Loss Prevention Hot Topics

Restoring Your Facility after a Power Outage

Whenever there are interruptions to your supply of electrical power, there is a chance you may incur electrical losses. Because there are so many ways for your power to go out, it is important to think ahead before resuming normal operations.

How well a facility’s electrical distribution system deals with interruptions depends to some degree on the overall quality of the system. In addition to infrastructure, such as power lines, consider the condition of your electrical equipment and whether protection is in place against electrical surges.

It would be reasonable to expect issues with the quality of your electrical power supply right before an interruption occurs. These issues can also happen shortly after the electrical power supply is restored. Some of the concerns include voltage sags and electrical surges due to system-wide load conditions and how your utility switches power. Even though we know this may not be practical in many cases, you should delay the full restoration of facility services until a stable power supply is available.

Your facility should be in a “shut down mode” before the utility returns power to your incoming line. Following a power interruption, turn off electrical equipment within the facility where reasonably possible. This minimizes the chance that your facility will suddenly place an abnormal high power demand on the facility’s electrical distribution system and the electrical system grid.

While most large electrical motors, such as central HVAC systems, may require a manual restart by design, there may be many small motors (as are found in window AC units) where this is not the case. If left on, these could try to restart all at the same time when power is restored due to the demand for cooling in the facility. This can present a significant load on the facility’s electrical distribution system, so make sure you check all such electrical appliances to ensure they are off before the electricity returns.

Once power resumes, switch on electrical equipment in an organized fashion. We recommend that lights be turned on first.  If power quality problems arise, an electrical light will dim or flicker, indicating a system issue. If the lights are stable, return smaller loads to service first and observe their operation before moving on to larger equipment.

If at some point a fuse blows or a circuit breaker trips, a qualified individual should investigate the cause prior to replacing the fuse or resetting the breaker. Failing to do so may result in greater damage if the power interruption caused an electrical system fault.

We also recommend that you ask laypeople to use only normal operating controls and switches to turn electrical power off and on.  This could be the light switch inside a classroom or the on/off buttons on an AC unit or pump.  You should use the controls directly switching the power to the device or system.  Only qualified individuals should operate main or branch circuit breakers that feed substantial portions of facility’s electrical distribution system.

If you have questions about this Hot Topic, please contact your Loss Prevention Consultant.