting Figure 104 DECS 250 Escutcheon Plate Dimensions ...
Страница 128: ...112 9440300990 Rev J Mounting DECS 250 Figure 105 Panel Cutting and Drilling Dimensions for DECS 250 Panel Mounting ...
Страница 198: ...182 9440300990 Rev J Timekeeping DECS 250 ...
Страница 210: ...194 9440300990 Rev J CAN Communication DECS 250 ...
Страница 304: ...288 9440300990 Rev J Maintenance DECS 250 ...
Страница 316: ...300 9440300990 Rev J Specifications DECS 250 ...
Страница 334: ...318 9440300990 Rev J Analog Expansion Module DECS 250 ...
Страница 341: ...9440300990 Rev J 325 DECS 250 Contact Expansion Module Figure 188 CEM 2020 Input Contact and Output Contact Terminals ...
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