PREPARING FOR AN ELECTRICAL POWER OUTAGE.

Summer can be synonymous with "blackouts." Is your facility ready for the next one?

BLACKOUT! The electric power supplying your facility is out. You knew it could happen for any number of reasons and at any time of the day or year. Suddenly you wish you had planned for this event that you knew would happen sooner or later, but there was always something just as important that needed to be done immediately. Now it is scramble time, and the lights are out!

Whew! Good thing that was just a bad dream. In fact, today seems like the perfect day to begin putting together a plan that will minimize the risk to your facility operations in the event of a power outage. But where do you start?

The first Step in preparing a blackout response plan is to become thoroughly familiar with the electrical distribution system layout and design in your facility. Still, most power systems are quite elaborate and complex, and it would be impractical to expect someone in your position to commit a system design to memory (not to mention dangerous). That is why having updated system documentation is so important for anyone designated to be responsible for operation of the power system, regardless of the size. If your one-line diagrams do not accurately reflect the present configuration of your system, then step number one of your plan is to get them updated.

An effective one-line diagram will clearly show how the main components of the electrical system are connected together, including redundant equipment and available spares. Details on equipment ratings are typically shown, and it is helpful to identify each major component with a unique name. In addition o showing the equipment identifier on the drawing, a permanent equipment label should be mounted onto the component itself. This greatly reduces the possibility of operating the Wrong piece of equipment during an emergency.

Once the design of the system is well documented and understood, it is important to identify critical loads that will require emergency power in the event of a power outage. Typically, emergency generation cannot be provided for all of the facility's loads, so you should define what equipment is absolutely essential during the outage. Once identified, these loads should be clearly marked on the one-line diagrams as being "emergency loads."

Ideally, all critical or emergency loads should be fed from common circuits, separate from non-emergency loads. Even though this might require that some equipment be rewired to other circuits, it will simplify supplying emergency power generation during an outage.

Once the emergency circuits have been established you will need to be careful that future loads added to these circuits fit the criteria of being "critical." Very often, new loads are added to any electric panel that might have an open circuit breaker, regardless of their importance. This results in an emergency panel being loaded with noncritical equipment for which emergency power generation during an outage is unnecessary.

Depending on the tolerance of your emergency loads for being without power for a given period of time, you might consider installing a permanent emergency generator dedicated to that equipment, rather than relying on portable generators that need to be hooked up after the power has gone out. It is imperative that the running load of each emergency circuit (measured in amperes) be known, to determine what size generator(s) will be required. Records of the kilowatt and voltage ratings of each generator needed should be readily available before the outage to expedite your response.

If portable generation is the best alternative for your facility but purchasing a standby unit is impractical, you might want to arrange a rental agreement with a dependable local vendor. Be sure to consider such things as the number of generators in stock, delivery, the guaranteed response time and services included if a generator has problems. Also, find out where you rank on their list of priority customers, because when the outage happens, everyone will be looking for rental generators.

Your staff need to plan how each generator will be connected during the emergency response time. Is it practical to install manual transfer switches near the emergency panels ahead of time, so that they are available to easily transfer the load to the generators? Are spare cables, properly sized for the load, stored with the emergency generator(s) to ensure the hook-up can be done quickly? Has the rotation of three-phase circuits been predetermined and labeled to ensure proper connection of the generator to the emergency loads? Do you have formal written procedures explaining how to connect each generator to its emergency loads?

And a large question: Is your staff adequately trained to do this work? If not, make arrangements with an experienced, reliable contractor to provide these services.

Your staff should develop testing procedures to ensure that the generators can indeed carry the emergency loads. Ideally, the generators should be tested under actualload conditions quarterly, but if this is not practical, at the very least each generator should be started up and run for approximately 45 minutes each month.

And don't forget the fuel! Make sure that each generator's fuel tank is full and that you know where and how to get fuel during the outage. Also, test your fuel for the presence of water. If your fuel is more than a year old, it should be replaced.

If your facility has computer loads or communications systems that use an uniterruptible power supply (UPS) to ride through short-term outages, you should develop procedures for having an orderly shutdown. Typically, a UPS will provide power for only a short period of time (15 to 60 minutes), which allows you to back up system and data files and bring the systems down. Preparing for this scenario now and performing practice runs will result in smooth sailing during an extended outage and help avoid lost data.

Probably the greatest cause of damage to equipment from a power outage is from the electrical surge that is thrust through the system when the power is restored. Fortunately, there is a way to protect against this phenomenon, but very few businesses take the steps needed to achieve this protection.

By installing a surge protection device (SPD) on the incom-ing electrical service of a build-ing, the damage caused by most externally generated surges (such as lightning or utility operations) can be greatly reduced. Further protection is achieved if SPDs are installed on distribution panels supplying critical or sensitive loads and locally at the equipment itself. This layering of SPDs throughout a facility is known as a "zone of protection" approach, and it is the most effective way of protecting your facility against electrical surges, including lightning.

All planning aside, what should you do when an outage actually occurs? Again, the answer lies in planning--in this case, having well-written, easily understood procedures that can be followed without confusion. We already mentioned the need for updated one-line diagrams, but make sure these are kept in a central location with all of the other necessary documentation. The same goes for the list of emergency generators and the loads to which they will be connected. Having written step-by-step procedures on how to connect each portable generator will save a great deal of time and stress, come crunch time.

As a part of this, to help your SPDs protect your equipment, have a written procedure for disconnecting or turning off loads (even though they are not running when the power is out). This will limit the equipment exposed to the surge when the power is restored. Start by simply turning electrical equipment to the "OFF" position. Depending on your system configuration, staff might need to open circuit breakers or disconnect switches to isolate equipment. Then, when power is restored, close circuit breakers and disconnect switches closest to the supply source first.

Next, close circuit breakers or turn on switches one at a time, working to ward the load, until all of the equipment is energized and power is restored. This procedure also should be followed when connecting portable emergency generators to critical loads. Make sure the circuit breakers and the disconnect switches in the circuit are open before the generator is started. Then, slowly close one breaker or switch at a time, working from the source (generator) to the load (equipment).

Careful planning is the key to successfully reducing risk to your facility caused by power interruption. Take steps today to protect your facility, and your residents, from the adverse effects of power interruption.

Matthew T. Glennon, PE, AVP, is a registered professional engineer with Hart ford Steam Boiler Electrical Loss Control, based in New Jersey. He, has more than 14 years of experience in electric power engineering and construction.

Editor's Note: This article is not meant to be exhaustive or complete, nor is it designed to replace information or instructions from the manufacturer of your equipment.