DECS-200 Digital Excitation Control System
2
FEATURES, continued
DESCRIPTION
INPUTS
Control Power (style selectable)
16-60Vdc, Burden=30W.
85-132Vac, 50 or 60Hz, Burden=50VA. 90-150Vdc, Burden=30W.
AC Operating Power
1 or 3 Phase Power Input
DECS-200 Output
AC Voltage Nominal
Range (50-500Hz)
Burden
32Vdc
60Vac
56-70Vac ±10%
780VA
63Vdc
120Vac
100-139Vac ±10%
1570VA
125Vdc
240Vac
190-277Vac ±10%
3070VA
NOTES:
1)For applications that require the DECS-200 from a source that is already at the regulator's rated power input voltage level, an Inrush
Current Reduction Module is needed to minimize the amount of inrush current that may occur. Refer to Accessories (see page 11),
regarding ICRM-15.
2)To achieve the proper DECS-200 output voltage, the associated Operating Power must be provided. Min. voltage buildup: 3 Vac.
Generator Voltage Sensing
Single-phase or three-phase line voltage, four ranges:
• 100V/50Hz nominal (85 to 127V), 120V/60Hz nominal (94 to 153V)
• 200V/50Hz nominal (170 to 254V), 240V/60Hz nominal (187 to 305V)
• 400V/50Hz nominal (340 to 508V), 480V/60Hz nominal (374 to 600V)
• 500V/50Hz nominal (425 to 625V), 600V/60Hz nominal (510 to 660V)
Bus Voltage Sensing
Single-phase line voltage (AC), four ranges:
• 100V/50Hz nominal (85 to 127V), 120V/60Hz nominal (94 to 153V)
• 200V/50Hz nominal (170 to 254V), 240V/60Hz nominal (187 to 305V)
• 400V/50Hz nominal (340 to 508V), 480V/60Hz nominal (374 to 600V)
• 500V/50Hz nominal (425 to 625V), 600V/60Hz nominal (510 to 660V)
SPECIFICATIONS
The microprocessor based DECS-200 is a total excita-
tion control system in one enclosure. It contains all the
functionality necessary to limit, control, and protect a
generator from operating outside of the machine's
capability. A feature of DECS-200's sophisticated
design allows the nonactive control mode within the
unit to follow the active mode, permitting bumpless
transfer between modes. The optional external tracking
feature also allows for unit-to-unit communication,
permitting autofollowing and transfer between DECS-
200 units. It can also communicate to a PC via the front
panel RS-232 port for local programming and metering,
and it can communicate via Modbus™ protocol via the
side RS-485 port for communications up to 4000 feet
away from the DECS-200 unit. The DECS-200 has all
the features, functionality, flexibility and programmabil-
ity expected from a state-of-the-art microprocessor
based product.
• Voltage Matching
• Eight (8) generator protection features
• Programmable output contacts
• Front panel backlit LCD display
• Front panel mounted RS-232 and side RS-485
communications ports
• Modbus™ protocol for RS-485 input allows
communications up to 4000 feet away
• <1% metering accuracy for 12 generator parameters
• Remote set point control via:
- Contact inputs
- Proportional control via ±10Vdc or 4-20mA
- Communications inputs RS-232 (ASCII) or RS-485
(Modbus™)
• Meets C37.90.1-1989 for Surge Withstand and Fast
Transient
• UL recognized, CSA certified, CE compliant, DNV
certified, GOST-R certified, Byelorussian certified
• U.S. Patent Number 5,294,879
APPLICATIONS
The DECS-200 is an excitation control system used to control the output voltage, vars or power factor of a
synchronous generator by varying or controlling the amount of dc excitation applied to the generator's exciter
field. The DECS-200 is suitable for virtually any size machine.