It’s a tricky and dirty electric world out there. And it’s getting more challenging with every watt hour.

At its foundation, security systems depend on batteries, transformers and power supplies. Used together they convert incoming 110/120-volt electrical service to 12- or 24-volt needs. The batteries provide backup in the event of a power failure. The power supply unit transforms the current and charges the battery.

Some newer units are more flexible. Among advancements, says Alan Forman, president of Altronix Corp., Brooklyn, N.Y., are wall-mount, rack-mount and outdoor power supplies, as well as units with multiple voltage outputs that operate simultaneously.

Power supplies go beyond keeping things going. Overload protection includes built-in circuitry to monitor and shut down the system in an overload situation. Transient protection aims at insulating the gear being powered from electrical fluctuations. Features continue to be added to power supplies, often to help installers, for more accurate maintenance and for better identification of trouble.

There is mathematics involved in power supplies. When installing any new fire, security, video or access control system, one of the first and most important considerations is power demand. Knowing this allows efficient and cost-effective matching of power supply to the system requirements. The same is true when a new device is added to an existing system. Will the system’s power supply be able to handle the additional power requirements?

The following equation is a helpful tool to determine what the total power demand of a system will be:
• Power (in Watts) = Current (in Amps) x Voltage (in Volts).
• VA is power in Watts described for AC systems. 100 VA equals 100 Watts.
To determine the power requirements for a system, add the total Amps required by each device in the installation and multiply by the voltage.

There also are compliance issues involved in power supplies. For instance, a unit from DMP is a power limited, switching power supply that meets UL, CSFM, NFPA and FCC compliance standards. Another example: a switching power supply from Highpower Security Products has selectable 12 or 24 VDC, 2 Amp output integrated with battery backup guarding against electrical failure.

When it comes to batteries, lead acid batteries are used by security installers for backup power needs because of their good charging characteristics and the memory immunity associated with repeated charging. When float charged, they typically last five years, according to Honeywell Power Products. Battery recovery time once AC power is restored varies greatly depending on several factors – charge current, age of the battery and temperature of the battery, just to name a few. Security power supplies do not have a time requirement for full recovery like fire-rated power supplies, so the recharge time for a security power supply could be longer.

Specific to life safety, there may also be a need for auxiliary power supplies.

One example is a system handled by FCS (Future Computer Systems), a Jacksonville, Fla.-based low-voltage systems dealer, which helped solve the fire protection challenges of a new \$35 million Samsonite distribution facility. Known for its vast portfolio of travel-oriented products sold worldwide, Samsonite strategically locates its warehouse facilities for easy distribution. When Samsonite officials decided to construct a one-million square foot distribution facility in Jacksonville, they turned to local dealer, FCS, for a sizable, high-tech fire alarm solution.

Using Fire-Lite’s fire alarm control panel at the head end, FCS designed a system capable of supporting a large number of notification devices as well as the power to sustain them. “What made this panel perfect for this application is that it provides many ways to drive and synchronize power supplies,” said FCS chief executive officer (CEO), Robert Olson. “This project required 10 auxiliary power supplies to power the 250-plus horn-strobe devices in this million-square-foot facility. And all are driven by that single fire panel.”

Networking, the Internet and fast-tracking of security video also impact power supplies. Units now can handle a larger group of cameras and Power over Ethernet (PoE) units; for instance, they can power video and access control edge devices.

When it comes to security video, protection units are reflecting the proliferation of cameras. For example, NAPCO’s Platinum Power now includes AC power supplies for 4 to 16 cameras, DC power supplies for 4 or 8 cameras, high-current power supplies/chargers, timers, relay modules, chargers, distribution boards and access power controllers.

There also are advances that can help in retrofits. New Notification Appliance Circuit (NAC) Expander Power Supplies have a resister compare feature, says Gene Pecora, general manager of Honeywell Power Products, Northford, Conn. “There is also more information from the trouble on circuit indicator light to differentiate temporary trouble.” On the video side, a rack-mounted power supply, Pecora reports, can be set at 28 volts to compensate for wire loss on long runs of a group of four cameras.

Network devices are just as susceptible to power problems as traditional security gear. Routers, switches, hubs, and cable/DSL adapters have specific power needs. So in certain situations, video or alarm signals and device communications can be lost due to power problems along the signal path.

There is news on the PoE front. IEEE recently approved a new amendment to IEEE Standard 802.3, which covers Ethernet organizationally specific type, length, values (TLVs). “IEEE 802.3bc is a very important new standard, because it enables advanced features in several other new and forthcoming standards,” says Wael William Diab, vice chair of IEEE 802.3 Working Group and chair of the IEEE 802.3 Maintenance Task Force that developed IEEE 802.3bc.

“802.3bc enables IEEE 802.3at’s enhanced power-management features. Another standard, IEEE P802.3az, which is currently in development, is currently planning to use 802.3bc for its enhanced power-saving modes,” he relates. The final, edited version of the standard will be available soon.

## Uninterruptible Power Supplies

In a security world dominated by computer and communications gear, as well as with systems that would lose their programmed-in routines in a power outage or lightning strike, uninterruptible power systems also play an important role. A UPS combines a power supply, backup battery and built-ins so security devices continuously have power during a set period of time. There are standby, active and online UPS units.

Companies ranging from Furman Sound to American Power Conversion and Tripp Lite, as well as traditional security system power supply firms report strong sales in UPS equipment. Console makers also can bundle in UPS. For example, Winsted now offers a number of UPS systems, under or above their consoles. This summer, Para Systems, a provider of comprehensive power protection solutions, inked a marketing and sales agreement with General Electric’s Power Quality division centering on UPS gear.

Adding to its line of UPS solutions, Altronix has a new outdoor model housed in a NEMA rated weather-resistant enclosure to handle 12VDC and 24VAC outdoor cameras during normal, brownout and power fail conditions. The unit is “in proximity of the camera locations and assures that all cameras run without a glitch,” Forman describes. It includes a built-in charger for sealed lead acid or gel-type batteries along with supervisory status indicators, AC fail and low-battery reporting.

Standby backup offline devices provide direct connection between utility power and the protected equipment. If power fails, the UPS will switch on the battery backup, which is connected through an inverter that converts the DC power from the battery into 60-hertz AC for a short period of time. Line interactive or LI UPS have power line monitoring to handle brown outs. Online types of UPS boast an electrical firewall between the connected devices and utility power service.

UPS units can also go underground. From Solis Energy, the In-Ground UPS aims at gang switched light poles that typically do not get power during the day and in areas where utility poles are overcrowded or undersized and cannot support an additional attached power source. Also, since the battery enclosure is out of sight, the In-Ground UPS is more aesthetically pleasing, and doesn’t detract from decorative street lights that weren’t typically built to support an external power source. City of Apopka, Information Technology director Don Kahrs comments, “Our street lights are set up as gang switched, meaning they all turn on at the same time, which was only from dusk to dawn. In-ground UPS allows us to power the radios on our street lights any time day or night, which will keep our city’s WiFi network up and running anytime.”

## Generators

Then there are backup power generators, many of which now automatically switch from the public grid to self-created electricity to keep security systems, computers and lights going. There are commercial and – more recently – residential generators, which go beyond the fishing camp versions. Some security dealers, integrators and home systems installers are adding these generators to their offerings.

According to the Electricity Advisory Committee of the U.S. Department of Energy, the current U.S. electric power delivery system infrastructure will be unable to ensure a reliable, cost-effective, secure and environmentally sustainable supply of electricity into the future. As severe weather continues to strike and blackouts become more common, businesses and homeowners will need to consider alternative solutions. In homes, the proliferation of personal computers, iPods, cell phones, game consoles and big screen TVs is the fastest-growing source of power demand in the world. Americans boast 25 consumer electronic products in every household, compared with just three in 1980.

At the 2009 International Builders’ Show, the housing industry’s largest annual trade show and exhibition, one of the National Association of Home Builders’ exhibitors was Briggs & Stratton, which introduced a line of energy-efficient automatic standby generator systems under the General Electric brand. According to Harold Redman, president of Briggs & Stratton Home Power Products, “Power outages have forced more than 13 million people to leave their homes this past year, costing them more than \$10.6 billion during hurricane season alone.”

According to Tom Oliver, Sr., president and owner of Security Electronics, Pass Christian, Miss., “Virtually everyone is interested in installing [a standby generator] in their home.” Despite the fact that price is a concern for many homeowners, standby generators still account for 50 percent of his company’s annual business – and for good reason: prices have come down and there are more choices than ever. Over the past three years, for example, the cost of a standby generator dropped 13 percent, making it an attractive, affordable option for homeowners anxious to protect the investments they have made in their homes. So a standby generator shouldn’t be considered an add-on; it’s a value proposition.

Although rapid growth has occurred in the standby category, recent research confirms that consumers still have a high degree of purchase interest in standby generators that are more energy-efficient. In a recent Better Homes & Gardens study, half of the consumers surveyed paid more money for an energy-efficient product in the past 12 months.

Generac Power Systems created a dealer program to ensure the proper installation of automatic standby generators. “While the average do-it-yourselfer has a basic understanding of an automatic standby generator, we recommend the installation to be completed by a licensed electrical professional to ensure warranty eligibility,” says Dave Rademaker, installation program manager.

The installation package includes consultation and planning; job site preparation; generator placement; basic electrical installation which includes installation of transfer switch within two feet of main electrical panel and 30 feet of the generator and connection of selected circuits determined by consultation; basic materials; testing and startup; job site cleanup; and final walk-through and demonstration.

Speaking of home applications, power conditioners take the noise out of plugged-in home entertainment systems, too. According to Furman Sound, Petaluma, Calif., a good power conditioner filters and cleans incoming AC power and dramatically improves equipment’s performance. Audio sounds better and pictures look cleaner.

The future of power holds a lot of off-the-grid excitement for both commercial and residential applications. Some of that future, such as solar power, is already here. Emergency telephones and other outdoor security devices can drive off of pole-mounted solar panels. In Japan, Sharp Corp. has residential solar power generation systems installed on small roofs and on roofs with complex shapes, where installation has been difficult with conventional systems.

## The Future Is Brown & Black

Power outages fall into three categories depending on duration and effect.

A dropout is a momentary (milliseconds to seconds) loss of power typically caused by a temporary fault on a power line. Power is quickly (and sometimes automatically) restored once the fault is cleared.

A brownout is a drop in voltage in an electrical power supply, so named because it typically causes lights to dim. Systems supplied with three-phase electric power also suffer brownouts if one or more phases are absent, at reduced voltage, or incorrectly phased. Such malfunctions are particularly damaging to electric motors.

A blackout refers to the total loss of power to an area and is the most severe form of power outage that can occur. Blackouts which result from or result in power stations tripping are particularly difficult to recover from quickly. Outages may last from a few hours to a few weeks depending on the nature of the blackout and the configuration of the electrical network.

The Electric Power Research Institute urges use of power control devices employing advanced sensors to coordinate the grid. Others advocate greater use of electronically controlled high-voltage direct current firebreaks to prevent disturbances from cascading across AC lines in a wide area grid.

## PTCs versus Fuses

Positive-temperature-coefficient devices (PTCs) act as a type of circuit breaker; the resistance increases as the PTC threshold temperature is exceeded due to the load current passing through the device. This causes high resistance which opens the circuit protecting the device in the event of an over-current condition. Unlike fuses, ambient temperature plays a role in how long it will be before a PTC reacts to over-current. For this reason, careful consideration should be given to when PTCs are used for equipment protection, according to Preferred Power Products.

A PTC is appropriate for battery protection as most battery shorts are heavy shorts quickly tripping the PTC. The PTC is best for devices that can tolerate high current for a substantial amount of time, such as batteries.

Because PTCs are slow acting and have a less accurate trip threshold, the PTC may not protect security cameras as reliably as a fast acting fuse. Because PTCs need to cool down to reset and will not do so if the over-current condition is not corrected, a service call will probably be needed to address the failure.

## How a Home Standby System Works

When the utility power fails, a backup generator transfers the power source. According to Cummins Onan, there are six basic steps.
1. The panel monitors the voltage coming from the utility.
2. It senses when the utility power drops below an acceptable level, and sends a signal to start the generator set.
3. It automatically disconnects the utility power from the electrical circuits in a home or business and reconnects them to the generator.
4. The unit continues to supply electrical power until utility power is restored.
5. When utility power is restored, the system automatically disconnects the generator set and reconnects the utility power.
6. The system automatically re-sets itself and is ready for the next power outage.

A standby system has two major components: a generator set to produce the power needed to run essential home, security or business systems and an automatic transfer switch that immediately senses when utility power has been interrupted, transferring responsibility to the generator.