9440300990 Rev J
43
DECS-250
Protection
Figure 27. Overexcitation Protection Settings
A
Definite Time Pickup
: Adjustable from 0 or 0.5 to 6.00 in increments of 0.01.
B
Definite Time Delay
: Adjustable from 0.05 to 600 seconds in increments of 0.001 seconds.
C
Inverse Time Pickup
: Adjustable from 0 or 0.5 to 6.00 in increments of 0.01.
D
Time Dial
: Adjustable from 0.0 to 9.9 in increments of 0.1.
E
Reset Dial
: Adjustable from 0.0 to 9.9 in increments of 0.1.
F
Mode
: Select Enabled or Disabled.
G
Curve Exponent
: Select 0.5, 1, or 2
Generator Undervoltage
An undervoltage pickup condition occurs when the sensed generator terminal voltage decreases below
the pickup setting
A
. An undervoltage trip condition occurs if the generator voltage remains below the
pickup threshold for the duration of the time delay setting
B
. Generator undervoltage protection can be
enabled and disabled
C
without altering the pickup and time delay settings. Undervoltage 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
®
generator undervoltage settings are illustrated in Figure 28.
Figure 28. Generator Undervoltage Protection Settings
A
Generator Undervoltage Pickup (V)
: Adjustable from 0 to 600,000 Vac in 1 Vac increments.
B
Generator Undervoltage Time Delay (s)
: Adjustable from 0.1 to 60 seconds in 0.1 second increments.
C
Generator Undervoltage Enable/Disable
: Select Enabled or Disabled.
Summary of Contents for DECS-250
Page 2: ......
Page 6: ...iv 9440300990 Rev J Revision History DECS 250 ...
Page 16: ...xiv 9440300990 Rev J Contents DECS 250 ...
Page 20: ...4 9440300990 Rev J Introduction DECS 250 ...
Page 28: ...12 9440300990 Rev J Power Stage DECS 250 ...
Page 32: ...16 9440300990 Rev J Voltage and Current Sensing DECS 250 ...
Page 40: ...24 9440300990 Rev J Synchronizer DECS 250 ...
Page 52: ...36 9440300990 Rev J Auxiliary Control DECS 250 ...
Page 56: ...40 9440300990 Rev J Contact Inputs and Outputs DECS 250 ...
Page 84: ...68 9440300990 Rev J Limiters DECS 250 ...
Page 114: ...98 9440300990 Rev J Power System Stabilizer DECS 250 Figure 96 PSS Parameter Settings ...
Page 124: ...108 9440300990 Rev J Stability Tuning DECS 250 ...
Page 126: ...110 9440300990 Rev J Mounting DECS 250 Figure 103 Overall and Projection Mounting Dimensions ...
Page 127: ...9440300990 Rev J 111 DECS 250 Mounting Figure 104 DECS 250 Escutcheon Plate Dimensions ...
Page 198: ...182 9440300990 Rev J Timekeeping DECS 250 ...
Page 210: ...194 9440300990 Rev J CAN Communication DECS 250 ...
Page 304: ...288 9440300990 Rev J Maintenance DECS 250 ...
Page 316: ...300 9440300990 Rev J Specifications DECS 250 ...
Page 334: ...318 9440300990 Rev J Analog Expansion Module DECS 250 ...
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