This advanced microprocessor is the heart of effective combustion control, built to a bespoke Dunphy design, the system ensures optimum combustion efficiency by precision management of air and fuel valves. The Ratiotronic responds to boiler load and performance changes through integral PID loops. The Ratiotronic can communicate with remote systems using the Modbus protocol to provide all key burner/boiler information and control. This protocol can also be converted to a variety of other common protocols such as Profibus and BACnet.

Ratiotronic systems can be fitted to all Dunphy single and multi-fuel burners enabling consistent operation on gas below 3% O2 across all operating loads; at less than 2% at high fire and less than 3% low fire.

• Modulation control can be automatic or set to a fixed firing rate
• Up to 4 fuel – air profiles
• User defined fixed or variable set points
• Designed for easy retrofit
• CANbus links
• Multiple boiler sequencing
• Local or remote operation
• Monitors CO, NOx and SOx

The membrane keypad and plain text message panel provides a wide range of control and command options.

Benefits include:

• Fuel saving of up to 10% over conventional mechanical linkage-based systems
• Flame safeguard and fuel air ratio controller all-in-one
• Associated cost savings & CO2 emissions reductions
• Improved turndown
• Oxygen and CO trim options
• Setback option allows lower set points during low periods of demand
• Flexibility to address most burner applications
• Conventional & bio/waste fuel firing
• Reduced boiler maintenance
• Prolonged boiler life
• Interfacing to SCADA and other third-party systems using communication protocols such as Modbus and Profibus
• A range of ancillary devices including CANbus servo motors and self-checking boiler temperature & pressure sensors

The LMV burner management system has the burner control, electronic air-fuel ratio control and gas valve proving integrated in its base unit. Optionally, the system can be equipped with a load controller, VSD control and O2 combustion optimization. The load controller features an electronic safety limit thermostat.

The LMV52.4 also offers a temperature-compensated flue gas recirculation function for “super” low NOx applications, along with specific O2 control functions for fibre mesh burners.

Load control is in the form of a PID temperature/pressure controller featuring an algorithm for cold start of hot water or steam boilers, thus ensuring low wear and tear. Furthermore, the load controller is equipped with an electronic safety limit thermostat. Continuous operation poses no problem to the LMV5 when used in conjunction with universal infrared flame detectors, UV flame detectors or ionisation probes. Separate inputs and outputs for oil-fired or gas-fired operation deliver accurate diagnostics of the connected components and facilitate dual-fuel operation with no need for additional relay changeover.

The LMV burner management system not only simplifies burner design but also makes the production process, mounting and service work more efficient. The complex linkage required with mechanical air-fuel ratio control is no longer needed and flexibility in terms of mounting is considerably increased.

The compact base unit can be fitted directly in or on the burner or, using a powerful data bus, in a control panel. Since mechanical linkage is no longer required, electronic air-fuel ratio control offers a new kind of flexibility when it comes to adjusting the actuators. Also, system integration of functions cuts mounting and commissioning costs.

Benefits include:

• Gas valve proving
• Optional load controller
• Modbus communication
• Super-Low-NOx- Application
• Excellent price-performance ratio
• Combustion optimization via O2 trim control
• Total of 20 languages available
• Optimised configuration by the user
• Straightforward installation and maintenance
• Adjustable safety times according to EN746
• Extremely versatile for a wide range of industrial applications
• Connection of external flame safeguards
• LMV5 system suitable up to SIL3

A burner management system which can be adjusted for a wide range of combustion conditions by setting a variety of parameters. Starting with and without a pilot, the burner can be set separately for oil and gas. Starting without pre-purge is possible in accordance with EN676.

The ETAMATIC is available with 4 three-point step outputs or with 3 three-point step outputs and a continuous output (such as for speed control).
On request the ETAMATIC undertakes the firing rate control of the burner. An internal firing rate controller allows up to two switchable set-points for temperature or pressure to be defined (e.g. for night-time reduction or heat-maintenance mode, external set-point shift, such as weather guidance, or start-up control), compare these with actual values and determine the burner firing rate position required to reach the set-points. The latter is then forwarded to the electronic assembly as the target value. The firing rate controller can be used as a fixed value or weather-guided controller.

The integrated valve leakage check can be run before ignition or a burner shutdown.

Start-up and operating hours counters count both the total start-ups and burner operating hours as well as for each operating mode (gas, oil) separately.

Benefits include:

• Compact burner control unit
• Failsafe electronic assembly with up to 4 actuators
• Connection to control technology (Modbus, Profibus, etc)
• Settings can be made graphically via PC
• Integrated valve leakage check
• External current correction (heating value or temperature compensation)
• SIL 3 confirmed
• Internal firing rate controller
• CO/O2 control for combustion optimisation
• Flame monitoring (optional)
• Mobile operating unit (optional)