Factors Affecting BMS Lifespan
Burner Management Systems (BMS) are special types of control systems. They are used in installations where typically there are great environmental extremes. The fact that, after initial installation, most BMS function for prolonged periods of time without shutting off, means that the electronics generally undergo more severe operational conditions than those of other electronic systems.
A lot of BMS are installed outdoors in industrial settings like remote well sites or processing plants. The fluctuations in the environment place a significant amount of load on the operation of the equipment. Included among the environmental factors are ambient temperature, humidity, mechanical forces, pressure, acoustics, and vibration, which play a large part in degrading BMS located in these types of areas.
The type and quality of enclosure that holds the BMS electronics and other protection techniques plays a large part in the lifespan of the system. Enclosures can be selected that are more resilient to the effects of the environment, e.g. – using pre-cut foam enclosures protect better against the effect of humidity and water creep. Furthermore, circuit boards and display assemblies can be treated with conformal coating or RTV to protect them from moisture, temperature cycles and corrosion. The User Interface keypad fixed on the enclosure is also exposed to degradation from environmental factors.
The operational factors that affect BMS electronics are the applied current and voltage loads. Specifically, the load magnitudes, load rates, load range and duration of the loads affect the BMS lifespan.
Factors that affect the reliability of the solder interconnects of the electronics boards that make up the BMS include the interconnect dimensions, attaching methods, soldering methods, and stress conditions. In general, having more reliable components and manufacturing methodology drives up the production cost, so BMS manufacturers need to balance the need for reliability with that of acceptable product cost.
The fact that BMS are safety systems means that ongoing smooth operation is critical for safe industrial operations. Maintenance, timely replacement of parts and eventual upgrading the product is essential for continuous accident free operations. Using the precautionary principle for safety, it might be safer for industrial operators to err on the side of caution and replace their BMS before they become completely obsolete.
The lifetime of many of the electronic parts that make up the BMS is significantly smaller than that of the whole product. Parts become obsolete when they are no longer manufactured, either because demand has dropped to low enough levels that it is not practical for manufacturers to continue to make it, or because the material or technologies necessary to produce it are no longer available.
A BMS can be designed for a longer than usual life. An open design architecture and a parts obsolescence strategy helps in extending the BMS life. An open design architecture allows parts to be plugged in based on open standards in the original product ensuring that the product itself lasts a long time. Parts obsolescence strategies includes lifetime buys, substitution, redesign, using aftermarket sources, emulation, reclaim or uprating.
BMS manufacturers can buy and store enough parts to meet the system’s forecasted lifetime requirements. In part substitution, manufacturers use a different part with identical or similar form fit and function. When it comes to part redesign, the BMS may be upgraded to make use of newer parts. Parts may be sourced from aftermarket sources, as third parties continue to provide the part after the BMS manufacturer has obsoleted it. Manufacturers may select similar parts with identical form, fit, and function that are fabricated using newer technologies. They might reclaim the parts by salvaging them from other products. Finally, uprating is a parts mitigation strategy where parts outside their manufacturer specified environmental range (usually higher temperatures) substitutes the original.
Profire Energy offers PF2100 and PF3100 BMS solutions. To learn more about our products and solutions visit www.profireenergy.com.