Underfrequency limiter – Basler Electric DECS-250N User Manual
Page 82
66
9440500990 Rev D
Limiters
DECS-250N
Figure 53. Limiter Scaling Settings
A
OEL and SCL Scale Enable: Select Auxiliary Input, AEM RTD 1 to AEM RTD 8, or Disabled.
B
Signal: Adjustable from –10 to +10 in 0.01 increments when Auxiliary Input is selected.
Adjustable from –58 to +482 in increments of 1 when any AEM RTD input is selected.
C
Scale: Adjustable from 0 to 200 in increments of 0.1.
Underfrequency Limiter
BESTCOMSPlus Navigation Path: Settings Explorer, Operating Settings, Limiters, Underfrequency
HMI Navigation Path: Settings, Operating Settings, Limiters, UEL
The underfrequency limiter is selectable for underfrequency limiting or volts per hertz limiting
A
. These
limiters protect the generator from damage due to excessive magnetic flux resulting from low frequency
and/or overvoltage.
Underfrequency and volts per hertz limiter settings are illustrated in Figure 56.
If the generator frequency decreases below the corner frequency
B
for the selected underfrequency slope
C
(Figure 54), the DECS-250N adjusts the voltage setpoint so that the generator voltage follows the
underfrequency slope. The adjustment range of the corner frequency and slope settings enables the
DECS-250N to precisely match the operating characteristics of the prime mover and the loads being
applied to the generator.