A Guide To Installing Smoke and Fire Alarms
According to a report published by the United States Fire Administration, America has one of the highest per capita fire death rates of all the industrialized nations. every year 3,000 Americans lose their lives to fires. every year, 20,000 more people, are seriously injured by fires. Fire kills approximately 3,000 and injures approximately 20,000 people each year. the majority of the deaths and serious injuries happen in home without working fire alarm systems. every year approximately 100 firefighters die trying to combat those fires that cause more than $11 billion in property damages.
On May 3, 2010, 47 of the fifty states passed a new law requiring all new home to have hardwired smoke detector systems installed. the primary power for these systems must come from the buildings electrical system with a battery back-up in case of a power outage. Smoke detectors whose primary power source is a battery are still recognized for use in existing dwelling but cannot be installed during new construction. it would behoove the prudent homeowner to install a hardwired system in his existing dwelling.
Why the requirements for a series, hardwired system
The stand-alone, battery powered detectors are effective as long as three conditions are all met simultaneously. the fire, the smoke detector and you must all be in the same location. if I was protecting my home with stand-alone detectors and there was a fire starting in the furnace room at 3 am in the morning, it might go unnoticed until too late. why? it might go unnoticed because all our bedrooms are on the second floor of our 2 and ½ story farmhouse. it might go unnoticed because the only detector that would have gone off is the detector in the furnace room. With the series wired system, every detector would sound the alarm no matter which one detected the fire. Isn’t that protection worth the time and effort it would take to install a hardwired system in you home? Isn’t that the protection that you want for your family, pets and property?
Hardwired smoke detectors must be on a dedicated circuit breaker.
Hardwired fire alarm system, like emergency light systems, must be on dedicated branch circuits, circuits with no other loads connected to them. you cannot legally connect a fire alarm system to a general purpose receptacle circuit, a lighting branch circuits or to any other circuit supplying one or more loads. the only loads permitted on a hardwired smoke alarm system are the smoke detectors and any other equipment associated with the detectors i.e. alarm sirens. because of this code requirement, the hardest part of installing a hardwired system will be getting the cable from the main panel to the various smoke detector locations.
Where should you install a detector?
Every state has its own requirements as where detectors must be installed. Check out The United States Fire Administration State-by-State Residential Smoke Alarm Requirements guide for details on your state’s requirements. This guide presents the minimum requirements by law, personally I believe you should have at least one detector in every room, hallway and storage area of your home.
What basic tools will you need to install your system?
Preparations
Prepare a sketch of your proposed installation and take it to your locality’s building permits department for a wiring permit. the drawing doesn’t have to look professional, but it must show where you are installing the detectors, with dimensions shown on the drawing. you don’t have to show the exact route the wiring will take between detectors and the main panel, but the drawing must show how they will be interconnected must be on the drawing. a single line drawn between the service panel location and the first detector with another single line extending between detector locations will suffice. Use 2 and ½ diagonal lines across the line representing the 14/2 w/Gr cable and 3 and ½ diagonal lines across the lines representing the 14/3 w/Gr cables. do not start this project until you have the wiring permit and have posted it as required by law.
Locate and make the cutouts for the outlet boxes.
Take a tour of your house and mark the approximate position where each smoke detector will be placed. Use the electronic stud finder to make sure that the detector mounting locations on the ceilings aren’t located over a floor/ceiling joist. Make sure that the cutout will be at least two inches from the nearest joist. the boxes mounting wings need to swing open and draw up against the ceiling finish to secure the box in place.
Adjust the drywall circle cutting attachment to cut the openings for the 4” octagon outlet boxes. Once you have cut all the openings for the boxes, you are ready to start pulling the wire through the wall, floors and ceiling. if you are lucky, your home will have an unfinished attic and basement which will make pulling the cable much easier. Pulling wire through finished wall can be a real challenge, no two jobs are exactly alike, but this tutorial has some excellent tips that will help you.
How to run wire in an unfinished attic or basement.
When running cable in an unfinished basement, basement crawls space, attic or attic crawlspace, you can run the cable along the sides of the joist or through holes drilled through the joists. when drilling holes through the joists, the National Electrical Code (NEC) and the local codes require that the near edge of the hole must be at least 1 and ¼ inches back from the nearest edge of the joist. if this spacing cannot be maintained, a “nailing plate” must be nailed to the joist over the cable location to protect it. when running cable along the side of the joist, it must be set-back 1 and ¼ inches from the nearest edge. when running cable along the side of a joist, it must be supported at 4 and ½ foot intervals with cable stapes. it must be supported within 12 inches of every box.
Connecting the smoke detectors
Insert the ends of the cables into the outlet boxes far enough for them to extend 6 inches from the front of the boxes. Push the boxes into the ceiling openings and secure in place by turning the wing screws in a clockwise direction. With the boxes secured in place use the razor knife to remove the cables outer jacket. Use caution hers so as not to damage the insulation on the individual wires.
Mount the smoke detector mounting rings to the outlet boxes using #8-24 screws that came with the boxes.
Remove ½ inch of insulation from the ends of the insulated wires with the wire strippers.
Connect the detector interlock pigtail connectors to the circuit wires. Splice the black circuit wires to the black pigtail lead. Connect the white circuit wires to the white pigtail wires. the black and white circuit wires are the wires providing power to the detectors. Connect the yellow pigtail wire to the red circuit wire. the red circuit wire is the one that carries the alarm signal to all the detectors when any one of them is set off. Red, White and Yellow is pretty much the standard color code for hardwired detectors but check the wiring diagram that came with your detectors to be on the safe side. Splice the bare. Copper circuit ground wire to the copper ground wire on each detector.
Make the splices by holding the stripped ends side by side and twisting them tightly together in a clockwise direction using the Lineman’s pliers. Remember that every good electrical connection begins with a solid mechanical connection. Complete the splices by twisting on a wire nut and taping the connection. Tug on the finished splices to make sure that the wires are being held together.
Plug in the detector heads but do not mount them to the boxes until after your work has passed inspection.
Install the single-pole, 120-volt, 15-ampere circuit breaker in the service panel with the breaker in the off position, attach the black circuit wire to the circuit breaker. Attach the white wire to the neutral bar and the bare, copper ground wire to the panel’s ground bar.
Call for the required inspection. after your work has passed inspection, close up the circuit breaker panel and attach the detector heads to their mounting rings. Turn on the circuit breaker and test the system by holding a smoking test stick near the detectors.
