Buy new and second-hand generators – Atlas Copco QAS, SDMO, Doosan, JCB, Himoinsa, Pramac, direct from specialist dealers. Whether it’s a construction site without mains connection, an event, emergency power for business or agriculture, or peak load in industry: a diesel generator (generator, emergency power unit, genset) supplies electricity where there is none. We stock generators ranging from 20 to 250 kVA from Kraus Baumaschinen in Frankenthal and Bontebok in the Netherlands – with power output, year of manufacture and operating hours listed in the advert, many at fixed prices.
Which generator suits your needs?
20 to 40 kVA – construction sites and trades: Atlas Copco QAS 20/30/40, SDMO R22/R33/R44, JCB G18/G40, Doosan G30/G40, Worms/IMER Silentstar 20. Powers site huts, cranes, mixers, tools and lighting; sound-insulated, mounted on a chassis or skid.
50 to 100 kVA – larger construction sites, events, emergency power for small and medium-sized businesses: Atlas Copco QAS 60/80/100, Doosan G80/G100, SDMO R66/R90, Aggreko 60, Ashita 50. Cranes, pumps, air conditioning, stage equipment, cold stores.
120 to 250 kVA – industry, data centres, large construction sites: Atlas Copco QAS 150, Doosan G150, SDMO R135, JCB G165, Himoinsa HFW-250, Pramac GSW 115, Gesan 150, Bruno 150. Emergency power for businesses, agriculture (including milking and ventilation systems), tunnel and infrastructure construction sites.
Battery instead of diesel: Atlas Copco ZBP 2000 as an energy storage system – combined with a small diesel generator, it covers peak loads and eliminates the need for the engine to run at night.
Power is specified in kVA (apparent power); the usable active power in kW is around 20 per cent lower than this at a typical power factor of 0.8. A 100 kVA generator therefore delivers around 80 kW.
What to look out for when buying a second-hand generator
Operating hours and usage profile: Emergency generators often have only a few hundred hours on the clock – in such cases, age is a key factor (seals, hoses, battery, fuel). Construction site and hire generators run for 2,000 hours a year; industrial engines (Perkins, Deutz, Volvo, Kubota, Yanmar) can last 20,000 hours or more with proper maintenance.
Test run under load: Voltage and frequency (400 V / 50 Hz) must remain stable under load; the automatic voltage regulator (AVR) must not fluctuate. If no load bank is available, connect at least one load and monitor the display.
Engine: Cold start, smoke emissions, oil and coolant levels, leaks, condition of the radiator and air filter. Emissions standard: New machines comply with Stage V; older units (Stage IIIA or without) are cheaper but can no longer be used on construction sites with emissions regulations.
Generator and control cabinet: Insulation values, sockets and fuses, residual current protection, control system (manual start, automatic start for emergency power, automatic transfer switch (ATS)). For emergency power applications, the control system must be compatible with the emergency power supply concept.
Housing, fuel tank, chassis: Soundproof enclosure (is the insulation intact?), rust-free fuel tank, trailer chassis with brakes and lighting, operating licence for road transport. CE marking and a declaration of conformity are required.
| Power | approx. kW | Typical application | Typical models |
|---|---|---|---|
| 20–40 kVA | 16–32 kW | Construction sites, trades, containers, lighting | Atlas Copco QAS 20–40, SDMO R22–R44, JCB G18–G40 |
| 50–100 kVA | 40–80 kW | Cranes, pumps, events, emergency power for SMEs | Atlas Copco QAS 60–100, Doosan G80/G100 |
| 120–250 kVA | 96–200 kW | Industry, agriculture, large construction sites | Atlas Copco QAS 150, Doosan G150, Himoinsa HFW-250 |
Brands and dealers
Atlas Copco (QAS), SDMO/Kohler, Doosan, JCB, Himoinsa and Pramac are the standard European brands with local parts supply; Genelec, Gesan, Bruno, CO.G.E.N. and Ashita are solid alternatives in the price segment below; Buchholz supplies PTO generators for tractor operation. Our dealers: Kraus Baumaschinen in Frankenthal (new JCB and Atlas Copco units, certified second-hand generators) and Bontebok Trading in Friesland (extensive range of second-hand units from 20–150 kVA at fixed prices, export). Filter by manufacturer, engine power, year of manufacture, operating hours and price.
Frequently asked questions about used generators
How much kVA do I need?
Add up the power of all loads running simultaneously, and for motors (pumps, compressors, cranes), factor in the starting current – three to six times the rated power for a few seconds. Then allow a 20–25 per cent reserve. A diesel generator operating at less than 30 per cent capacity for prolonged periods will become fouled with soot – but one that’s too large is also unsuitable.
How much does a second-hand generator cost?
Second-hand 20–40 kVA generators start in the mid four-figure range, whilst 100–150 kVA units are usually in the five-figure range. Factors affecting the price include power output, year of manufacture, operating hours, emission standard, sound insulation and control system (automatic start). Many of our listings have fixed prices.
How many operating hours are still acceptable?
Industrial engines in generators typically run for between 15,000 and 30,000 hours. A generator with fewer than 5,000 hours is considered to be in good condition; more important factors are maintenance records, a test run under load and the condition of the generator and regulator.
How loud is a generator?
Sound-insulated generators (‘Silent’, QAS, Silentstar) produce 65–75 dB(A) at a distance of 7 metres – a requirement on building sites in residential areas and at events. Open generators are significantly louder and are only suitable for use in remote locations.
Can I use the generator as an emergency power supply for my business?
Yes, provided it has an automatic start (AMF) and an automatic transfer switch (ATS), which switches over in the event of a mains power failure. An electrician must install the switch in accordance with VDE standards; generators without automatic start can usually be retrofitted. Ask about the control system in the advert.
Which emissions standard do I need?
There are no specific requirements for emergency power or on company premises. Stage V is required on construction sites for public sector clients and in low-emission zones. A newer generator is therefore worth considering for hire and construction sites, whilst an older, cheaper machine is often sufficient for emergency power.
Can I lease a generator or finance it via a hire-purchase scheme?
For many listings, you can submit a no-obligation leasing or hire-purchase enquiry directly. You’ll need to clarify the terms with the dealer or their finance partner; the purchase and payment are handled directly between you and the seller.
An overview of all types: Construction machinery · Related products: Lighting masts, construction compressors