Gas Engine and AFR Solutions

Air Fuel Ratio (AFR) control system from APE is a comprehensive solution for generating sets driven by gas engines. The system consists of several specific control and interface modules:

  • InteliSys NT AFR – Highly configurable, expandable genset controller with built-in PLC functions
  • ECON-3 – digital speed governor
  • I-Step – interface to stepper motor actuator controlling variable gas/air mixer
  • DENOX-20 – anti-knocking system with 20 channels, (marketed as DETCON-20 by MOTORTECH)
  • I/O modules – inputs and outputs for various analog and binary signals. Optimal set of modules depends on engine size and number of cylinders.

Control modules are fully integrated via CAN bus. The key parameters from all modules are accessible via main display on InteliSys.

All key algorithms are field proven on many installations:

  • AFR algorithm keeps air to fuel ratio on the optimal level, ensuring the right exhaust gas emissions with minimum of AFR readjusting
  • Knocking detection protect engine from severe damage


  • Fully integrated system – all parts and parameters are monitored and accessible from single point.
  • Simple and robust AFR algorithm does not require lambda sensor (lean burn solution).
  • Solution for various types of gases – natural gas, landfill gas, biogas, with possible utilization of the CH4 content of the gas
  • Build-in PLC functions and high configurability of IS-NT enables to build the system exactly satisfying the customer needs.
  • Gen-set performance log stored in IS-NT is invaluable tool for troubleshooting
  • Excellent remote monitoring features backed by sophisticated PC programs are ready for fleet owners. They help to plan maintenance and trace production of heat and energy for each genset from the fleet.

Types of AFR Solutions

Lean Burn Solutions
Stoichiometric Solutions

Need help or have a question?

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