How to choose your site generator?
Construction site generators are essential for providing electricity on building sites. To guarantee reliable power for a construction or renovation project, choosing the right model is crucial. Whether you need electricity for tools, equipment or lighting systems, there are several factors to consider when making the best choice.
Download our summary table on how to choose your generator according to the type of equipment.
What is the purpose of a generator set?
A generator is an autonomous source of electricity. It provides a reliable source of energy when there is no access to the electrical grid. On a construction site, it powers equipment such as power tools and lighting systems. Away from construction sites, it can also be used as a back-up generator for a home or for outdoor leisure activities. Operation is simple: a gasoline or diesel engine drives a generator that converts mechanical energy into alternating current.
Generator power for a generator set
The power of a generator varies considerably, from 2 to 200 kVA depending on the model. Generally, power is expressed in kW (kilowatts) or kVA (kilovoltamperes). In simple terms, 1 kVA is equivalent to approximately 1 kW.
It's crucial to determine the power required for your specific needs. For occasional use, 1,000 to 3,000 W may be sufficient for a few tools or lights. However, for professional use or more demanding worksites, choose a generator of at least 10,000 W.
If you want to use the generator as an emergency power supply at home, a 5,000 to 6,000 W model will be more appropriate. To protect sensitive electronic equipment, opt for a model with "Inverter" regulation, which guarantees a stable, high-quality power supply.
The different types of generator sets
All generator sets operate on a similar principle, but their technologies vary. There are three main categories, and two types of engine.
Gasoline-powered generators
Gasoline-powered generators are often chosen for their light weight and ease of transport. They are particularly suited to small worksites or temporary jobs requiring greater mobility. Their engines are generally small, quick to start and easy to operate. What's more, these models are often more affordable, making them economical for intermittent needs or short-term projects. However, their autonomy is more limited compared with diesel generators, and they require more frequent refuelling.
Diesel generator sets
Diesel generators are distinguished by their robustness and efficiency. They are designed for intensive applications, ideal for large worksites requiring continuous power. Their longer-lasting engines consume less fuel than gasoline-powered models. Large-capacity tanks extend periods of uninterrupted use. This makes them ideal for long-term projects or harsh environments. Depending on the model, you can choose between single-phase, three-phase or mixed power supplies.
Soundproof generators
Soundproof generators include an insulated cabinet to reduce noise pollution. They limit noise levels to less than 90 dB, while other models can reach 105 dB or more. As well as being quieter, these units are compact, lightweight and quick to install, making them ideal for occasional use where discretion is essential. However, this noise reduction reduces their power output, which rarely exceeds 2 kW. They are mainly powered by gasoline engines, often in 2-stroke or 4-stroke versions, and are suitable for applications requiring moderate power.
Which engine to choose for a generator?
Generator sets use 2-stroke or 4-stroke engines. 2-stroke engines are lightweight and compact, ideal for temporary applications and modest needs. However, they consume more fuel and have a shorter service life. By contrast, 4-stroke engines, available in gasoline and diesel versions, offer better fuel economy and emit less pollution. 4-stroke petrol engines are suitable for moderate use and are quieter. As for 4-stroke diesel engines, although bulky, they are suitable for intensive applications, offering durability and reduced fuel consumption.
What type of starter should I choose for my generator set?
Pour les groupes électrogènes à essence de faible puissance (< 3 kW), vous avez le choix entre un lanceur ou un démarreur. Si vous prévoyez une utilisation occasionnelle, un lanceur suffira. Pour une utilisation quotidienne, il est préférable de choisir un modèle équipé d’un démarreur, car il simplifie l’usage tout en nécessitant un entretien minimal de la batterie. Les autres groupes électrogènes incluent généralement un démarreur avec un mode manuel de secours pour garantir une fiabilité en toutes circonstances.
How efficient is a generator?
To maximize the life and efficiency of your generator, operate it at around 80% of its maximum output. This helps reduce engine wear and avoid overloading, while ensuring stable, reliable performance.
First determine the power required by adding up the total power of the devices you plan to connect. Then multiply this total by a safety factor of 1.20. For example, to power equipment requiring 4,000 watts, choose a generator capable of delivering at least 4,800 watts (4,000 x 1.20). Choosing a model with a slightly higher capacity ensures more efficient and prolonged use, while protecting your equipment from the risk of overload.
What is the autonomy of a generator?
The autonomy of a generator depends on the capacity of its fuel tank and the power of the load. In general, models with larger tanks offer longer autonomy. For portable models, autonomy varies from a few hours to a full day, depending on tank size and intensity of use.
A model like the Pramac 1.9 kW petrol generator has a 4.5-liter tank and consumes 1 l/h, giving you around 4h30 of autonomy.
You can also opt for the S12000 11.9 kVA petrol generator with its 4 hours 30 minutes autonomy.
Looking for greater autonomy? ThePX5000 3.8 kW petrol generator has a 27-liter fuel tank and consumes 1.92 l/h, giving you 14 hours of autonomy.
Discover our full range of portable generators here.
What types of regulation on a group?
Generator sets can be fitted with a variety of regulation systems to ensure a stable power supply. The AVR (Automatic Voltage Regulator) is commonly used, automatically adjusting the output voltage to maintain constant performance. For more sensitive requirements, such as powering electronic devices, the Inverter regulator is recommended. This system converts direct current into stable alternating current, delivering high-quality electricity with constant frequency and voltage. Inverter-controlled gensets are particularly suited to applications requiring a precise, stable power supply to protect delicate equipment.
Five points to consider when choosing a portable generator
Here's a guide to help you select the generator best suited to your needs.
- Determine your energy needs
Before buying a generator, assess your energy needs. Calculate the power required for the equipment you'll be using on site. Make sure you choose a model capable of supplying enough power for all your equipment.
- Choose the right wattage
The power of a generator is measured in kilowatts (kW). Make sure you choose a model with adequate power for your needs. It's best to choose a slightly oversized model to avoid problems of under-powering.
- Consider quality and reliability
Portability is important, especially if you need to move the generator from one site to another. Generators vary in size and weight; compact models are easier to transport but may have a lower capacity. Make sure the model you choose is suitable for your site conditions and sufficiently robust.
- Take noise levels into account
Generators can be noisy, which can be a nuisance on a construction site. Opt for a model with a reduced noise level for the comfort of workers.
- Check fuel consumption
Fuel consumption has an impact on operating costs. Choose a fuel-efficient model to cut costs and limit pollutant emissions.
By following this advice, you'll be able to choose the ideal site generator for your needs, ensuring that your work is carried out safely and efficiently. Don't forget to take into account the specifics of your site, and consult us if necessary to make the best choice.
