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AT&T 8520 Smoke Detectors |
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Disposal (Don't!) |
 tm Copyright © 1994, 1995, 2000 Luis Arellano, III. All
rights reserved.
|
|
|
Click a topic or page down |
AT&T 8520 Smoke Detectors |
|
Disposal (Don't!) |
tm Copyright © 1994, 1995, 2000 Luis Arellano, III. All
rights reserved.
|
|
IMPORTANT NOTICE
CONCERNING
DISPOSAL
OF
AT&T SMOKE DETECTORS
AT&T SMOKE DETECTORS ARE REPAIRABLE UNITS.
If they malfunction, do not
toss them out, they are expensive.
Call
Reliance Alarm Company for assistance to silence the
alarm until service can be arranged.
In short, we will
instruct you to remove the batteries
from the offending detector, and put it inside a sealed plastic bag, so we can
later tell if bugs did it.
We have had numerous cases where
uninformed homeowners or well meaning members of the fire department have
discarded AT&T smoke
detectors because of false alarms.
Usually,
these alarms are attributable to one of three problems: Dust
accumulation, bugs or electronic failure.
All of these can be
fixed.
The
detectors can not be replaced by department store
detectors because of the radio transmitter built inside the AT&T
unit, which links the detector to the Central Control system.
If
you discard a detector, we will have to charge you
for a replacement, even
if you have the optional Repair Contract.
WE
HAVE LABELS AVAILABLE
to
warn persons not to discard the detector.
These were mailed to all our subscribers
owning this system. Please take the detector
down and stick the label to the back of the unit.
If you prefer, put the labels
and the copy of this letter that came with them at the Central Control Unit, and
ask us to do it for you the next time we are there.
IMPORTANT
NOTICE
CONCERNING
CLEANING
OF
AT&T SMOKE DETECTORS
AT&T SMOKE DETECTORS MUST BE CLEANED PERIODICALLY.
If they are never cleaned,
they Will cause false fire alarms!
That
is the essential message. You
don't need to read any further
unless you happen to be interested.
General Information.
There
are two major types of smoke
detectors. One
type, the "IONIZATION" type,
uses a radioactive element which reacts
directly with products of
combustion. This is the type of
detection commonly found in
cheap department store detectors.
This type of detector is very sensitive to common household
phenomena such as frying of food, burnt toast and cleaning agents.
The
"PHOTOELECTRONIC"
type uses a light beam shining across the
inside of a dark chamber. If smoke
particles enter the chamber, they
scatter the light beam.
In a tunnel off the side of the main chamber,
the scattered light hits a photo
sensor. Most central
station alarms, including the AT&T 8000 system, use this type of
detector, because it measures the actual density of
any smoke present,
and is more resistant to
the nuisance
alarms described above. However,
it is prone to certain other types of
unwanted activation, including insects and dust accumulation.
INSECTS
include spiders and small
cocoon-weaving worms. We
recommend that
you frequently examine the spaces around each
detector and brush away anything foreign that you may see.
When we check
a system, we often will insert a mothball
inside the detector case. However,
this is a short-term measure
because mothballs evaporate within a couple of months.
Insecticides may kill away
existing bugs, but are not a long term solution because EPA regulations require
that they be biodegradable.
DUST ACCUMULATION is a long term
phenomenon with which you should be concerned.
It is the primary reason for this memo.
We note a regular incidence
of false alarms that
result from
customer unawareness of this condition.
The
inside walls of the dark detector chamber have a flat
black finish. Very
fine particles accumulate on the walls. They may not even
be visible under direct scrutiny, but
they gradually change the
coloring of the chamber to gray, causing more and more light
to be scattered.
This makes the unit more
sensitive. Finally, when the
threshold of detection is exceeded, the detector
goes into alarm every time a
battery is inserted. If
you open the
chamber and rub your finger across the inside wall,
often you can see a noticeable contrast.
The
rate of dust accumulation depends on environmental
factors. These include dust
from construction and hobby activity, the type of
heating system,
the use of fireplaces and
other heaters, general
commotion level, cooking and cleaning habits, etc.
Some environments do
not seem to cause
significant dust
buildup, others need frequent attention.
Our Recommendations.
Dust
accumulation is a concern with any brand
of photoelectronic
detector. However, we
observe that the AT&T detector is
most prone
to dust problems if the
detector is mounted on a ceiling.
(We have discussed this problem with the
manufacturer, however, no
design update appears to be coming.)
We therefore advocate moving
these detectors onto a wall when it is
practical to do so, and when
dust accumulation is noticeable.
This can also eliminate
the need for tall ladders. (There
is no particular loss of
coverage. The edge of the
detector must be at least six
inches away from any corner.)
It is important to cover up the
units or take them out of the
room if dusty work or spray painting is to be done.
We
also recommend having your system checked by a technician on a regular basis, typically annual.
While we are there, we can demonstrate
how to clean the detectors, if you would like to
do it yourself the next time.
HOW YOU CAN CLEAN THE DETECTORS YOURSELF.
Click Here to See Warnings Before Proceeding!
First
call the central station and advise the operator
you are working on your system.
Press
the black release tab near the base of the detector.
The unit will swivel out. Lift
it off the hook at the opposite side
of the base.
Lay the detector
face down on a table and remove the two
batteries by gently prying them out with a screwdriver.
The unit will make one
or two chirps and then it will be quiet.
Look for the
yellow warning label. (Go ahead
and read it.) Just above
the label is a small rectangular hole.
Down in the
hole you will see the edge of a flat white tab.
Use a screwdriver to
push that tab toward the center
of the unit. This will
release the lid, and the black base can be swung up toward you.
Turn the unit over and lay it on its base with the white cover tipped
away from you.
Situated
on an angle in the upper
right corner is a black
box which stands on four
stilts. Two of these stilts,
the leftmost and the rightmost,
have tabs that go down through the
circuit board. They hook outward to hold the box to the circuit
board. With your thumb
and forefinger, squeeze these two corners
toward each other, and
wiggle the box. First the left,
then the right tab,
can be
unhooked and pulled out of the
circuit board.
(Sometimes there is a tiny dab of silicone along the side of
the black box. Go ahead
and gently pull it free, or cut it.)
You
will end up holding the
black smoke chamber in your hand.
Turn it over and look
inside it with a flashlight for spiders,
webs, cocoons
or dust. They may be
extremely fine, look very carefully! (The
inside of the chamber is supposed to be absolutely flat black. If it
has a gray cast, there could be very fine dust
You can gently lift out the wire screen, but be careful to put it back in the same direction. Use a small, soft paintbrush to thoroughly dust out the chamber. Do this even if it doesn't look dusty. Then blow it out. (Sometimes the dust is so fine it can't be brushed out. You can use some liquid hand soap or dish detergent and lukewarm water on your brush to wash the chamber. I have never cleaned one in a dishwasher, and I don't recommend it. Don't drop the smoke chamber into the drain. Make sure you don't leave any soap film behind. Air drying is best, because paper towels, rags, etc. can leave lint. It will take a while to dry.)
Brush any dust or
lint off the wire screen. If it is
greasy dirt, you may need to use some detergent on a small brush.
Observe the black
detector assembly which was beneath the black box on the circuit board. Spiders
like to curl up in the space in front of the light source.
If you find any, get them out! If
they get away and crawl down into the works, that is not good.
You will need
to get them out or kill
them before placing the unit in service.
One way is to put the whole thing in a plastic bag with a few
mothballs and leave it sealed up for a few days.
Brush away any
other dust or webs you may observe in the
innards of the detector.
If there is noticeable dust or black
residue around
the inside of the white cover, the detector will
require more frequent
cleaning than others. If the
inside of the cover looks
sooty, have
your furnace flue checked, you may
have a carbon monoxide
problem.
DO NOT IMMERSE THE ELECTRONIC COMPONENTS!
Use
a warm,
soapy cloth to clean the cover, then wipe it dry.
To reassemble:
Be sure to reinsert the wire screen in the black box. (For most, a notch in the side of the screen matches a tab in the chamber.)
Note that the two stilts with hooks are different sizes. The larger one goes to the right. Snap the box back in place.
Look around for leftover parts. If none, snap the cover shut.
Reinstall the batteries. Make sure you install only Duracell™ alkaline batteries. Many alternate brands do not fit the space properly. Also, the detectors are only UL Listed when used with the specified batteries. Make sure they snap down flat in their compartments. You should feel a little "thump" as they seat. If they are not fully seated, you will have trouble putting the unit back on its bracket.
Put it back
on its mounting bracket.
There is a hook on the bracket. It goes into the edge of the detector
base. Then the rest of the unit will snap into place. Don't
force it, just wiggle it around a little and it will easily go into place.
TESTING:
WARNING! If you test the smoke detector without setting the "Test/Demo" or "CC Test" mode, a fire alarm signal will be sent!
Even
if you set the Test/Demo or CC
Test mode,
we recommend that you be sure the Central Station is
disregarding alarms before you proceed. (
It will be loud. Warn others who are on the premises. Protect your ears as you hold the test button.
Depress the round white test button on the face of the detector. You will need to hold it for 15 to 30 seconds before anything happens. Then the detector will squeal and a moment later the Central Control unit and any associated siren speakers will sound.
To stop it all, go to the Central Control Unit.
When you get there, the ID number of that smoke detector should be in the display. Compare that number against the location described on the Transmitter ID card, to be sure the detectors have not been switched around with each other.
Touch the "CANCEL" button.
Repeat
the test for each detector you have.
Clear out the
system's internal event log by alternately pressing the "MESSAGES"
and "CLEAR DISPLAY" buttons,
until all you can get is "-0"