IS200VGENH1B

IS200VGENH1B is a Generator Monitor and Trip Board manufactured by and designed by General Electric as part of the Mark VI Series used in gas turbine control systems. The generator board VGEN and its terminal board TGEN track the voltage and currents in the generator's three phases and compute their power and power factor. Using fast-acting solenoids situated on the TRLY terminal board, VGEN performs the power load imbalance (PLU) and early valve actuation (EVA) duties for big steam turbine applications.

IS200VGENH1B Installation

Turn off the power to the VME I/O processor rack before installing the VGEN board. To seat, the edge connections on the VGEN board, slide it in and use your hands to push the top and bottom levers in. Next, tighten the front panel's captive screws at the top and bottom. These screws improve the board's front ground integrity and serve to firmly secure the board in place. The screws shouldn't be used to secure the board in place.

• The J3 connector on the lower part of the VME rack is used to connect the cable to the TGEN terminal board. To keep the cable in place, this connector latches.
• The J4 connector on the lower part of the VME rack is used to connect the cable to the optional TRLY terminal board. To keep the cable in place, this connector latches.
• Turn on the VME rack, then check the diagnostic lights at the top of the front panel.

Operation

• Three one-phase CT inputs and two three-phase PT inputs are monitored by VGEN. There are four analog inputs on TGEN, and they may be set to either 4-20 mA or 5, 10, or 20 V dc. The VGEN board converts signals and computes frequency, power, and power factor.
• VGEN provides the early valve actuation (EVA) and power load unbalances (PLU) capabilities for big steam turbines, as well as monitoring generator three-phase power. All three line-to-line voltages are calculated using three-wire, open delta voltage measurements from the generator and bus PT inputs. They are not utilized for automatic synchronization, which necessitates the use of two distinct single-phase PT inputs. The PTs are magnetically isolated, and each PT input has a nominal voltage of 115 V RMS.
• All PT and CT inputs have test points to enable field verification of the phase. Three single-phase CT inputs are offered, each with a standard continuous current range of 0 to 5 A. On TGEN, the Cts are magnetically isolated. The CTs' terminations consist of non-pluggable terminal blocks with captive lugs that can accommodate wires up to #10 AWG. These inputs are used to determine the following parameters:
• Total Mwatts
• Total Mvars
• Total MVA
• Power factor
• Bus frequency (5 to 66 Hz)


• The four analog inputs can take inputs of 4-20 mA or 5, 10, or 15 V dc. All four circuits have access to a +24 V dc source, and each circuit has its own current restriction. The +24 V dc supply from the turbine control or a self-powered source can be attached to the 4-20 mA transducer. On the terminal board, a jumper allows you to choose between each circuit's current and voltage inputs.

IS200VGENH1B Diagnostics

The VGEN front panel's three LEDs at the top display status data. A solid red indicates a failure, while a flashing green indicates a normal run. The third LED, which indicates STATUS, is typically off but will flash steadily orange in the event that the board has a diagnostic alert issue. The following is a list of the VGEN diagnostics:

• A high/low system (software) limit check and a high/low input signal (hardware) limit check are performed via diagnostics. In the field, the software limit check can be modified. For voltage inputs, open wire detection is offered, and relay drivers and coil currents are also tracked.
• The I/O board queries the connectors JR1, JS1, and JT1 on the terminal board, each of which has its own ID device. The terminal board serial number, board type, revision number, and plug location are all encoded on a read-only chip called the ID device.