Gard Marine occasionally receives reports of machinery failure due to overspeeding of the main engine or auxiliary engines. Any speed that exceeds the engine manufacturer’s operational range is considered overspeed. Overspeeding frequently causes major damage to the engine, as well as the generators and gears.
Overspeeding can be caused by a number of factors, the most prevalent of which are governor or fuel oil pump failure.
Because engine overspeed can cause damage to the crankshaft (push rod deformation), damaged valve seats, defective camshafts, turbocharger failure, and generator and gear failure, the repercussions can be severe.
Overspeed damage repair may necessitate the total dismantling and control of all critical engine components, which is both time-consuming and costly.
Overspeed protection for machinery must be tested according to the engine manual or the vessel’s maintenance system. Auxiliary engines can be examined without much effort on a regular basis, but main engines must usually be stopped during maritime journeys, which is inconvenient and costly. It may be necessary to postpone scheduled tests and/or maintenance as a result of this.
Overspeeding causes breakdowns, which are often costly to all parties concerned. It is necessary to follow the maintenance plan for critical parts such as speed governors, fuel pumps, and electrical and mechanical overspeed protection.
What could cause a generator to run at too high a speed?
Overspeed or the motion of a mechanical overspeed device actually occurred, making the overspeed shutdown line connected and causing the diesel engine to shut down; the second is the faults of the diesel engine as the prime mover; the third is the faults of the diesel engine as the prime mover; the fourth is the faults of the diesel engine as the prime mover; the fifth is the faults of the diesel engine as the prime mover; the sixth is the faults of the diesel engine as the prime mover; the
What is the definition of an overspeed fault?
- Instability or a high driving load. Usually caused by a load that causes the motor to spin quicker than the drive can keep up with.
- When the drive receives a run command, the motor may be spinning. Turn on the Catch-on-the-Fly feature.
How do you test a generator for an overspeed trip?
At no load, it can be tested by increasing the engine speed with the speed adjuster. At 115 percent of normal speed, an overspeed excursion will cut off the fuel supply.
What is a generator’s overspeed protection?
When the turbine generator’s speed exceeds a certain percentage of its rated speed, an overspeed protection system closes both the interceptor and governor valves and works with the main governor valve control system to release steam pressure in the reheating system.
What does the term “engine overspeed condition” refer to?
Engine Overspeed Condition (OBD Code P0219) Engine overspeed condition is defined by the trouble code P0219. This code indicates that the powertrain control module received a signal from the engine RPM sensor indicating that the vehicle’s engine has exceeded the maximum permissible limit.
What exactly is an overspeed excursion and how does it work?
An over speed trip is a safety measure installed on the ship’s diesel engine to prevent the engine from overheating and causing technical failure or unintended mishaps. An over speed trip is used in diesel engines to prevent the speed of the engine from exceeding the pre-set speed range.
The mechanical stress associated with the centripetal and centrifugal forces of the moving parts inside a Diesel engine is designed for a specific operational range. Because centripetal force is related to the square of rotational speed, stress rises fast as rotational speed rises. Excessive strains caused by increased operational speed can overwhelm mechanical connection strength. These can cause rotating parts to shatter or harm to the machinery itself. As a result, excessive speed is a severe safety danger that can result in a catastrophic situation.
The engine’s speed may vary due to rapid variations in the load on the diesel engine. Despite the presence of a governor to control the speed of the diesel engine, the speed may become out of control, causing damage to the engine. As a result, overspeed trips are employed.
The fundamental goal of an overspeed trip, regardless of the kind used by the engine, is to cut the fuel supply to the engine cylinders if the engine speed exceeds a certain threshold.
Reducing the chances of an uncontrollable and catastrophic overspeed is critical and can be accomplished in two ways:
A typical system layout is described below to help you comprehend the computerized overspeed trip. The electronic high-speed trip comprises of the following:
In generator engines, a magnetic speed sensor is preferred. Voltage is excited in the pick off coil of the sensor due to the discontinuity of the actuator surface (gear tooth of the flywheel), producing an electric analog wave. The sensor detects the cyclic wave created by the flywheel.
This gadget serves as a speed sensor receiver. The signal conditioner’s primary role is to convert one type of electrical signal into a more easily readable one. Amplification, excitation, and linearization of an electrical signal can be used to accomplish this.
This unit has a predefined value that is generally 10% higher than the rated speed and serves as the unit’s base value. The output of the signal condition unit is continuously monitored and compared to the set value.
If the difference between the set and detected values is greater than the limit, this device sends out a trip signal, which shuts down the generator.
What is the procedure for resetting a GE generator?
To re-set a Briggs or GE thermostat, follow these steps. Once the generator is turned off, look for the fuse under the controller’s flap, which will either be adjacent to or beneath the display screen and run the length of the controller. Replace the fuse in the slot after 30 seconds and press the manual button.