Inverter generator KS 4000iE S

Max power4.0 kW
Nominal power3.5 kW
Engine startManual/electric
Outlets2 x Schuko 230 V
Special functionsGasoline, Protective housing, Parallel connection, ATS output, Economy mode

1299 € 1199 €

Pure sine wave

The built-in electronic unit with microprocessor control monitors the operation of the generator and provides a stable output voltage of 230V 50Hz sinusoidal form, which is suitable for the reliable operation of sensitive electronics.

Robust engine

The Könner & Söhnen reliable engine is characterized by increased durability, long and stable operation, and meets all European quality standards, including EURO V.

Economy mode

The ergonomic control panel is equipped with a fuel economy mode switch. This mode reduces fuel consumption by up to 50% at small loads due to lower engine revolutions.


KS ATS 4/25 Gasoline
Peak power demandin standby mode: 0.36 W, in operating mode: 1.2 W W
Power (230V)5.75 (11.5) kW
Current (max) 230 V25(50) A
Power 400V13 kW
Current (max) 400 V25 A
Working environmentfrom -10°C to +55°C; humidity: ⩽60%
Storage environmentfrom -10°C to +70°C; humidity: ⩽60%
Insulation classAC1.0KV / 1min 1mA
Maximum battery charging current from the built-in power supply, A2
Control cable length5 m
IP protection classIP41
Net dimensions (LxWxH)250 х 140 х 320 mm
Gross dimensions (LxWxH)325 х 200 х 405 mm
Net weight6.0 kg
Gross weight6.5 kg
EAN code4260405364787

The KS ATS 4/25 Gasoline ATS (Automatic Transfer Switch) unit from the German brand “Könner & Söhnen” automatically starts the generator and transfers load to it when the main power source is turned off and automatically stops the generator when the central power supply is restored. It is compatible with gasoline inverter generators that are equipped with a 8-pin connector for an automatic transfer switch unit (ATS input). The ATS unit has a PLC for programming the engine starting time after power outage, the engine warm-up time before connecting power consumers as well as for signaling errors. It has a generator emergency stop button. The ATS unit can operate both in automatic and in manual mode. 


  • Automatic/manual operation
  • Programming of engine starting time after power outage
  • Programming of engine warm-up time before connecting to consumer
  • Setting of starter operation time
  • Engine performance monitoring
  • Battery charging when the generator is off

The KS ATS 4/25 Gasoline ATS unit is compatible with Könner & Söhnen gasoline inverter generators KS 4000iE S, KS 4100iE, KS 6000iE S, KS 8100iE ATSR with integrated 8-pin ATS connector.

The ATS (Automatic Transfer Switch) unit automatically starts the generator and transfers load to it when the main power supply is disconnected and automatically stops the generator when the central power supply is restored. The ATS output features an 8-pin connector for connecting the ATS unit KS ATS 4/25 Gasoline. 

6-in-1 multifunction LED display

The 6-in-1 multifunction LED display has the following indicators: load indicator, fuel level indicator, hour meter, voltage, frequency, oil level indicator, overload indicator, working mode indicator.

Ergonomic control panel

Convenient location of all functions: working mode indicator, overload and short circuit protection, low oil level sensor, Reset button to reset the control system and restore voltage supply, connector for parallel connection of generators, typical 12 V car socket for a wide range of car devices, gadgets and battery charging, 230 V sockets and grounding terminal.

Low noise level

Thanks to a special protective housing, which provides a minimum noise level of 66 dB, the operation of the device will be as comfortable as possible and will not disturb others.

High quality alternator

Könner & Söhnen inverter generators are equipped with a robust brushless alternator with 100% copper winding. The high-end compact permanent magnet alternator is housed in a plastic casing and can withstand maximum loads without any damage to ensure long-term and reliable operation of the generator set.

Parallel connection

Cable (100% cooper)AWG 2.08 mm2
Maximum power7 kW
Cable length2х80 cm
Outlets1 x Schuko 230 V, 1 x CEE 230 V 32 A
Circuit breaker+
Net weight1.36 kg
Gross weight1.60 kg
EAN code4260405362530

KS PU1 generator parallel unit from Könner & Söhnen allows to increase the total output power of generators by connecting two inverter generators together. Parallel connection of any two generator models provides output power equal to the combined rated powers of these models. At the same time, parallel connection of generators entails a power loss of 0.2 kW of the aggregate rated power which can be obtained.

It is suitable for all Könner & Söhnen inverter generators, except for the KS 8100 series models (KS 8100iE, KS 8100iEG, KS 8100iE ATSR, KS 8100iEG ATSR).

Parallel connection ensures insreased power. Using a parallel connection device connected to a special socket on the generator, you can pair the generators and connect devices with greater power. It is suitable for all Könner & Söhnen inverter generators, except for the KS 8100 series models (KS 8100iE, KS 8100iEG, KS 8100iE ATSR, KS 8100iEG ATSR).

Transportation kit

Könner & Söhnen Inverter generators are equipped with a transport system for easy movement. Two wheels and a handle that lifts when the generator is moved ensure comfortable transportation and mobility.

Additional accessories

Included: screw-driver, candle key.

Max power, kW
Nominal power, kW
Frequency, Hz
Current (max), А
2 x Schuko 230 V
Engine start
Fuel tank volume, l
Avg. working time (power 50%), h***
LED display
Load, fuel level, voltage, frequency, working hours; overload indicator, voltage indicator, oil level indicator.
Noise level Lpa (7m)/Lwa, dB
Power output DC, V/А
Engine model
KS 240i
Engine cylinder volume, cm3
Engine type
Gasoline powered one-cylinder, four-stroke air-cooled
Engine power, hp
Possibility of parallel connection
Output for ATS
Crank case volume, l
Accumulator, A·h
Protection class
Alternator winding
Net dimensions (LxWxH), mm
Gross dimensions (LxWxH), mm
Net weight, kg
Gross weight, kg
EAN code

Assembled in PRC.

*** Fuel consumption depends on many factors, such as load, fuel quality, season, altitude, technical condition of the generator.

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