Siemens LMV, Autoflame, Honeywell SLATE, and Fireye Nexus are linkageless systems. Each drives fuel and air with separate actuators instead of mechanical linkage, and each combines flame safeguard and fuel-air ratio control. They differ in how they're configured, how they trim, and how they handle multiple boilers.
Siemens LMV. The LMV3 is the compact series for smaller burners. The LMV5 series handles larger systems with up to six actuators. Most LMV51 models include a built-in load controller, and LMV52 models add O2 trim. Gas valve proving is built in.
Autoflame. Autoflame's Micro Modulation (MM) controllers combine flame safeguard, valve proving, and fuel-air ratio control. Paired with Autoflame's exhaust gas analyzer (EGA), which measures O2, CO2, and CO, the system can trim combustion on three parameters and store operating data.
Honeywell SLATE. SLATE is built from DIN-rail modules rather than a single controller. A system is assembled from the modules the application needs, such as burner control, fuel-air ratio, and limits. The fuel-air ratio module controls up to four actuators and two variable frequency drives. The modular setup suits custom or multi-burner equipment and takes more engineering up front.
Fireye Nexus NXF4000. An integrated controller with flame safeguard and parallel positioning. Each fuel profile can use up to four servos, an add-on card controls up to two VFDs, and valve proving and O2 trim are available. Peer-to-peer sequencing is built in for up to six boilers, and Fireye's plant master controls up to eight units.
Choosing one. Matching the system already in the plant simplifies spare parts and training. For boilers that run year-round, O2 trim can reduce fuel use. Multi-boiler plants need lead/lag sequencing, and connecting to a building automation system or SCADA requires Modbus or a gateway. Also check who can commission the system locally, since results depend on how it's set up.
Related reading: O2 Trim Systems, Flame Safeguard Upgrades and Ventless Gas Trains and Valve Proving. See all of our services on the What We Do page.
Planning a retrofit, or have a system that's drifted out of tune? Send us your burner and control details. Request service or email service@combustionspecialists.com.
