Basler Electric DECS-250N - Manual (Page 62)

46 9440500990 Rev D
Protection DECS-250N
Figure 32. Underfrequency Protection Settings
A Underfrequency (81U) Pickup (Hz): Adjustable from 30 to 70 hertz in 0.01 hertz increments.
B Underfrequency (81U) Time Delay (s): Adjustable from 0.1 to 300 seconds in 0.1 second increments.
C Underfrequency (81U) Voltage Inhibit (%): Adjustable from 50 to 100% in 1% increments.
D Underfrequency (81U) Mode: Select Disable or Under.
Power Protection
BESTCOMSPlus Navigation Path: Settings Explorer, Protection, Power
HMI Navigation Path: Settings, Protection, Power
Generator power levels are monitored to protect against reverse power flow and loss of excitation.
Reverse Power
Reverse power protection guards against reverse power flow that may result from a loss of prime mover
torque (and lead to generator motoring). A reverse power condition occurs when the flow of reverse
power exceeds the 32R pickup threshold
A for the duration of the 32R time delay B . Reverse power
protection can be enabled and disabled C without altering the pickup and time delay settings. Reverse
power pickup and trip elements in BESTlogicPlus can be used in a logic scheme to initiate corrective
action in response to the condition. BESTCOMSPlus reverse power protection settings are illustrated in
Figure 33.
Figure 33. Reverse Power Protection Settings
A Reverse Power (32R) Pickup (%): Adjustable from 0 to 150% in 1% increments.
B Reverse Power (32R) Time Delay (s): Adjustable from 0 to 300 seconds in 0.1 second increments.
C Reverse Power (32R) Mode: Select Disabled or Enabled.
Loss of Excitation
The loss of excitation element operates on excessive var flow into the machine, indicating abnormally low
field excitation. This element protects controlled generators as well as motors. A diagram of the 40Q