In what scenario would an EDG fail to start in an actual emergency but still be able pass a routine test? Both before and after the actual failure?
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For example say the EDG on the Dali was tested now and it started just fine.
Is there some possible explanation, maybe involving terms such as “3-phase” or "power factor’ (to pull a couple terms out of thin air) that might cause the EDG not to detect the power failure.
There is also the matter of the quick closing valve.
Not sure if this meets your definition of “correctly configured” but … during a typical Flag/PSC inspection for example the quick closing valve is tested using the remote closing mechanism located outside the space and then reset. If this is done after starting/testing the generator and everyone leaves it is possible the quick closing valve actually remains closed instead of open. The EDG would start in an emergency but would die out in less than a minute, probably a few seconds. It is probable that it would not run long enough to connect to the emergency bus.
As a best practice, the quick closing valve should always be tested BEFORE the generator so the running of the generator serves as evidence of the correct setting of the quick closing valve.
I’m not familiar with the automation of their power management system but I don’t think they ever had to go to EDG power.
I’m Chief Eng of a modern Chinese built US flagged Tanker that was built for to class LR standards.
I have 4 AE’s on my ship. I had a very similar power failure a few months ago where I had went to put a second generator online in preparation for arrival and when the breaker for the oncoming generator attempted to close it failed to close. At the same time the inline generator tripped on high voltage we went over 490v on a 450v bus.
When this happened I had a total power failure and lost the plant just like the Dali did. My EDG started but I was able to manually close the breaker to the generator that I still had running that had failed to close. We had to go and close all of our under-voltage trips on the switchboard as well as through out the plant. Because we were making way and underway the engine was very easy to restart once we cleared the EOT alarms.
We never went on EDG power but it did start and idle, then started its cool down procedure and returned to standby status on its own.
Hope this helps.
Interesting incident escalation on failure of the emergency power. Late 90s one of our large post-panamax container vessels experienced really heavy weather and rolling with lashings giving way with containers overboard and stacks of containers dangerously tilted/slanted on deck.
Engine room personnel were on standby as the Master was trying his best on the Bridge. All of a sudden the emergency bus-tie breaker opens. And the EDG power does come on line. When they go upto the EDG space they see about a foot of water sloshing around. Location is main deck. Auto ventilation louvers for combustion air/cooling are required to be provided was open allowing green water ingress. (You also have ventilation louvers in front of the large radiator that opens during start up of the EDG). No drain in the space and the crew get to de-watering the space asap. So remember at this time, all the emergency services are inoperative. Back in the engine room, after about an hour or so out of the blue the essential generator stops. Totally dark. Somehow the engineers figured out it must be the 24V battery system that provides power to the safety system on the DGs must have drained out. With some temporary overrides, they manage to get the generator started and also provide temporary 220V to the battery charger. And the main engine as well. Couple of hours later, EDG room was dried out and switchboard restored. Quite a bit of the damage to the lashings/deck containers was during the blackout period.
Everybody onboard were really shaken up. The fallen containers damaged some of the fire hydrants on deck and thus no fire water fighting capability. The crew was so shaken up and it was a really a task to make them understand that it was a USCG requirement to get the integrity of fire main to be allowed to come in. Had to insert spade blanks on the fire main in the box girders and finally the vessel came to PNW.
On attending the vessel, turned out the bypass for the ventilation louvers of all places in the CCR was kept open since delivery as the space was getting too hot. We also corrected the battery charger issue by providing a secondary means from the main switchboard. Quite a bit of interviews and questioning of both the Chief and Master by the authorities. Both advised they had no desire to return to sea anytime soon.
That sounds similar to one of the first blackouts I experienced. Each week we would swap over the 24v battery charger between banks, and also swap which battery bank was feeding 24v to the mains and generator controls system, including the electronic governors. But one week the Ch Elec swapped the charger but not the feeder breaker, so the charger was charging the offline battery bank, and the online battery bank slowly drained down over the course of a day. Error Chain: the 24v low-voltage alarm buzzer in the control room didn’t work and no one was aware. Mid next day we lost the plant as the governors lost power, generators slowed down and tripped on undervoltage. EDG started, and it fed the emergency bus, and the bus fed the battery charger, but that was feeding a battery bank that was offline. Someone had to run up six decks to the emergency generator room to swap the battery bank switch over. If we were heading for a bridge we would have hit it.
I’ve also been on a ship that was held in port after we did a regular black-start test of the EDG and it failed. We manually tripped the bus-tie, EDG started, but EDG breaker failed to close due to a mechanical piece in the spring mechanism failing. Worked every time prior, until it didn’t.
Different black out scenario, I’ve had one of those simple voltage sensing dead-bus relays fail on a standby generator. The relays were there so that if a generator started as a result of a blackout and the bus was dead it would just close the breaker immediately since there was no need to synchronize with another generator. We had two generators online and auto-started the third. Since that generator’s relay had failed it’s breaker logic system took that to mean the main bus was dead and it tried to close the breaker without synchronizing. It tried closing 180-deg out of phase, smoked the breaker, and tripped all generators off. I suppose something similar could happen to an EDG.
I am a deck officer, early in my career aboard an ATB I was in the pilot house when the vessel lost power. After what seemed like an eternity the standby genset started and gave power.
On the same hitch it happened again. This time the standby genset failed to start. This was found to be dead 12v starting batteries. We were in open water and did not hit anything.
Later on I found out that these random power losses were due to faulty circuit breaker that was opening for no reason. It had been reported but the company was too cheap to buy a $ circuit breaker.
More recently I was on a wire boat when I lost the boat right next to an oil dock. This was later traced to the main fuel valve for the engine room. It was not a quick closing valve as has been mentioned. It was a regular ball valve. It had accidentally been left in the halfway position during a drydock.
Everything ran fine, but when I started working the main engines a bit to land the barge it starved the generator, causing it to shut down. When that happened I lose steering, nav lights, all electronics not on 12v battery backup and electronic engine controls. Miraculously we did not hit anything. After the incident I added a 24v battery backup to the controls, so I can at least maneuver the boat.
Both these incidents were caused by human error.
Diesel generators are one of the most reliable and industrially efficient generators, with a market size valued at $20.02 billion in and expected to grow to $29.51 billion by .
Yes, industrial generators can be one of the most expensive and valuable devices in your industry setting. But there come times when your generator might fail to function as efficiently as it does.
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So, what do you do?
It is important that you know the problem and can find a suitable solution for it. Understanding the relationships between major problems and solutions will help you guarantee that your generators function as effectively as possible, allowing you to get the most out of your investment. Knowing how to find and resolve common issues can allow you to work more efficiently while also understanding when you want the assistance of a proficient professional.
Here are some of the most common generator problems and their solutions.
Running out of fuel is one of the most frequent reasons a generator won’t start up. Checking for diesel should be your first step if the generator won’t start. In addition, if you’re using more diesel than normal, you may have a leak, which needs to be fixed right away.
Your gauges may be broken if your system suddenly runs out of fuel, even though the level readings indicate it is sufficient. It’s possible that the fuel gauge is locked in its position, telling you there’s adequate fuel while your generator is almost empty.
To filter out impurities such as dirt and debris, generators require a clean air filter. This air filter can’t support the effective operation of your generator if it becomes significantly dirty. Dirty filters may even shorten the lifespan of your generator.
The filter needs to be inspected not less than once every few months. If the filter is really unclean on each side, try to look for a substitute of the same size. To save replacement expenses and prevent frequent filter changes, consider installing a reusable filter.
When we are talking about diesel generators, wet stacking is a new type of fluid leak that results in inefficiencies. It happens when condensed water, oil, and unburned fuel collect in the engine’s exhaust and leak out as a thick, dark liquid.
By burning away the extra fuel, the wet stacking problem can be resolved. Additionally, by keeping an eye on exhaust temperatures and setting up steps for load bank testing and generator paralleling, you can stop wet stacking in the future.
Regardless of the model, one of the most prevalent problems with generators is battery issues. This is usually a result of a human error. It’s possible that the electrical board was actually turned off to allow for safe maintenance on the generator. Just looking at your circuit breaker and noting which slot was flicked off can solve this problem.
Unclean connections could be the cause of the problems. Dust and debris can cover the terminals that link the battery to the generator, making it difficult for the battery to make a solid connection. You will need to bring a wire brush for this issue. Use it to clean off any rust and dirt that have accumulated over time on these terminals.
Coolant distributes heat around the engine to prevent parts from freezing or overheating, maintaining your generator at optimal operating temperatures. The coolant in your generator works to counteract the high temperatures that result from the engine.
Low levels result over time from the coolant’s water evaporating due to prolonged exposure to those high temperatures.
Regular maintenance can guarantee that your engine has all the fluids it needs, particularly checks on the fluid level. Regular maintenance on the engine can typically avoid leaks of coolant, gasoline, or oil. To prevent low coolant, oil, and fuel levels, it’s important to understand the range of components and fluid levels to check while detecting generator problems.
Generators are electrical machines. These are prone to wear and tear at some point in time as there are multiple components involved in their functioning. Despite regular maintenance, certain problems might occur, causing the generator to break down. To avoid any hurdle in your regular industrial functions, you should know how to find a problem with the generator and what its solution will be.
One way to avoid any malfunctioning of the generator is to get your generator from trusted and reliable sellers like Central States Diesel Generators. With years of trust and known quality diesel generators, we ensure that every generator we sell is of top-notch quality and will not fail at any point in time.
The most prevalent issue with generators is improper maintenance. It’s often heard that choosing not to carry out routine upkeep in addition to inspecting the engine’s elements for wear and tear may result in troubles.
An automatic voltage regulator (AVR) is a component used in generators that automatically regulates voltage, which means it converts variable voltage levels into stable voltage levels.
When winding and connecting a circuit, find any obstructed circuit using a multimeter. If there was inadequate contact that led to the failure, cleanse the surface layer as long as it is smooth. At this stage, the connection must feel secure again. It’s possible that your generator’s wiring has been burned and turned useless if it operates but produces no electricity.
Turn on the generator and let it run continuously. During this period, keep an ear out for any odd noises, and if something feels off, turn off the generator. The engine must sound effortlessly and steady, with no clunking or flaring sounds.
Operating a generator in the pouring rain, snowy conditions, or on damp ground requires utmost care. Water could harm your generator’s outlets and electrical wiring, seep into the fan, alternators, and fuel, and lead to more damage.
A general capacitor is an essential component of a generator that modulates power flow, resulting in clean and dependable energy. To minimize voltage spikes, the alternator windings must be excited by a capacitor. It functions similarly to a battery, which accumulates electric charge when plugged into a power source.
The motor could show a number of issues, such as not starting, heating up, and vibrating, if the run capacitor breaks down. The motor cannot receive the full voltage required for proper operation if the run capacitor is malfunctioning.
If the generator is overworked, it may shut down to protect its internal parts. One way to fix this is to disconnect as many devices as possible from the generator and reset the circuit breakers. If the problem continues, there can be an internal component fault with the generator.
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