DS215GGIAG1BZZ01A - Emergency Overspeed Protection Board

SPECIFICATIONS:

Part Number: DS215GGIAG1BZZ01A
Manufacturer: General Electric
Series: Mark V
Product Type: Emergency Overspeed Protection Board
Number of channels: 12
Input voltage: 125 - 400 VDC
Power Supply: 24V DC / 125V DC
Nominal power: up to 1000 W
Input Frequency Range: 0 Hz – 10 kHz
Input Voltage (MPU Sensors): 5V – 50V AC
Trip Relay Voltage: 24V DC / 125V DC
Input auxiliary voltage: up to 20 V DC
Operating Temperature: -20°C to +70°C
Vibration Resistance: 0.5g
Size: 8.25 cm high x 4.18 cm
Repair: 3-7 Day
Availability: In Stock
Weight: 2.5 Kg
Country of Origin: United States

FUNCTIONAL DESCRIPTION:

DS215GGIAG1BZZ01A is an Emergency Overspeed Protection Board manufactured and designed by General Electric as part of the Mark V Series used in GE Speedtronic Gas Turbine Control Systems. Its primary function is to monitor turbine speed and initiate an immediate shutdown in the event of an overspeed condition, preventing severe mechanical damage, catastrophic failure, and safety hazards. In gas turbines, speed control is essential for maintaining operational stability, and while the primary governor system regulates speed under normal conditions, the EOPB serves as an independent, fail-safe mechanism to ensure the turbine does not exceed safe operating limits.

The overspeed protection system is entirely independent of the primary control loop, allowing it to function even in the event of a failure in the Speedtronic control system. This redundancy enhances the reliability and safety of the gas turbine, ensuring compliance with industry safety standards such as API 612 and IEC 61508 for functional safety in rotating equipment.

INSTALLATION:

The process begins with the proper placement of Magnetic Pickup Units (MPUs), which are mounted near the turbine shaft to detect rotational speed. These sensors generate AC voltage signals proportional to the turbine’s speed, which are transmitted to the EOPB. To ensure accuracy and redundancy, at least three MPUs are typically installed, allowing the system to cross-verify readings and minimize the risk of false trips.

Once the MPUs are in place, the EOPB is mounted inside the turbine control panel, securely housed to protect it from environmental factors such as heat, vibration, and electromagnetic interference. Proper wiring is crucial for seamless communication between the MPUs, the board, and the trip relay system. The EOPB is connected to the fuel shutoff solenoid and hydraulic trip valves, which immediately stop fuel flow when an overspeed event is detected. Additionally, the system is programmed with a predefined overspeed trip threshold, typically set between 110% and 112% of the turbine’s rated speed, ensuring rapid response in the event of an anomaly.

After physical installation, a thorough testing and verification process is conducted. A frequency generator is often used to simulate various speed conditions, allowing engineers to confirm that the EOPB correctly detects overspeed events and triggers the trip mechanism within the required response time. This validation step ensures that the system functions correctly before commissioning the turbine for operational use. Proper documentation of the configuration settings, wiring, and test results is essential for future maintenance and troubleshooting.

OPERATION:

During normal turbine operation, the Emergency Overspeed Protection Board (EOPB) continuously monitors the turbine’s rotational speed using the real-time frequency signals received from the Magnetic Pickup Units (MPUs). These speed readings are processed through high-speed digital logic circuits, which compare the measured speed against the pre-configured overspeed setpoint. The system employs redundant channels to ensure that speed measurements are accurate and that false trips due to sensor noise or signal discrepancies are avoided.

If the turbine speed remains within the normal operating range, the EOPB remains in a passive state, allowing the primary speed control system to regulate the turbine’s performance. However, if an overspeed condition occurs—where the turbine speed exceeds the safe limit—the EOPB immediately initiates a trip sequence. This sequence involves sending a trip signal to the fuel shutoff solenoid, which rapidly cuts off the fuel supply to the turbine’s combustion chamber. Additionally, the system may engage hydraulic trip valves to further isolate fuel or steam flow, depending on the turbine type.

WOC maintains the largest inventory of Replacement parts for GE Speedtronic Gas Turbine Control Systems. Additionally, we offer warranty-backed unused and rebuilt boards as well as board repairs for your damaged ones. For your OEM needs, our team of professionals is available around the clock. We at WOC are happy to help you with any needs you may have in terms of automation. Please contact our team by phone or email for pricing and availability on any components and repairs.

FREQUENTLY ASKED QUESTIONS:

How does the Emergency Overspeed Protection Board detect overspeed conditions?

The EOPB detects overspeed conditions by continuously reading real-time speed signals from the Magnetic Pickup Units (MPUs) mounted near the turbine shaft. These MPUs generate AC voltage signals proportional to the shaft speed, which are converted into digital frequency values by the EOPB. The board then compares the measured frequency against the pre-set overspeed trip threshold, which typically ranges between 110% and 112% of the turbine’s rated speed.

What happens when an overspeed event is detected?

When an overspeed event is detected, the EOPB immediately sends a trip signal to shut down the turbine. This signal deactivates the fuel shutoff solenoid, cutting off the fuel supply to the combustion chamber, which rapidly stops the turbine. In some systems, the EOPB may also activate hydraulic trip valves to isolate fuel or steam flow further. The shutdown process occurs within milliseconds to prevent turbine damage.

How can operators reset the system after an overspeed trip?

After an overspeed trip, the system must be reset following a structured procedure to ensure that the root cause of the trip has been identified and resolved. Operators must first inspect speed sensor readings, trip logs, and system alarms to confirm whether the trip was valid or caused by a false signal. If an actual overspeed condition occurs, the turbine must be thoroughly checked for potential mechanical damage before restarting.