Basler Electric DECS-400 - Manual (Page 47)

9369700990 Rev R 35
AVR
AVR mode is selected by a momentary contact input applied to terminals B4 and B5. AVR mode may also
be selected through BESTCOMS. When operating in AVR mode, the DECS-400 adjusts the level of
excitation to maintain the desired generator terminal voltage level. The desired terminal voltage level is
entered (in primary generator voltage) through BESTCOMS or the front panel HMI as the AVR Setpoint
setting. The setting range of the AVR Setpoint depends on the generator ratings entered and the
minimum and maximum AVR settings. Once the AVR Setpoint is established, it can be fine tuned by
applying a contact input to terminals B7 and B8 (raise) or B8 and B9 (lower). Raise and lower inputs may
also be applied through BESTCOMS or Modbus. AVR Min and AVR Max settings control the range of
adjustment for the AVR setpoint. The AVR Min setting has a setting range of 70 to 100% of the rated
generator voltage and the AVR Max setting has a setting range of 100 to 110% of the rated generator
voltage. The length of time required to adjust the AVR setpoint from one limit to the other is controlled by
the AVR Traverse Rate setting. The AVR Traverse Rate is adjustable from 10 to 200 seconds.
Manual
Manual mode is selected by a momentary contact input applied to terminals B5 and B6. Manual mode
can also be selected through BESTCOMS. If enabled, Manual mode can be selected automatically when
a loss of sensing condition occurs. Manual mode can be configured through BESTCOMS to regulate
either the field current (FCR) or the field voltage (FVR).
FCR
When operating in FCR (field current regulation) mode, the DECS-400 adjusts the control output to
maintain the desired level of field current. The desired level of field current is entered through
BESTCOMS or the front panel HMI as the FCR Setpoint setting. The setting range of the FCR Setpoint
depends on the field type selected and other associated settings. Once the FCR setpoint is established, it
can be fine tuned by applying a contact input to terminals B7 and B8 (raise) or B8 and B9 (lower). Raise
and lower inputs may also be applied through BESTCOMS or Modbus. FCR Min and FCR Max settings
control the range of adjustment for the FCR setpoint. The FCR Min setting has a setting range of 0 to
100% of the rated field current and the FCR Max setting has a setting range of 0 to 120% of the rated
field current. The length of time required to adjust the FCR setpoint from one limit to the other is controlled
by the FCR Traverse Rate setting. The FCR Traverse Rate is adjustable from 10 to 200 seconds.
FVR
When operating in FVR (field voltage regulation) mode, the DECS-400 adjusts the control output to
maintain the desired level of field voltage. The desired level of field voltage is entered through
BESTCOMS or the front panel HMI as the FVR Setpoint setting. The setting range of the FVR Setpoint
depends on the field type selected and other associated settings. Once established, the FVR setpoint is
fine-tuned by applying a contact input to terminals B7 and B8 (raise) or B8 and B9 (lower). Raise and
lower inputs may also be applied through BESTCOMS or Modbus. FVR Min and FVR Max settings
control the range of adjustment for the FVR setpoint. The FVR Min and FVR Max settings have a setting
range of 0 to 150% of the rated field voltage. The length of time required to adjust the FVR setpoint from
one limit to the other is controlled by the FVR Traverse Rate setting. The FVR Traverse Rate is adjustable
from 10 to 200 seconds.
Var
Var mode is selected through BESTCOMS and enabled by a contact closure received at one of the
programmable contact inputs configured to enable Var/PF mode. When operating in Var mode, the
DECS-400 controls the reactive power (var) output of the generator. The desired var level, expressed in
kvar, is entered through BESTCOMS or the front panel HMI as the Var Setpoint setting. The setting range
of the Var Setpoint depends on the generator settings and the minimum and maximum var settings. Once
the var setpoint is established, it can be fine-tuned by applying a contact input to terminals B7 and B8
(raise) or B8 and B9 (lower). Raise and lower inputs may also be applied through BESTCOMS or
Modbus. The Var Min and Var Max settings control the range of adjustment for the var setpoint. The Var
Min setting has a setting range of –100 to 0% of the generator rated kVA output and the Var Max setting
has a setting range of 0 to 100% of the generator kVA output. The length of time required to adjust the
DECS-400 Functional Description