Garantising the performance of generator sets is not just a matter of periodic inspections: it is a technical discipline based on procedures, regulations, and operating criteria that ensure energy availability under any conditions.
Work on improving the performance of your generator sets in 2026
As we approach 2026, this article brings together validated procedures and practical industry experience to help technicians, maintenance managers, and infrastructure operators optimise their generator sets to guarantee continuity of supply in sectors such as data centres, critical industries, healthcare, telecommunications, and various emergency applications. Remember that carrying out proper generator maintenance is just as important as choosing the right generator set for your needs.
Summary of the 5 key steps
- Cleaning and basic maintenance → Prevents failures and ensures proper thermal behaviour to guarantee generator set performance.
- Software and control system updates → Precision, stability, and compatibility with new functionalities.
- Preventive replacement of critical components → Ensures sensitive elements do not compromise availability.
- Periodic performance testing → Technical validation of the equipment’s real operating behaviour.
- Structured preventive planning → Reduces breakdowns and optimises lifecycle.
1. Cleaning and basic maintenance
Why cleaning directly affects performance
Guaranteeing the performance and service life of generator sets is heavily influenced by their thermal behaviour and the integrity of their electrical systems. Dirt accumulation affects:
Thermal dissipation
- Dirt reduces airflow across radiators and fans.
- It increases engine and alternator temperature, affecting lubrication, insulation, and efficiency.
According to ISO 8528-13, continuous overheating can lead to insulation loss, reduced alternator stator life, and tripping of thermal protections.
Electrical connections and sensors
- Conductive dust, moisture, or grease can interfere with sensor signals or pressure probes.
- This generates false alarms, loss of measurement accuracy, and incorrect protection actions.
Corrosion
In coastal areas or industrial environments with chemical agents, corrosion accelerates degradation of terminals, canopies, bases, and metal components.
Dagartech technical recommendation:
Cleaning at least twice a year in standard environments and monthly in locations with dust, high humidity, or industrial contaminants.
Recommended technical cleaning procedure
- Safely shut down the generator set if required.
- Allow full cooling to avoid thermal shock.
- Clean the alternator with compressed air ≤ 2 bar to avoid damaging insulation varnish.
- Clean control panels without applying liquids directly (use lightly dampened cloths).
- Clean the radiator following the reverse direction of airflow.
- Final inspection for leaks after cleaning.
Recommended tools
- Compressed air with regulator.
- Antistatic brushes.
- Microfibre cloths.
- Approved contact-cleaner spray.
- PPE (mainly goggles and gloves).
2. Software and control system updates
The control system is essentially a specialised PLC that monitors electrical and mechanical parameters, triggers protections, and manages communication with external systems (ATS, BMS, SCADA, paralleling systems…).
Keeping it updated is essential for several technical reasons:
Key advantages of keeping firmware up to date
Error correction and stability
Control panel manufacturers release updates to resolve:
- Bugs detected in previous versions.
- Compatibility issues with new sensors or engine/alternator firmware.
Enhanced fault detection
Improved protection algorithms:
- New overcurrent detection methods.
- Refined alarms for low battery voltage or charging faults, among others.
Compatibility with advanced monitoring
New versions enable integration with:
- DSE 855 / DSE 890 (LTE/Ethernet).
- Modbus TCP/IP, J1939, SNMP.
- Dagartech software for telemetry and fleet management.
Safe update procedure
- Export the current configuration (full backup).
- Verify the manufacturer’s recommended version for that specific model.
- Carry out the update via USB or PC Interface Tool.
- Validate analogue and digital signals after the update.
- Test automatic start, manual start, and load sequences.
In critical installations, updates must be performed outside operational windows or with redundant equipment available (in accordance with NFPA 110 criteria for emergency systems).
3. Preventive replacement of worn components
Wear is inevitable due to vibration, temperature, start–stop cycles, and variable loads. Identifying critical parts and replacing them before failure is essential to ensure availability.
Critical components and their behaviour
Filters (oil, fuel, air)
- Saturated filters cause increased backpressure.
- Higher fuel consumption.
- Reduced available power.
Belts
- Alternator and fan belts may stretch, harden, or crack.
- A belt break results in almost immediate overheating.
Batteries
According to manufacturer recommendations:
- Minimum resting voltage ≥ 12.4 V (12 V batteries).
- Estimated service life: 2–4 years depending on ambient temperature.
- Sulphation is a common cause of failed starts.
Anti-vibration mounts
- They absorb vibrations and prevent structural damage. Knowing how to avoid vibrations in generator sets is essential to ensure generator lifespan.
- Over time they lose elasticity and cause abnormal vibration.
Generic replacement intervals (operating hours)
| Component | Indicative replacement interval |
| Oil filters | 500–600 h |
| Fuel filters | 500–600 h |
| Air filter | 500–800 h (depending on dust levels) |
| Engine oil | 500 h (according to engine manufacturer) |
| Belts | 12 months / quarterly inspection |
| Batteries | 2–4 years |
| Cooling hoses | 2–3 years |
These intervals follow generic recommendations based on maintenance standards from industrial diesel engine manufacturers. Always refer to the specific engine manufacturer’s guidelines.
4. Periodic performance testing
Load tests make it possible to validate:
- Voltage and frequency stability.
- Transient response (step load).
- Capability to deliver continuous power (PRP) or standby power (ESP).
- Thermal behaviour under real load.
Importance according to standards
- ISO 8528-6 defines performance criteria under load variations.
- In critical facilities, NFPA 110 requires periodic testing and automatic starts.
Recommended types of tests
No-load test (monthly)
Validates starting, oil pressure, temperature, and overall condition.
Partial load test (quarterly)
Loading between 30% and 50%:
- Helps prevent exhaust condensation.
- Reduces the risk of wet stacking in diesel engines operating at low load for prolonged periods.
In addition to verifying generator performance under load, it is crucial to ensure that electrical and control protections operate correctly. The importance of protections in generator sets—such as overcurrent, overload, undervoltage, overtemperature, or earth-fault protections—lies in the fact that they allow a generator set to react to abnormal conditions before they become critical failures. A misconfigured or non-operational protection can invalidate any benefit of a load testing programme.
Resistive load bank (annual)
This allows:
- Bringing the engine to its optimal thermal curve.
- Verifying performance at full load.
- Ensuring the alternator delivers its rated power.
5. Preventive maintenance planning as a key tool to improve generator performance
A solid preventive maintenance plan should include:
Visual inspections
Checking for leaks, wear, abnormal vibrations, corrosion.
Functional checks
- ATS (automatic and manual).
- Remote control signals.
- Emergency mode.
- Alarms and shutdowns.
Full annual maintenance
- Seal inspection.
- Block heater check.
- Electrical panel cleaning.
- Certified load test.
- Firmware update.
- Complete documentation record (recommended by ISO 9001).
Maintenance with Dagartech support
Dagartech certifies:
- Performance under ISO 8528 standards.
- Maintenance protocols based on real field experience.
- Integration with advanced monitoring systems.
- Approved spare parts.
From Dagartech, we help you ensure the performance of your generator sets and support you with the maintenance of your equipment:
- Technical assistance
- Download our spare parts catalogue
