No, the wiring is not t-tapped or run in series with one conductor. The horns are shown using two-conductor cable, and the "red wire" is actually a pair of conductors. This is properly indicated by two hash marks on the lines depicting the wiring path.
Yes, the beds could be moved around and the pillows could wind up being farther from the strobe than the prescribed 16 feet. However, the fact that a room might be remodeled again someday after this installation is not a design consideration.
Building inspectors are there to determine that the installation went in according to the approved plans, and meet the rules of the adopted building code, as installed. Actually, any number of things can happen to make an installation non-compliant in the future. That's why ongoing inspections are required of you by NFPA 72 and regular inspections are conducted by your local fire prevention officers or fire department. Besides, like most hotels and motels, the headboards on the beds are permanently mounted to the wall.
No, the plastic raceway does not have to be specifically listed for use by fire alarm systems. Actually, the cable could have been legally run exposed, and merely fastened securely into the corners of the wall and ceiling using nails and clips. Placing the wiring inside plastic raceway for aesthetics does not violate any rules. Similarly, it could have been hidden in a hollow space behind wooden crown molding in each guest room, but the higher cost to add this molding was rejected by the owner.
Yes, it is true that routing the wiring inside the walls would have been best. Yet the wiring exiting the rear of the plastic raceway is not a violation; also splices and connections were all made at the appliance and no additional junction box was required.
No, the devices were not mounted eight inches too low, at 72 inches. The 80-inch minimum mounting height for wall mounted visible notification appliances does not apply to sleeping rooms. Instead, the rule for sleeping rooms requires that if a 110cd. strobe is used, it is to be installed at least two feet below the ceiling; otherwise, you must use a 177cd. strobe. Besides, when laying down in bed, this height difference is nullified.
Yes, a surface back box could have been used to mount the first horn/strobe, with the surface raceway mated to it and the wiring entering the side of the box, instead of how it is shown entering from inside the wall. This was not done because using a surface box would have been even more unsightly than exposed wiring and would have added to the expense without adding appreciable safety benefits. Actually, surface mounted appliances (including sprinkler heads) in guestrooms are sometimes compromised when they get used as hooks for coat hangers or even draped with clothes. (Look for the increasingly popular international "no coat hangers" symbol next to the sprinkler heads in many hotel guestrooms.)
Some people guessed at violations that could not possibly have been determined by the information provided and the illustration pictured here, which was included.
No, the notification appliances and boxes do not have to be listed together as an "assemble." Everyone should be satisfied as long as the associated electrical boxes/conduit are of the proper size, with conduit/raceway/ wiring installed per manufacturer's instructions, NFPA 72 and NFPA 70.
It is true that sometimes components are listed together as an assemble, when a combination of certain parts are required to make that device/installation comply with a code or standard. For example, usually a special back box is required for installations in damp or outdoor locations and the installation instructions would indicate this. However, this project's notification appliances are installed per the manufacturer's installation instructions which were reviewed and accepted as part of the original listing process of the appliance.
Yes, finally, the devices are not spaced far enough apart and, in fact, are installed almost back-to-back. The reason this installation violates the rules is that their close proximity to each other would allow a fire in one unit to more easily pass through to the next, spoiling the wall's fire rating. The NEC has a rule regarding this in Section 21 of Chapter 3, "Wiring Methods and Materials."
300.21 Spread of Fire or Products of Combustion states: "Electrical installations in hollow spaces, vertical shafts, and ventilation or air-handling ducts shall be made so that the possible spread of fire or products of combustion will not be substantially increased. Openings around electrical penetrations through fire-resistant-rated walls, partitions, floors, or ceilings shall be fire-stopped using approved methods to maintain the fire resistance rating.
"FPN: Directories of electrical construction materials published by qualified testing laboratories contain many listing installation restrictions necessary to maintain the fire-resistive rating of assemblies where penetrations or openings are made. Building codes also contain restrictions on membrane penetrations on opposite sides of a fire-resistance rated wall assembly. An example is the 600mm (24 in.) minimum horizontal separation that usually applies between boxes installed on opposite sides of the wall. Assistance in complying with 300.21 can be found in building codes, fire resistance directories, and product listings."
The Fine Print Notes (FPN) in this NEC section mentions compliance with the building codes. A check of the 2003 edition of The International Building Code gives you the requirements for protecting the rating of one-hour rated fire walls in 712.3.2. If you are using the 2000 edition of the IBC, it is in found in 711.3.2. The entries are identical and state, in part, "Outlet boxes on opposite sides of the wall shall be separated as follows: (1.1) By a horizontal distance of not less than 24 inches (610mm)."
This problem would have been a lot easier to notice if it had been new construction and the relationship of both boxes were able to be seen because the walls were not yet covered with drywall board. As it was, it took a sharp inspector only a couple of rooms to notice that the appliances were installed back-to-back and not a couple of feet apart as the approved plans indicated.
This installation no-no might also have come to light after the hotel reopened and the manager began to notice that these rooms seemed to have developed a new trend for complaints of noisy neighbors and too-loud TVs from the occupants of these adjacent guest rooms, since sound can also pass more easily through these openings, as well as heat and smoke.
Greg Kessinger, SET, CFPS, president of an alarm installing company since 1981, teaches NICET training classes to fire alarm system designers and installers and continuing education seminars for Ohio's fire alarm inspectors. You can reach Greg Kessinger at 888-910-2272; e-mail: email@example.com; or visit his website at www.FireAlarm.org.