Douglas H. Sandberg


There are two demons lurking in your legacy emergency power supply system (EPSS). They are waiting for the right time to strike and render your mission-critical system useless. The demons are known as technological advancement and market demands.

The EPSS comprises two main groups of components: the mechanical assemblies and the electronic controls. The mechanical assemblies, including engines, fuel system, exhaust system, fresh air intake system, etc. are durable and robust and don’t change much over time. With a comprehensive maintenance program, these components will live a long and happy life.

The electronic controls are another story. Intel co-founder Gordon Moore made this prophetic observation in 1965, when there were approximately 60 devices on a chip, regarding the pace of semiconductor technology “The number of transistors and resistors on a chip doubles every 18 months.”  Four decades later, Intel placed 1.7 billion transistors on its Itanium chip.

To put this issue in perspective, consider the laptop or PC you purchased for your college freshman 6 months ago. Compare the price and specifications against the packages available now. You can probably purchase much more for much less now. The electronic controls in your EPSS are no different. As a result, manufacturers are constantly designing new control platforms with enhanced capabilities to satisfy market demands for new technology.

As new solutions become the “state of the art” and demand increases; older platforms fade into obsolescence. At some point, vendors phase out legacy products, and they become difficult, if not impossible, to find. This is not the situation you want to be in at 3 a.m. when a key component has failed.

What then constitutes end of life for the emergency power supply system? There is no definitive answer. To determine the health of your system, close collaboration with design professionals, manufacturers, and your service provider is necessary. It is also logical to budget capex funds for replacement at some point in time.

Another Option

What if you could revitalize your legacy EPSS without disrupting your facility or losing emergency power while saving money in the bargain?

Today there are alternatives to replacing obsolete switch gear. Manufacturer’s modernization programs may replicate controls schemes and operator interfaces using state-of-the-art technology. It is also sometimes possible to make changes to the base configuration of legacy systems. You might be surprised by the possibilities if you take time to evaluate the mission of your facility and determine what enhancements you would make if you had your way.

Upgrading basic controls and operator interface components represents roughly 50 percent of the cost of replacing all the gear. The value proposition becomes much more attractive, however, when you add the following collateral expenses:

  • Unhooking the old gear and rewiring the new
  • Maneuvering a large assembly through a confined environment
  • Disruptions to your facility
  • Temporary standby power while the transition is taking place
Once you add the cost of these activities to the replacement cost of the hardware, the value proposition for an upgrade looks a lot more attractive (typically 25 to 30% the cost of replacement).

Depending on the hardware specifications and configuration, a variety of actions may be taken as part of the gear renewal.

Replacing doors and pans is the most basic improvement. This entails replicating the existing control components (pans) and operator interface (doors) with current technology. This is also an excellent opportunity to upgrade capability. For example, basic control and metering can be replaced with power measurement/management capability, control switches can be replaced with operator interface terminals, and monitoring may be enhanced or added.

Over time, the facility’s mission may have evolved. This is also an opportunity to re-configure system capacity and flexibility. For example, additional capacity (engine generators/bus work) may be added. These changes may be physically limited but worthy of exploration.

Given the increasing influence of NFPA 70E Standard for Electrical Safety in the Workplace, this is also an ideal time to consider the addition of concurrent maintainability to your legacy EPSS. The emphasis on arc flash hazards mandates that systems must be able to be electrically secured for maintenance. In other words, components must be able to be de-energized, locked and tagged out and personnel placed in a safe environment while performing maintenance routines without impact to availability to serve critical loads.

Your business depends on mission critical systems. While the iron remains durable over many years, system controls are subject to displacement with newer technology. There are minimally invasive alternatives available, which allow you to take advantage on new technology without the expense and disruption of replacement.