In April’s “Fire Side Chat,” I discussed the implementation of a manufacturer-specific ancillary relay to interface tandem line, 120VAC smoke alarms with a combination residential burglar/fire alarm system. In that story, I said in order to comply with code, you have to have a listed relay.

This suggested application prompted a number of responses from the field and, consequently, a good deal of research on my part. Let’s begin with some of the responses as well as the reason why this application is in question.

Field Veterans Make Their Cases
Nick Markowitz, owner of Markowitz Electric Protection of Verona, Pa., wrote, “NFPA forbids tying 120VAC smoke alarms with 9V backup batteries into fire panels because the UL-listed relay sold to use with them de-energizes with a power failure, causing a false alarm.”

Markowitz is partially correct. Although NFPA 72, National Fire Alarm Code, does not specifically endorse the use of a relay for interconnection, there is nothing in the code itself that forbids it. But, there is a short paragraph in NFPA 72 that would suggest that it is not a code-compliant method when the intent is to monitor smoke alarms using a supervising station or central station.

As to his satement of false trips when power is lost, evidently not all makes/ models will react in the same way when a structure’s power is lost. The responsible thing to do is bench test the smoke alarms and ancillary relay you intend to use if you decide to do it.

Will Fleenor with Fleenor Security Systems of Johnson City, Tenn., also contributed correspondence.

He wrote, “I called the manufacturer [of the smoke alarms we use], which is BRK, and asked about the listed uses of the 120VAC smoke loop relay. [According to them] it isn’t UL listed for the purpose of connecting smoke alarms to a fire-alarm system. They claim that the relay was not intended for this use and would never be listed for connection to a fire alarm system.”

A Look at Ancillary Relay Listings
Fleenor hit the nail on the head. It is the lack of a proper third-party listing that calls this application into question.

In Section 1-5.1.2 of the 1999 NFPA 72 Edition, it says, “Equipment constructed and installed in conformity with this code shall be listed for the purpose for which it is used.” Section 4.3.1 of the National Fire Alarm Code Handbook 2002 continues, “Fire alarm system components shall be installed in accordance with the manufacturer’s installation instructions.”

The first portion of this NFPA 72 provision calls into question the “intent” portion of our suggested application, as it relates to the third-party listing. Now, one smoke alarm manufacturer has confirmed that the listing carried by these relays do not include interconnection with an alarm control panel.

The primary problem associated with listing an ancillary relay for interconnection with an alarm panel involves the lack of proper relay supervision. Although the circuit between a panel’s initiating circuit input and the relay’s output contacts can be supervised using an end-of-line (EOL) resistor, the relay coil and associated circuitry linking the smoke alarm tandem line to the relay cannot.

Does all of this mean you will never be allowed to use an ancillary relay to connect your client’s tandem-line, single-station smoke alarms to a combination burglar/fire alarm panel for supervising or monitoring? I promise to answer that question in a moment.

Homeowner Perception Cited
Code compliance is only part of the issue. A source close to NFPA points out the problem associated with monitoring this ancillary relay using a panel relates to the perception of protection by homeowners.

If the fire department fails to show up when a residential fire occurs because house power was lost and the ancillary relay failed to operate, will the homeowners understand? Or, if the coil in our ancillary relay was previously damaged by lightning six months prior during the summer months, will the homeowner be sympathetic to the fire technician’s position?

In most cases, both the homeowner and insurance company will want to know why the alarm company failed to fix the burned-out relay. After all, lives are at stake and alarm systems are supposed to be supervised. But providing more than what code calls for is a gray area that is not specifically addressed.

The problem is this coil cannot be monitored, and neither can the connection between it and the 120VAC smoke alarms. There is no way to know whether such a relay will work. With present fire detection technology as it is, there may never be a way to properly supervise it.

But even when used as listed — which is fire door closure, ringing bells and triggered lights — there is no way to assure proper supervision of this relay. What can be more serious than failing to release fire doors to prevent the spread of smoke?

All of this, even when using this ancillary relay as listed, calls into question an installer’s liability. In this letter-of-the law society, the insurance company may actively look for someone to blame so it can recoup some of its losses.

Use of Relay Is Really AHJ’s Call
Earlier, I promised I would share my interpretation of the code with regard to using an ancillary relay with tandem-line smoke alarms interconnected to a combination burglar/fire alarm panel for the purpose of monitoring. Now that we’ve discussed all the reasons why you might not want to do this, my advice is, it’s up to your local AHJ!

In single- and multiple-family dwellings, evacuation is the primary mandate of the fire-warning equipment that fire technicians install. Providing supervising station monitoring is certainly allowed and encouraged in Chapter 11 of NFPA 72, 2002 Edition, but it is not required.

According to Section A.11.3.2, NFPA 72, 2002, “This code establishes minimum standards for the use of fire-warning equipment. The use of additional alarms or detectors over and above the minimum standard is encouraged. The use of additional devices can result in a combination of equipment. Though a combination is allowed, one type of equipment must independently meet the requirements of the code.”

The term fire warning equipment, under Section 3.3.73 of NFPA 72, 2002, specifically pertains to devices related to single- and multiple-station alarms, also referred to as household fire alarm systems.

Also, in Section 11.7.6.7, it says, “Installations that include the connection of single- or multiple-station alarms with other input or output devices, such as but not limited to relay modules, remote signaling devices, phone dialers, security panels, heat detectors and manual pull stations, shall be permitted, providing that an open or short circuit of the wiring leading to these input or output devices does not prevent normal operation of the single- or multiple-station alarms.”

Further, to meet the requirements of NFPA 72, Section 11.3.1 of NFPA 72, 2002 Edition, says, “All devices, combinations of devices, and equipment to be installed in conformity with this chapter shall be approved or listed for the purposes for which they are intended.”

What this essentially means is that those devices covered by this section must either be listed by a third party or approved by the AHJ. Thus, although UL may not list this relay for use with combination burglar/fire alarm panels, in conjunction with tandem-line, single-station smoke alarms, the AHJ can approve these devices for this application, and believe me they do. Keep in mind that, according to code, it is not UL’s position to approve equipment but rather the AHJ’s.

In conclusion, when smoke alarms on a job meet all the necessary code requirements and the AHJ will approve the system as a whole, adding the same manufacturer’s ancillary relay may be acceptable. However, ask the local AHJ before you do it.

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