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Replacing An AC-Powered Smoke Detector
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In
This Article:
The power is turned off, the old smoke
detector is removed, and the wires are disconnected. New
wires are connected and the new smoke detector is installed. |
Related Articles:
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| Skill Level:
2 (Basic) |
Time Taken:
About 30 Minutes |
By
Bruce W. Maki,
Editor
Start:
There are a couple of reasons why you might
need to replace a smoke detector:
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Maybe the existing detector is too
sensitive and squawks whenever you're using the oven.
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Maybe you don't like the appearance or the sound of the old one.
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Perhaps you want
to upgrade to a dual function detector, which employs both
ionization and photoelectric sensing techniques.
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Manufacturers of
smoke detectors say to replace the unit after 10 years of use.
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Sometimes smoke detectors just malfunction. I know two families who
have had AC-powered interconnected smoke detectors suddenly start
screeching for no reason at all. In both cases this false alarm
happened in the middle of the night, and the homeowners had to
figure out which smoke detector was faulty and unplug it, not a
simple process in a big house when you've been woken from a deep
sleep.
When Inter-Connected Smoke
Detectors Sound A False Alarm:
If you are certain that the
smoke detectors are sounding a false alarm, and the
hush
feature fails to silence the beeping, then it's
necessary to remove and unplug smoke detectors
one-by-one until the beeping stops. (The last unit
unplugged would be the faulty one, of course.) The other
detectors could be re-installed, and the faulty unit
should be replaced as soon as possible.
Alternatively, you could just
turn off the circuit that powers the smoke detectors.
While some "safety experts" may bristle at the
suggestion of going even one night without working smoke
detectors, I'll point out that until smoke detectors
were introduced in the late 1970's, everyone did
that every night. But
here's a problem: In lots of houses I've seen, it's not
easy to locate the breaker that supplies power to the
smoke detectors. Consequently, I have used a
permanent marker to write "Smoke Detectors" or "S.D." on
the breaker panel cover, with an arrow pointing to
the breaker. That makes it easy for the homeowner to
find the offending circuit in the middle of the night,
in the event of a false alarm. In
my own house, I have a couple of plain-old
battery-powered smoke detectors in addition to the
interconnected AC-powered units. |
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| Most smoke
detectors simply twist off the base plate.
Usually the smoke detectors needs to be turned
counter-clockwise to remove it. BUT
FIRST... TURN OFF THE POWER TO THE SMOKE
DETECTOR CIRCUIT.
If there are no wires behind the smoke
detector when it's removed, it's a
battery-powered unit. |
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Editor's Note: I created this brief
article to explain the procedure for replacing an existing
AC-powered smoke detector. While these pictures are taken from my
article about installing new
smoke detectors with new wiring, they should help explain the
procedure.
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Then the electrical connector to the smoke
detector can be unplugged. Be careful... the
plug may have plastic "catches" that need to be
pushed, pulled or squeezed to release the
connector. |
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| Then the
mounting plate (base plate) can be removed. |
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The wires can be pulled out of the box. The
twist-on electrical connectors (wire nuts) would
be removed next. Those are the little yellow
caps in this photo.
(At this step you REALLY want the power to
be off.) |
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| Then the ends
of the wire can be untwisted with pliers and the
smoke detector pigtail can be removed. |
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I like to strip a little more wire from the ends
of the pigtails. With stranded wire, I prefer
about 3/4 inch of bare wire at the end, so it
can wrap around the solid wire. |
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| Then the new
pigtail can be connected to the house wiring,
and the wires can be tucked into the junction
box. Then the base plate can be installed, the
smoke detector plugged in, and secured to the
base. Turn the power back on and test the new
smoke detector. |
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Hush
Feature:
Most newer smoke detectors have a "hush"
button, which you push and hold until the beeping stops. On some
smoke detectors you simply press and hold the test button to hush
the device. When hushed, usually the device will ignore any detected
smoke for 15 minutes, and then it will be "on guard" again.
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More Info:
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- Phillips Screwdriver
- Wire Strippers
- Lineman's Pliers
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Materials Used:
- Smoke Detector, AC-Powered
- Twist-On
Electrical Connectors (Wire Nuts)
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