The Könner & Söhnen KS 4000iE S is a petrol inverter generator with a stable 230V pure sine wave output for compatible sensitive electronics. It provides 3.5kW rated power and 4.0kW maximum power, with electric and recoil starting, a sound-insulated enclosure and integrated wheels for easier movement.
Free delivery to mainland Great Britain only.
At a glance
| Rated / maximum power | 3.5kW / 4.0kW |
|---|---|
| Output | 230V, 50Hz pure sine wave |
| Sockets | 2 × UK 13A household sockets — both 230V |
| Starting | Electric and recoil |
| Runtime at 50% load | 7.8 hours* |
| Fuel tank | 12 litres |
| Net weight | 40kg |
*Fuel consumption and runtime vary with load, fuel quality, season, altitude and generator condition.
Why choose the KS 4000iE S?
- Pure sine wave output: stable 230V, 50Hz power for compatible sensitive electronics.
- Electric and recoil starting: flexible starting options with a 1.6Ah starter battery.
- Economy mode: reduces engine speed at lighter loads to lower fuel consumption.
- Multifunction display: shows load, fuel level, voltage, frequency and operating hours, with status indicators.
- Parallel-ready: compatible with the separately available KS PU1 parallel unit.
- ATS-ready: an 8-pin connection supports the separately available KS ATS 4/25 Gasoline automatic transfer switch.
- Integrated transport system: wheels and a lifting handle make the 40kg generator easier to reposition.
Power, fuel and connections
Plan for rated power
Use the 3.5kW rated output for normal load planning. The 4.0kW maximum rating is for short starting peaks rather than continuous operation.
Petrol operation
Use unleaded petrol rated 90–95 octane with no more than 10% ethanol. The generator is supplied without fuel or engine oil.
Optional connections
The generator supports compatible parallel operation and the KS ATS 4/25 Gasoline unit. Both accessories are purchased separately.
Technical specifications
| Voltage / frequency | 230V / 50Hz |
|---|---|
| Rated power | 3.5kW |
| Maximum power | 4.0kW |
| Maximum current | 17.4A |
| Power factor | 1 |
| AC sockets | 2 × UK 13A household sockets — both 230V |
| DC output | 12V / 8.3A |
| Parallel connection | Yes — compatible KS PU1 unit required |
| ATS connection | Yes — compatible KS ATS 4/25 Gasoline unit required |
| Protection class | IP23M |
| Engine | KS 240i, 223cm³, single-cylinder four-stroke petrol, air-cooled |
|---|---|
| Engine power | 7.5hp |
| Starting | Electric and recoil |
| Fuel tank | 12 litres |
| Runtime at 50% load | 7.8 hours* |
| Crankcase capacity | 0.6 litres |
| Starter battery | 1.6Ah |
| Alternator winding | Copper |
| Net dimensions (L × W × H) | 620 × 440 × 510mm |
|---|---|
| Packed dimensions (L × W × H) | 630 × 475 × 570mm |
| Net / gross weight | 40kg / 43.4kg |
| Noise level | 66dB(A) at 7m / 91dB(A) sound power |
*Fuel consumption and runtime vary with load, fuel quality, season, altitude and generator condition.
What's included
- KS 4000iE S inverter generator
- Spark plug wrench
- PH2 screwdriver
- Accessory case
- Operating instructions
Before first use
- The generator is supplied without engine oil or petrol. Do not start it until the correct oil has been added.
- Use four-stroke petrol engine oil; the manufacturer recommends SAE 10W-30 or 10W-40.
- Use unleaded petrol rated 90–95 octane with no more than 10% ethanol.
- Operate outdoors in a well-ventilated area on a firm, level surface, away from doors, windows and combustible materials.
- Read the owner's manual before starting, and connect appliances only after the engine is running steadily.
Manuals and downloads
Warranty
Manufacturer's warranty: 1 year or 1,000 operating hours, whichever comes first, from the date of purchase.
The warranty covers manufacturing defects, subject to the manufacturer's warranty conditions. Eligible faults may be repaired or the product replaced. Retain your proof of purchase and any completed warranty documentation supplied with the generator.
For help with a warranty claim, contact Energian with your order number, generator serial number and a description of the fault.
Frequently asked questions
Is the KS 4000iE S suitable for sensitive electronics?
Yes. Its inverter system produces a stable 230V, 50Hz pure sine wave output. Always keep the connected load within the generator's ratings.
Can it start automatically during a power cut?
Yes, when installed with the separately available KS ATS 4/25 Gasoline automatic transfer switch. Any connection to fixed wiring must be completed by a qualified electrician.
What sockets does it have?
It has two 230V UK 13A household sockets, plus a 12V / 8.3A DC output.
Does it include oil or petrol?
No. Add the correct four-stroke engine oil before first use and fuel it with suitable unleaded petrol.
Energian support
For help choosing a generator contact Energian on 020 8064 0335 or info@energian.co.uk. For after-sales support, have your order number and generator serial number ready.