Risks and Consequences of Using Generator Sets at a Low Load Operation

Minimum load for generators

Generator sets are designed to operate close to their rated power, and maintaining them properly is essential to ensure optimal performance. Every generator has a recommended minimum load, typically around 50% of its rated capacity. Operating below the generator minimum load for extended periods can lead to serious issues and reduced lifespan.

Main symptoms of something malfunctioning

One should be concerned when:

  1. The engine gives off oil mixed with fuel through the exhaust manifold – including the exhaust outlet or the muffler.
  2. There is oil spillage, dripping of oil of a very dark colour, as if burnt.
  3. The exhaust gives off a white smoke, more smoke than usual is seen or there is soot coming out of the exhaust outlet.
  4. The valves and tubing are clogged by dirt (presence of cinder).

The effect of low load on generator performance

“We saw engines working continuously for 24 hours at a tenth of their load and exhaust manifolds with six centimetre holes reduced to one centimetre by the accumulated cinder and oil”, Genesal Energy Technical Director Guillermo Docampo explains.

The effect of low load on a generator includes serious internal damage over time, particularly due to incomplete fuel combustion and oil dilution. These issues directly impact engine health and efficiency.

Negative effects of low load:

  1. Large accumulation of soot (cinder) in the pistons, in the grooves of the piston rings, in the valves and the turbocharger. If, subsequently, the engine functions at full load the pistons may be blocked by faulty lubrication.
  2. Low temperatures will result in insufficient combustion of the fuel, which, in turn, will cause the lubricating oil to be diluted and lose its properties because part of the fuel has mixed with the oil.
  3. Grinding of the cylinder liner. Excessive wear.
  4. The non-consumed fuel and the lubricating oil will also penetrate the exhaust manifold and will possibly exit through its seals, being very obvious -almost scandalous- because of its burnt aspect and by the stains it causes ((see photo below)).

Non-consumed fuel exiting through its seals

Important: Do not run an engine generator set without a load for more than 15–20 minutes unless strictly necessary. Prolonged operation without load can lead to internal damage, high oil consumption, and a shortened lifespan of the equipment.

Why does low-load functioning in a repeated and continuous way cause an increase in oil consumption?

In reality, when an engine works at a low load, the ideal working temperature of the engine is not attained. This favours oil flow towards the upper part of the piston, because a correct adjustment within the piston-rings-cylinder assembly was not achieved. This is due to the lack of dilation resulting in an increased consumption of oil; the oil flows more easily between the valve guides and the stems due to a greater clearance because there was no sufficient warming.

How to prevent malfunctions? Is it possible to reduce the risks?

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Generator load profile and step load explained

Technical article: load profile and consumption of a generator

Knowing the type of loads a generator must power is essential to calculate its required power correctly.

The load profile and the step load —the initial load applied at start-up— are key factors in generator sizing. Power demand is not static; it fluctuates depending on the equipment and conditions, and ignoring these variations can lead to overloads, inefficiencies, or equipment failure.

The power that a generator set manages isn’t an absolute and static value. Its level tends to fluctuate according to certain factors and processes, and it does so differently in each type of unit.

For this reason, calculating the power a generator set needs to function is not a simple operation. Different variables must be taken into account which, if not considered, can cause serious issues in our installation.

For instance, an overload in any of the phases can cause overheating and voltage imbalances. This can cause damage both in the generator set and the equipment connected to it.

Start-up: the first step load

The generator set is going to be limited during its start-up by what is called the first step load, that is: the total transient load that the genset is initially capable of enduring until reaching its stable regime with some transient variations in voltage and frequency.

This is why it’s important to verify the characteristics in the nameplates of the equipment connected to the generator set, and to be aware of the possible transient effects which they may suffer during its start-up processes

Certain equipment such as pumps or motors with variable drives, for instance, may increase their current temporarily during commissioning. 

Likewise, elements such as UPS’s (uninterruptable power supplies) can cause harmonic distortions which must be contemplated in our calculations.

Which parameters affect the dimensioning of loads? 

  1. The first parameter to contemplate is the type of load. As we’ve pointed out, some units experience transient increases in current during start-up. With this in mind, we’ll pay special attention to the following loads:
  • Uninterruptable power supplies (UPS). The alternator’s rated power is oversized depending on the installation.  
  • Big motor loads. They can increase starting power to up to 6 times the power, depending on the type of start-up.  
  • Lighting loads (with special attention to sodium vapour lighting and metal halides). 
  • Systems with Variable Frequency Drives (VFD). These can cause an oversizing from 40 to 100%. 
  • Other loads which are especially sensitive to transients and voltage and frequency variations. 
  1. Another factor we must keep in mind is the type of start-up of the motor in question. This is due to the fact that each type of starter requires a specific starting current, which must be higher than the unit’s rated current. Thus, we find that:
  • Electric motors with star-delta starting: its “starting current” will be equal to three times the rated or operating current. 
  • Direct starting motors: demand 6 times nominal current. 
  • Starter motors with variable frequency drives: special attention must be payed to its technical sheet as normally the ramp and increase in speed is configurable. 

Other important aspects to consider for genset load calculation

To finish carrying out this entire calculation of power with maximum precision, other variables must be kept in mind such as: 

  • Power factor during start-up.
  • Starter power.
  • Rated power factor.
  • Rated power
  • Efficiency
  • Number of start-ups

Ultimately, we must be extremely rigorous in this calculation. To avoid any surprises, it’s vital to know the type of load we’re dealing with as well as its behaviour. All, with the objective of the generator set always powering a balanced load, without generating unexpected peaks.

 

Discover our handy guide to choosing the right power generator

10 Benefits of having a power generator set

Technical article. 10 benefits and advantages of electric generators

In a world increasingly dependent upon energy, technology and data, it is a priority to have a reliable and sustainable supply of electricity. This is precisely what generator sets offer us.

The importance of electric generators

The importance of generators lies in their ability to provide continuous power during outages and support critical infrastructure. In times of natural disasters or unexpected power failures, generators ensure that hospitals, data centers, and emergency services remain operational, safeguarding lives and essential data. Moreover, they enable businesses to maintain productivity and prevent financial losses, highlighting their crucial role in modern society.

However, the virtues of these devices go beyond what meets the eye and it is worth knowing them. We compiled a list of 10 fundamental benefits so that none of them is left out:

What are the main advantatges of having a generator set?

1. Uninterrupted Power: The Importance of Ensuring Continuity

Electricity supply no matter what. Generator sets are meant for you to always have electricity whatever happens. This means that problems with the electrical network will no longer be critical for you, given that you will be constantly backed up by an autonomous generation solution which is 100% effective.

2. Say Goodbye to Downtime: Boosting Productivity

Farewell to losses: relying on the backup of a generator set in your business allows you to forget about time and productivity losses supposed by power blackouts.

3. Empowering Autonomy: Expanding Possibilities

More autonomy, more possibilities: when using an energy distribution solution such as a genset you are no longer dependent on the limitations imposed by the infrastructure of the electrical network. This means more peace of mind and, most of all, more freedom when it comes to conceiving your business projects and letting them fly.

4. Mobile Power Solutions: Enhancing Flexibility

It allows you more mobility: generator sets allow you to have a power supply in areas lacking an electrical network. Therefore, they eliminate obstacles when it comes to carrying out projects and they contribute to the development of remote or disadvantaged areas.

5. Tailored to Your Needs: Customized Designs

Your project is in charge: at present, the design of gensets is tailored to the clients’ needs and the features of their projects. According to your requirements, you will be able to choose: between engines using different fuels, between stationary or mobile generators, between hybrid and marine generators, as well as between different profiles of power delivery and of use.

6. Adding an Extra Layer of Protection: Ensuring Security

An additional security layer: the consequences of a power outage go beyond the mere issue of productivity. A sudden “blackout” can cause severe damage to our devices and machinery and this is something that can be avoided if we have the backup provided by an emergency genset.

7. Sustainable Energy: Reducing Environmental Impact

It contributes to sustainability: as opposed to the great impact left by the emissions produced by thermal power stations, generator sets offer a model of energy production which increasingly allows one to leave the least possible environmental footprint. The present-day trend is represented by generators using fuels with low CO2 emissions, like natural gas or liquefied petroleum gas (LPG). Moreover, these are low noise devices, producing no sound pollution.

8. Long-Term Value: Making a Sound Investment

It is an investment which pays off: A generator set will give you an extremely valuable service and will continue to do so for a long time. Most certainly, with appropriate use and maintenance, you will have a safe, long-term investment.

9. Streamlined Energy Production: Enhancing Efficiency

More efficient energy production: statistics show that electricity losses in the Spanish network of transport and distribution amount to 8% of all available production. Using distribution solutions such as gensets, one manages to reduce such losses. Moreover, we contribute to avoiding overloads in the network during the peak hours.

10. Cutting Costs: Maximizing Savings

You save in consumption: gensets allow you to reduce costs, by helping you manage the electricity demand in a more economical way. For example, you can use them as a backup during peak hours, in order to avoid excessive consumption. According to calculations, you can save up to 40% in this time slot.

 

In short, a generator set brings you peace of mind, opens up a large spectrum of business opportunities and all this in an effective and sustainable way.

Do you think it could be an interesting solution for you as well?

At Genesal Energy we have a wide experience in the design of personalized generator sets and we’re here to help you turn your project into reality.

 

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Energía de Hoy interviews Alexander Blanco López, head of the Operations Management department

Operations Management is one of our most strategic departments. The magazine Energía de Hoy expressed interest in finding out how it works, its development and its operation. We’re sharing with you the interview that the magazine had with its Head of Department, Alexander Blanco López, in order to get a closer understanding of this area.

Alexander Blanco López is the Head of Operations Management at Genesal Energy. He studied Industrial Design in Ferrol and upon obtaining his post-graduate qualifications in the University of A Coruña he began working in Genesal Energy in January of 2007. Throughout these past 12 years, Blanco has grown professionally in the company. He is currently the Head of Operations Management, coordinating the interrelationship between the company’s different departments.

As you’ve made it known to the public, 2018 has been a very positive year for the company both in the international as well as the domestic market. What is Genesal Energy’s success based on?
From my point of view, our success is based on, above all, our versatility. In Genesal Energy we advise our customers, we assist them from the beginning because not only do we manufacture gensets, we also carry out “turnkey” projects which means we’re on top of everything during the whole process. We design and manufacture custom-made units, we take care of the installation, commissioning and subsequential maintenance works. I think that’s the key. While other big companies only manufacture, for us, the process starts when the client has an energy requirement and lets us know about it, and from that moment onwards we assist them, advising them and accompanying them at all times. Our link with the client doesn’t end in the factory. In reality, at Genesal Energy we’re really devoted to a comprehensive and highly personalised service. We don’t believe in the concept of mass production. Every sale the sales department closes we take on as a personalised project and a relationship of trust.

What perspective do you have for 2019?
We want to continue growing. 2018 was a very good year, the company took a great leap forward. For this reason our goals are centered around at least maintaining the levels achieved in the last fiscal year, where turnover grew 40% from 2017. The objective is to maintain these numbers, to consolidate them and to continue in the path of continuous and sustained growth.

This year you’ll be launching the new canopies by ranges. What will be their main features?
We’re finalizing the development of the first model of the new canopies so that the client, when they receive our gensets, perceive great quality. We’ve wanted to take it a step further and improve key aspects like utility and maintenance without them having an impact on the cost. The new canopies will adapt better to our our new production systems. In Genesal Energy we install different brands, both in the realm of engines and alternators and now, with this new generation of canopies, the sound attenuation of the gensets will improve and maintenance works will be simplified. This improvement has been promoted by the experience we’re acquiring not only in our own market, but also in other external markets where the requirement levels are higher, by taking note of this and trying to achieve excellence.

The development of products for the international market is without a doubt one of your strengths. Where does Genesal Energy operate exactly? Do you expect to expand this market short or medium term?
At Genesal Energy we carry out projects across the five continents and we have a magnificent relationship with big companies who develop projects worldwide and who we support. In this sense, the commercial department treats all our clients as if they were the only one, as they really are the ones who help to not only maintain us where we are, but also to improve and continue growing. It’s because of this that all throughout the month of January, a team of the Genesal Energy sales department travelled around the world to continue strengthening the relationships with clients and suppliers.

Offering a comprehensive service to your clients also contributes to the success of this company. What does this service entail?
We offer complete support to the client: telephone assistance, in situ, we visit their site, we take care of the set-up of the genset in any type of installation. We respond to any of their technical queries. On the other hand, once they’ve made a purchase order, we carry out a custom-made design, we manufacture the product, we carry out tests in our headquarters in Bergondo (100% of the manufactured units are tested before leaving the factory, at 110% of the load), we send over the genset, install it, and then we carry out another test in situ. We also offer our after-sales maintenance service throughout the whole lifespan of the genset.
At Genesal Energy, we don’t leave any part of the process on the sidelines. We’re aware of every detail, from the most basic elements to the genset’s maintenance works, both in the preventive and corrective sense. And if any fault should occur, we’re always there, implementing remote maintenance systems through which we know the status of the genset in real time and are made aware of any problems that could arise, carrying out the necessary preventive actions before a mains failure could occur and the genset is no longer working. We look for excellence for our customers, we know they make large investments in machinery that costs a lot of money, so we must guarantee their correct operation.

Source: Interempresas Media – Energía de hoy Magazine

Steps to choose the right generating set