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Surge Protectors, UPSs, and Generators

Surge Protectors, UPSs, and generators provide protection against one of the most common physical and environmental failures: electrical failures.

Surge Protectors

Surge Protectors protect equipment from damage due to electrical surges. They contain a circuit or fuse that is tripped during a power spike or surge, shorting the power or regulating it down to acceptable levels.

Uninterruptible Power Supplies

Uninterruptible Power Supplies (UPSs) provide temporary backup power in the event of a power outage. They may also “clean” the power, protecting against surges, spikes, and other forms of electrical faults.

UPS backup power is provided via batteries or fuel cells. UPSs provide power for a limited period of time, and can be used as a bridge to generator power; generators typically take a short period of time to start up and begin providing power.

Generators

Generators are designed to provide power for longer periods of time than UPSs, and will run as long as fuel is available. Sufficient fuel should be stored onsite for the period the generator is expected to provide power. Refueling strategies should consider a disaster’s effect on fuel supply and delivery.

Generators should not be placed in areas that may flood or otherwise be impacted by weather events. They also contain complex mechanics and should be tested and serviced regularly.

Learn by Example

Hurricane Katrina

Natural disasters such as the Katrina Hurricane of 2005 can teach us lessons on emergency preparedness, including the use of generators. Most generators in New Orleans, Louisiana, failed after power was lost. Many generators were in low areas that flooded; others failed due to poor maintenance.

Of the remaining generators that were located above floodwaters and properly maintained, most ran out of fuel. Gasoline and diesel were widely unavailable due to power outages, floods, and related loss and damage to infrastructure such as impassable roads.

Always place generators above potential floodwaters, and make every effort to place them in areas unlikely to be impacted by other natural disasters. Generators are complex and prone to failure: proactive maintenance should be regularly performed. Refueling generators can be highly problematic after a wide-scale natural disaster, so always consider this issue when designing fuel storage and generator refueling plans. This white paper discusses the problem in detail: https://web.archive.org/web/20130903101345/http://cumminspower.com/www/literature/technicalpapers/PT-7006-Standby-Katrina-en.pdf.

EMI

Electricity generates magnetism, so any electrical conductor emits Electromagnetic Interference (EMI). This includes circuits, power cables, network cables, and many others. Network cables that are poorly shielded or run too closely together may suffer crosstalk, where magnetism from one cable “crosses” over to another nearby cable. This primarily impacts the integrity (and may also affect the confidentiality) of network or voice data.

Crosstalk can be mitigated via proper network cable management. Never route power cables close to network cables. Network cable choice can also lower crosstalk: Unshielded Twisted Pair (UTP) cabling is far more susceptible than Shielded Twisted Pair (STP) or coaxial cable. Fiber optic cable uses light instead of electricity to transmit data and is not susceptible to EMI.

Note Years ago in the Plain Old Telephone Services (POTS) days when phone calls were transmitted over copper wires: did you ever have a phone conversation where you could hear another conversation from another phone call? It was often faint and hard to understand, but unmistakably there.

That is crosstalk: there was another phone cable that was too close or poorly shielded somewhere between you and the person you were speaking with. EMI jumped from that cable to yours, which you could hear as faint voices. In CISSP® terms, the integrity of your conversation was impacted (as well as the confidentiality of the other call).