Beyond lightning, power surges from brownouts, blackouts, grid switching and large equipment draw can wreak havoc with systems: Aftermarket surge suppression, recommended by fire marshals and NBFAA, can prevent most of the problems.
“Lightning storms rendered too many fire alarms inoperable, especially in multi-building complexes connected with cable,” said Whitney Crahen, the veteran Fire Protection Specialist who reviews fire alarm plans for the city of San Antonio, Texas. “When lightning hits, it can spread hundreds of feet until it finds the path of least resistance - all too often the highly conductive copper wiring that feeds into life safety alarm systems.”
Crahen’s solution has been to actively enforce NFPA 70 National Electric Code 800-30, which requires surge suppression devices on circuits that extend between buildings. “Proper surge protection for fire alarms is a requirement, and enforcing it will eliminate many future problems,” Crahen said.
For the life safety systems mandated nationwide in stores, schools, offices, hotels, hospitals, and public spaces of all types - beyond lightning, the power surges from brown outs, black outs, grid switching, and large equipment draw can also wreak havoc, potentially bringing increased scrutiny and fines from fire inspectors.
“Unmonitored systems could be unoperational for months - until discovered by a fire marshal or alarm contractor,” said Craig Torrey, a fire inspector for the city of Anchorage, Alaska, who earlier in his career supported the proactive use of aftermarket surge suppression in Collier County, Florida. “Since a ‘downed property’ without a life safety system would be at increased fire risk, the owner might be directed to fix the system in as little as 24-48 hours, and may have to establish a continuous 24-hour firewatch by qualified personnel such as off-duty firemen in the interim, or face shut-down.”
“For a medium-sized store, that might cost up to $5,000 for a few days,” continues Torrey. “For a large hotel, the bill could reach into the tens of thousands of dollars - on top of system repair or replacement costs. That’s an extraordinary penalty to pay, when life safety systems can be properly protected from the start with adequate surge protection.”
Electrical deregulation, as exemplified by the rotating outage numbers recently assigned to California Edison customers, may also hasten power fluctuations as supply and transmission issues are worked out in the “marketplace.”
“How many times have you seen your VCR flashing 12:00 or your microwave read ‘PF’ for power failure?” said David Burke, a senior executive at DITEK, a leading manufacturer of commercial, industrial, and residential surge protection. “That means you had a voltage spike large enough to re-set your system. If the lights dim then return when the building next door tests their back-up generator, that’s a power spike as well. Air conditioning units and other large equipment cause power fluctuations of larger magnitude. For example, at an Orlando, Florida convention I attended, there was a 20V overcurrent each time the air conditioner chillers kicked in. A demo unit with an audible alert and built-in surge counter registered the overvoltage each time the HVAC service cycled through. Even when systems continue to work properly, over time transients will take a toll on sensitive electronics, reducing system life by as much as 30%.”
How Aftermarket Surge Protection Can Help
So why add aftermarket surge protection when most panels have the devices built into the control board? According to the May 2000 NBFAA brief, “By installing a surge protection device at the electrical outlet where the transformer is plugged in, you allow the damaging transient to be bypassed to ground BEFORE it gets to the control panel, thereby greatly reducing the potential for false alarms and/or damage to the control board. The same is true when you install surge protection on the phone line prior to it entering the panel.”
“Add surge protection on both the AC (electric power line) and the phone line,” continues the brief. “Many panels are zapped when transient voltage jumps the phone company’s lightning protector and sends 100’s or 1000’s of volts where only 48V normally reside.”
DITEK’s Burke explains, “People put a surge protector on the AC power and think they’re protected. But only 30 to 40 percent of all damaging transients actually come in on the AC circuit. Most enter through the phone or data/communication circuits that run from building to building. Any wiring to the panel is a possible entry point for transients that should have adequate surge protection.”
What is adequate surge protection? To start, surge suppressers should be UL-listed and installed a minimum of three feet from the control panel for a margin of safety. This usually requires aftermarket surge suppression. While most built-in protection does meet minimum UL requirements, this usually takes the form of a small fuse or metal oxide varistor. The downside of built-in protection is that it allows damaging transients inside sensitive panels, which can disrupt function, including ground faults, trouble alerts, and communication failures. And if the voltage dissipation isn’t adequate, there’s no recourse other than replacing the damaged equipment, which can cost tens of thousands of dollars in severe instances.
Use “surge protectors that self-restore after dissipating the surge harmlessly to ground,” as the NBFFA brief recommends. “Each time they do so it is a false alarm prevented,” continues the brief. Self-restoring surge protectors wait for a predetermined voltage to be achieved, clamp the overvoltage shunting it to ground, then automatically reset themselves to passive mode until it happens again. They can stop hundreds of surges unlike single-use devices, which offer no protection after a surge until replaced. When a catastrophic surge is detected, self-restoring devices “self-sacrifice” as do single-use devices, to protect sensitive equipment from damage. The most reputable companies offer a lifetime-warrantee that replaces any device that self-sacrifices.
Buy the proper surge protector for your application, since fire panels have different circuits that follow specific protocols. The best bet is to look for a manufacturer with a wide selection of surge suppressers with the specific model that suits your needs. It’s unwise to use a generic model designed for use on scores of applications, since it will have generic properties that likely won’t work well for your specific application.
“Put the wrong surge protector on a circuit and you can create more headaches than you fix,” says DITEK’s Burke. “For example, if you place a high-voltage surge protector on a low-voltage circuit, it might not clamp until 30-volts or higher, at which point the circuitry will already be destroyed. Alternately, if you put a low-voltage surge protector on a high-voltage device such as a horn/strobe circuit, the normal operating voltage of the horn/strobe may be seen as hostile current by the protection device. That’s a recipe for false alarms or ground faults.”
Choose surge suppressers that meet the latest codes, as fire codes at the national, state, and local levels may vary and are subject to change. Buying from a manufacturer that builds on demand is one way to ensure getting suppressers that meet the latest requirements. Since some manufacturers mass produce and warehouse product that may fail to meet the latest codes, buying from them may be unwise if your own codes are in flux. At times, to meet specialized codes or mandates especially at the local level, it may be necessary to work with a manufacturer that builds customized surge protection features. Completely customized suppressers are possible from design concept to finished product within a couple month timeframe from select manufacturers.
Keep up with technological advances that can make your life easier. “For convenience and continuous protection after a catastrophic surge, replacement smart module technology is worth looking into,” adds Burke. “This technology was originally developed for school and government use, where multiple buildings or campus-style system designs are common. It quickly identifies any sacrificed protectors with a red failure diagnostic light, which eliminates time-consuming, on-site troubleshooting. Its two-piece modular design enables quick replacement with no tools or test equipment: just pull out the bad module, snap the new one into the base assembly, hit acknowledge-reset, and the system is back in operation and fully protected.”
To protect data and video production devices from surges as well as “ghosting,” a new technology is also worth searching out, as it protects the circuit from surge and isolates suppresser components from the circuitry of the system protected. The technology combines silicon avalanche diodes (SAD) with a diode bridge integrated into one component, providing protection and isolation in one package. With fewer components to fail and less circuitry on the PC board, this improves reliability in a more compact suppression design than typically available.
Savvy installers, administrators, and OEM engineers know that while lightning is still a rare occurrence in some parts of the country, the trend toward ever more sophisticated, low-voltage life safety systems continues: and with it power surges from brown outs, black outs, grid switching, and large equipment draw that can compromise their systems. Because life safety systems must not fail, they’re increasingly turning to specialized aftermarket surge suppression devices to minimize component damage and false alarms caused by transient voltages. Proactive fire marshals and organizations such as the NBFAA are not only leading the charge, but guiding it as well, so we’ll all be a little safer - in whatever public place we find ourselves.