Anthony J. Shalna, CET
John M. Stofa, CET
Executive Summary - The disastrous Station Night Club Fire in Warwick Rhode Island back in February of 2003 cost many lives and resulted in the updating and tightening of fire alarm codes not only in Rhode Island, but in many other cities, states and localities as well. To date, the Station Night Club Fire has resulted in $176 million in damages, as well as jail terms for the culpable person(s) found to be negligent.
Coupled with the tougher fire codes is the fact that the down economy has slowed new construction starts drastically since 2007. However, fire alarm system retrofits, that is, the replacing of obsolescent head-end systems with new head-end systems is becoming more popular, due to the advent of microprocessor-based systems and the lower cost of a retrofit as compared to a full system installation. Retrofits when planned carefully with a proper migration plan and installed according to all standards and codes make good business sense, but an alarming number of retrofits are falling short of meeting the fire alarm codes, creating a major liability and safety issue for all parties concerned.
Another affect of the current economic condition is the fact that fewer municipalities have funds available for the training of the Authority Having Jurisdiction (AHJ), Fire Prevention Departments, Fire Inspectors and Fire Marshalls who are responsible for signing-off on fire alarm installation projects and certifying that the installation complies with all applicable codes.
The purpose of this report is to point out some very obvious and not so obvious concerns in regard to fire alarm system retrofitting. It is to be considered as a “guide only”, and by no means is it to be considered a comprehensive set of instructions on how to perform a fire alarm system retrofit.
Equipment Cabinets – The idea that an existing fire alarm system cabinet can be retrofitted with new electronics equipment is one that can potentially save a significant amount of money for the end-user. The reuse of the cabinet will more than likely save days of labor hours because the electrician installing the new system does not need to uncouple the existing conduits, remove the existing wiring, reconnect the conduits and then reconnect the wiring into the new cabinet. However, if you intend to re-use existing fire alarm cabinets, these cabinets must be listed or approved by a Nationally Recognized Testing Laboratory (NRTL) for the specific control equipment being installed. The fact that the existing cabinet has an NRTL sticker affixed to it means nothing if the report or installation manual doesn’t specify that particular cabinet as being acceptable for use with the new electronic sub-assemblies involved.
The NRTL report is very specific about the cabinets and subassemblies required for a fire alarm control panel. This information is echoed in the system installation manual, which is also part of the NRTL report.
Modification of an existing cabinet by cutting, drilling or any other modifications will void any NRTL listing and automatically become a code violation unless the modification is approved or directed by the AHJ. An example of this would be addition of a component specified by local ordinance or regulation such as a special key cylinder for smoke control activation. Likewise, placing new subassemblies in an existing unapproved cabinet is also a violation. Some reasons are:
1.) A restriction or lack of air flow circulation could cause excess temperatures and possible component failure or performance issues.
2.) Routing of power limited and non-power limited wiring must be as specified in the new fire panel control panel manual.
3.) Existing wiring routing may contradict the power limited or non-power limited wiring required for the new system.
4.) Existing backboxes may not take into account RF and EMF issues corrected by the modern backbox thus leading to performance issues.
The new control panel will have a label affixed to the inside of the door that contains pertinent listing and wiring information, including the approved power limited and non-power limited wiring layout diagram(s). Modification of an existing door would mutilate the door label which is a violation. While a re-used door would contain an obsolete label; which should be a red flag to the competent and alert AHJ.
Excess high and low temperatures must also be considered. If the panel is relocated as part of the retrofit, recommended ambient temperatures may be exceeded. For example, locating a panel in a protected, but unheated outdoor enclosure may subject the panel to ambient temperatures outside the listed limits again causing unpredictable performance issues. Likewise, installing a panel in an area where the ambient temperatures are allowed to exceed the recommended operating temperature listed by the manufacturer could also result in performance issues.
Wiring – In the past, fire alarm codes were more relaxed in regard to the type of wire used in fire alarm systems. If the original installation pre-dates the advent of power-limited wiring requirements for fire alarms, the entire system will more than likely need to be re-wired. The comingling of power-limited and non-power limited wiring is against the National Electric Code and will cause major performance issues if allow to happen. This is one of the most frequently violated codes when dealing with sub-par installations performed by less than professional installers.
Furthermore, new addressable fire alarm systems transfer data packets from the field devices to the control panel and vise versa. Older wiring used with conventional type systems was not designed for the transmission of data but rather was used to determine a “make/break” condition and to measure the value of the End of Line Resistor. The expectation of being able to re-use this older wiring for a high performance microprocessor based fire alarm system is an unrealistic expectation of the wiring’s capabilities.
Finally, issues that the client is experiencing with their existing fire alarm system such as ground faults, shorts, wet/weather issues and raceway protection issues will not be corrected by simply replacing the fire alarm control panel. Misleading the client into thinking that those issues will magically go away is considered negligence. The problems with the field wiring must be found and fixed or they will carry over to the new system and leave the client dissatisfied and frustrated.
Compatibility Issues – This area is often misunderstood and can present a serious problem. Establishment of compatibility is required for 2-wire smoke sensors/detectors, electronic initiating devices, addressable monitor and control modules, notification appliances, and releasing solenoids. 4-wire smoke detectors are in the process of being included since some power supplies have been found to be outside the operating limits of these detectors.
Each panel manufacturer issues an NRTL listed/approved compatibility document that lists the various devices that are compatible with their corresponding fire alarm control panel. The panel Installation & Operating Manual may also contain this information. A smoke sensor manufacturer may also publish a compatibility document that is NRTL listed/approved.
If the device in question is not listed in any of these documents, then it is NOT COMPATIBLE and MUST NOT REMAIN IN SERVICE. If the installer intends to re-use existing 2-wire smoke detectors, the existing detectors must be included in the compatibility documentation.
Compatibility for 2-wire smoke detectors is not simply a matter of comparing current ratings of the detectors and initiating circuits. Unlike a contact closure device that places a short circuit across the initiating device circuit, the 2-wire detector, when it goes into alarm, presents an impedance across the circuit that is low enough to place the circuit into alarm, but not too low to prevent enough current to hold the detector in alarm, and keep the indicating LED lit. This depends on the area of intersection of response curves of both the detector and initiating circuit. All these calculations are also involved in determining the capacity of the initiating circuit as to the quantity of detectors that may be installed on it. The compatibility documents/manuals also state this information.
A major pitfall of retrofitting is mixing of different quantities of different models or brands of 2-wire detectors on the same circuit. Unless this combination is listed in an NRTL document, any mixing of models/brands would violate the listing. No one can predict what combination of models/brands/quantities would work properly. Only a qualified testing laboratory could verify and certify its operation.
Another area affecting compatibility is smoke level compensation. New generation microprocessor-based detectors have the ability to adjust their own sensitivity to compensate for dirt/dust build-up in the detector, smoke build-up, or gradual changes in the ambient environment. Re-installation of compensated detectors could result in unwanted alarms and subsequent frustration for the building owner. It is always a “best practice” to clean any existing smoke detector that is going to remain and subsequently be re-used with the new fire alarm control panel.
Often a smoke detector manufacturer will purchase a competitor’s fire alarm control panel on the open market in order to test their detectors with this panel, have the results verified by an NRTL, and publish the information in their own document. If you choose to use devices listed in a document published by a smoke sensor manufacturer rather than by the panel manufacturer, be aware of a possible problem. The panel manufacturer will assume no responsibility if the devices are not listed in his own document, since the detectors, “by others” were not furnished by him, or haven’t been tested by him. The reasoning here is the panel manufacturer has nothing to gain and everything to lose by approving a product not sold by him. Also, since the panels tested were purchased on the open market by the detector manufacturer, there is a possibility that the individual tested panel may have been damaged, improperly stored, or is from a production run that exhibited quality assurance problems, etc. This could eventually result in litigation that would only be settled in the courts.
And in conclusion ,with the exception of household, one and two family dwelling smoke detectors, requirements have not yet been established regarding the useful life (expiration date) of smoke sensors. However the National Fire Alarm and Signaling Code, NFPA 72, calls for reacceptance testing whenever fire alarm control equipment is replaced or reprogrammed. Electronic components age with time, filter screens may become clogged or partially clogged, materials become brittle with age, etc. Plan on and budget for the replacing of any smoke sensors or devices that fail the reacceptance test.
Manual Pull Stations (Boxes) – The Americans with Disabilities Act (ADA) specifies requirements for the manufacturing of pull stations and these requirements are now being enforced. The ADA
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Batteries - In most cases the fire alarm control panel installation manual will be specific regarding the model of batteries to be used. This manual is part of the NRTL report and therefore spells out the Listing.
Batteries designed for fire alarm signaling use will yield a steady current for a prolonged period of time. Appliance or automotive type batteries are designed to produce a high output for a short period of time and are not adequate or appropriate for fire alarm system use.
In addition, the instructions may specify replacement of the batteries after a certain period. An improperly selected battery might not last long enough to reach the replacement interval, and may fail during a power outage. Also, were the original batteries installed in an area where it could be exposed to excess temperatures? Were they properly maintained? Excessive heat or improper maintenance will shorten battery life considerably.
Notification Appliances – These devices are straightforward and far less complicated than sensor installations, but the newest panels depending on line voltage extremes, may present greater operating voltages which are outside the range of the existing notification appliances.
Since most NAC circuits are wired in a conventional fashion, the use of End of Line Resistors (EOLR) is still mandated on some circuits in order to maintain supervision of the circuit. As the name states, the resistor is to be placed at the end of the line. Any resistor mounted within the panel on any NAC circuit needs to be scrutinized. This EOLR mounted in the panel may elude even the best trained AHJ at times.
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Until recently, some jurisdictions have required that after an “alarm” and before the “system reset”, that the audible signals be silenced, but the strobes must continue to flash. It’s now being presented to them that to a hearing impaired person, a flashing strobe is an evacuation signal. Therefore, this regulation is in conflict with the codes that call for both audible and visual signals to be extinguished when the “signal silence” feature is activated following an evacuation.
Local Energy Master Boxes - Master Boxes are still in use in some parts of the country, notably New England and a number of military bases. All Master Boxes manufactured in the last 20 years or so are NRTL listed by the manufacturer. A number of repaired, refurbished or rehabilitated master boxes have been appearing in both new and retrofit installations. Occasionally a few of these master boxes still retain the original NRTL label. Re-use of this label on a “rebuilt” box could be interpreted as fraud, since repairing or rehabilitating a master box by someone other than the manufacturer voids any NRTL listing. Since the code states that all equipment must be listed for the purpose intended, installation of an unlisted master box would be a glaring violation of the code and open wide the door for liability in the event of a tragedy.
Furthermore, the installation of new electronic solid state and/or radio master box systems within older existing legacy master box shells has become a plague sweeping the industry in the last decade as cities and town no longer have the funding to maintain their 100 mil cable plants. This practice should also be considered fraud since the electronic and radio master box equipment typically is not listed by a NRTL to be installed within the existing master box enclosure. This fact is not made known to the customer when the new electronic system is purchased and installed and therefore the customer is unaware that they have been sold a system that does not meet any NRTL requirements. Again, subjecting everyone involved to legal implications should the non-compliant electronic or radio master box system fail to operate when needed.
Documentation – Older installations may have existed before the codes required the submittal of “As-Built” drawings. A retrofit installation requires creation of these drawings and proper storage of them. In addition, battery standby calculations are also now required when submitting fire alarm layouts to the AHJ for permitting.
Conclusion
In summary, the retrofitting of an older fire alarm system with a new modern fire alarm control panel is good business and can save the client or end-user thousands of dollars as compared to a new complete fire alarm installation. However, it must be understood that a properly installed retrofit system shall comply with all of the listing requirements, codes and precautions that accompany a new installation. Deviation and corner cutting to navigate around these rules will result in unnecessary damage to property and possible loss of life which is unacceptable to true Life Safety Experts and Industry Professionals.
