Selection guide
How to choose a generator
Choosing the right generator is not only about price or output. Every operation has different demands — on load, running time, the equipment being powered and standby supply.
- Power and sizing
- Duty type
- Automation and ATS
- Service and warranty
Why the right selection matters
What decides when you choose a generator
A correctly sized diesel generator delivers reliable operation, safety and lower long-term costs. A wrong choice shows itself at the first load test or the first grid outage.
Selection depends not only on the machine's technical parameters, but also on how it will be used, where it will be installed, what technology it will power and how service will be covered. Below we summarise what to focus on.
Purpose of use
Standby, regular or continuous operation?
Required output
kVA with reserve for starting currents
Type of load
Machines, pumps, lighting, cooling
Installation site
Indoor / outdoor, noise, space
Automation
ATS, monitoring, protective functions
Service backup
Availability of service and spare parts
Detailed guide
Clarify what the generator will be used for
The first step is to define the purpose of the generator. A solution for backing up a building is different from one for an industrial process or a temporary construction site installation.
If the generator only acts as a reserve during grid outages, the choice differs from a unit that has to power an operation regularly or continuously.
Calculate the required output
The basic parameter is the required output in kVA. Simply adding up the rated power of all connected equipment is not enough — several factors have to be considered together.
An undersized generator can struggle when equipment starts up or run unstably. An oversized solution is unnecessarily expensive to buy and to run. Output in kW equals the kVA value multiplied by the actual power factor of the connected load — 0.8 is an illustrative value only (100 kVA at a power factor of 0.8 gives 80 kW). Always verify the connected load and the generator specification, and treat motor starts and transients separately. There are no automatic oversizing percentages: the required rating is confirmed from the manufacturer's datasheet for your load profile, starting loads, duty and project conditions.
Consider the type of connected technology
What exactly the generator will power matters greatly. Equipment with electric motors or high starting peaks requires a more careful design of both output and configuration.
Standby, prime or continuous duty?
It is essential to distinguish whether the generator will run only as a backup during outages, as a regular source of energy, or as the main supply where no stable grid exists. These duties correspond to the manufacturer's rating definitions: ESP (standby), PRP (prime) and COP (continuous).
The rating categories ESP, PRP and COP are consistently defined; the rated outputs and the permitted load and duty limits, however, must be checked for the specific model. A prime rating does not automatically mean the unit can run at continuous COP load — always confirm the applicable rating from the manufacturer's datasheet for your duty.
Installation site and operating conditions
The generator also has to be chosen according to where it will be installed. Sometimes compactness is key, other times an acoustically attenuated version or a robust solution for demanding outdoor operation.
Automation and safety
For standby applications, an automatic reaction to a grid outage is usually important. The correct configuration of the control system has a fundamental effect on the reliability of the whole solution.
An ATS transfers the supply after the engine has started and voltage and frequency have stabilised — the changeover itself involves a brief interruption. Sensitive loads that cannot tolerate it are bridged by a UPS until the generator takes over.
Service and long-term reliability
When choosing a generator, it is not only the machine that matters, but also the availability of service, spare parts and technical support. A quality solution is designed with the entire operating life in mind.
Selection process
How the selection of a suitable solution proceeds
The best path is to assess the specific operation and its real requirements. The selection is usually resolved in these steps — on their basis we can recommend a suitable generator and the optimal configuration.
- 01
Type of application
What the generator will power and in which environment.
- 02
Required output
Load profile, starting loads and reserve for growth.
- 03
Character of the load
Motors, electronics, sensitive technology.
- 04
Installation site
Indoor or outdoor, noise, ventilation, access.
- 05
Duty regime
Standby (ESP), prime (PRP) or continuous (COP).
- 06
Level of automation
ATS, monitoring, protective and signalling functions.
Related pages
Czech projects — scope as agreed
For Czech projects the delivery may include, as agreed: generator supply, design of the installation, commissioning on a prepared site, turnkey realization and a service contract. The scope is always clarified together during consultation and confirmed in the quotation.
International supply — EXW CZ/NL
International direct sales are preferably EXW Czech Republic / Netherlands; transport is agreed individually. Installation and service abroad are possible in agreed cases and are always confirmed individually by location and model. Manufacturer warranty.
We will help you choose the right generator
We will propose a suitable solution according to your operation, the required output and the intended use — standby or continuous supply.