By Jeff Crane, P.E., LEED® AP
Published in the August 2007 issue of Today’s Facility Manager
It may be summer vacation for kids, but school is always in session for facility managers (fms). While the children sleep late, play games, go swimming, watch cartoons, and complain about being bored, most fms are actively enrolled at the “School of Hard Knocks.” Daily lessons include advanced studies on human comfort, restroom etiquette, humidity control, reptile/amphibian/insect intruders, copy machine acrobatics, mold and mildew, vending machine boxing, sink holes, and even fire alarms.
For today’s lesson, let’s talk about electrical systems and some of the most common havoc wreakers. Lightning, car accidents, critters, and subcontractors seem to be familiar suspects when the lights go out, but are they always to blame? Rolling blackouts, ice/snow storms, equipment failures, high winds, tree entanglements, circuit overloads and human errors can also bring an otherwise normal day (is there such a thing in any season?) to a grinding halt.
Given the above list, it’s probably advisable to minimize the length of above ground power lines when planning new facilities. Utilities folks would argue that above ground power lines are much easier to troubleshoot and therefore easier/faster to repair. They’re also less expensive to install. However, underground lines are less susceptible to many common disruptions and feature the added benefit of being invisible to visitors.
For existing facilities, fms can evaluate the types of power incidents that might be (or have been) encountered most frequently. If you are new to a particular facility or have questions about the reliability of your community’s electrical service, inquiries to the local utility and other corporate neighbors might prove useful.
It’s also wise to understand specifically how power arrives at your building. The local utility rep (with a little help from widely available satellite imagery) should be able to clarify electricity routing (above and/or underground) between the grid and your facility.
These conversations can also help identify other facilities served by the circuit. When you know which neighbors are served by the same power substation, a few quick phone calls during an outage can help diagnose the extent of the problem (even if you can’t reach beyond the utility’s voicemail labyrinth).
Inside the building, many fms rely on transient voltage surge suppression (TVSS) to handle occasional, short duration electrical anomalies. TVSS can be applied at the main switch gear and/or on individual loads, but it’s important to note and emphasize the letter “T” in TVSS. These devices are designed to isolate and correct TRANSIENT (i.e. very short duration) power issues. They are not designed to correct an extended phase loss (losing one or two phases of a three phase power service) or long-term over-voltage condition that could result in significant damage to motors, lighting, or computers. TVSS devices also have a finite life and will require replacement depending on how frequently they are required to work.
For a more thorough explanation of TVSS and exciting discussions about Metal Oxide Varistors (MOV), a quick search for TVSS on www.wikipedia.org or the IEEE (Institute of Electrical and Electronics Engineers) Web site (www.ieee.org) will provide a wealth of knowledge. Guidance can also be found through various electrical OEMs such as Liebert (www.liebert.com), Siemens (www.siemens.com), or Square D (www.squared.com).
In addition to an effective TVSS strategy, fms should consider critical loads such as data centers. Many use uninterruptible power supplies (UPS) in maintaining electricity to mission critical computer equipment.
Some UPS are designed to monitor and correct every aspect of power quality and assure that equipment downstream never experiences anomalies. Other UPS don’t have this level of sophistication and basically serve as a battery bank when power is lost. Fms with responsibility for data centers should, in coordination with IT management, have a very thorough understanding of their UPS specifications and recognize exactly what situations can and can not be mitigated.
Facilities with emergency generators have an additional level of protection against power outages, but just like the UPS, all generator systems aren’t identically equipped. Some transfer switches (the device that switches electricity between normal and emergency power) are designed to activate only with a complete loss of power. Others only recognize phase loss, over-voltage, or other power quality issues. It’s important to understand how these systems operate and confirm they’re sufficient.
In researching existing capabilities, many operation and maintenance manuals can be found online. It might also be wise to meet with manufacturers’ representatives or a licensed electrical engineer to talk through various scenarios and determine how each piece of equipment should function. Again, it’s important to involve IT management in these conversations, since they’re usually ultimately responsible for sensitive computer gear (and tend to have generous budgets).
Finally, fms with—and without—state of the art protection from electrical malfunctions should consider developing an effective alarm strategy. Quick identification of problems and communication to folks capable of taking corrective actions can be priceless. For example, in a sustained over-voltage or phase loss condition (that a TVSS isn’t designed to correct), alarms generated by a UPS or an independent power monitoring device could be immediately dispatched to a digital pager or PDA. Facilities and IT staff could quickly respond and assess the situation, and when necessary, conduct manual shutdowns (transferring to emergency power in buildings with generators). Tabletop simulations and live after hours drills can be excellent tools for talking or working through various situations and making sure everyone understands the role of their equipment and staff members.
Class is adjourned. Enjoy the rest of the summer! If you hear kids complaining about being bored, help them understand the origin of “summer vacation” and warn them that since so few kids live on farms today, adults in your community and around the world are conspiring to bring back year-round school!
Crane is a mechanical engineer and regional property manager with Childress Klein Properties, a leading real estate developer and property management services provider in the Southeast. Want to share some of your power management suggestions? Crane is always interested in reader feedback!
Please note: The views stated in this month’s FM Frequency do not necessarily reflect the opinions of TFM or the other entities represented in the magazine.