1
13Owen
Guest
I work in the security industry and am servicing older alarm systems with
multiple alarm detector per alarm input. Nowadays we dont have a problem
with too many alarm detectors for the number of alarm inputs. We buy a 16
input panel and just keep adding 8 input expander cards until there are
enough inputs.
In the past most alarm panels had either 4 or 8 inputs and here in-lies my
problem. I have dozens of sites to service that have in excess of 100
detectors and only two or three alarm panels, usually 30 to 40 detectors per
panel. With the eighth input used for a key switch that leaves 7 inputs
divided by say 35 detectors leaving 5 detectors wired in series per input.
That is fine until there is an intermittent false alarm problem. WHICH !!!!
of the five or so detectors is the problem or has an envrionmental problem.
I have done things like short circuit one at a time until the problem goes
away which didn't work because the problem being intermittent when I got to
the last one it didn't play up. "Murphy's Law" Murphy is a SOD. So I hooked
them all together in series again and guess what? The thing played up again.
Also it may be over 100km to the site and the cost is too prohibitive to go
there half a dozen times also the level of security is tainted by having
multiple dectectors taken out over a long period of time.
It has been suggested to replace the detectors with ones that are less
likely to false alarm which gets expensive to through away four good
detectors just to find a faulty detector and you find that the problem was
the environment anyway and not the detectors. Or to rewire them so that they
are not is series but the sites are very large and there is not the inputs
spare anyway.
Or increase the size of the panel which would involve a total rewire and
upgrade and overhaul of the whole system costing in excess of $60,000.00 or
$100,000.00 to fix a $100.00 detector or even an envorinment problem for $0?
I tried with some success with universal wireless TX's and an 8 channel RX.
I connected a TX across each of the alarm detector output relays and wired
the RX output relays in series with the other alarm panel inputs. This
worked by having the false alarms appear on one of the other alarm sectors
and by going to the corresponding TX I was able to find the problem. This
involved only two visits to the site and the level of security was not
compromised. I was also able to monitor the wiring by joining the alarm
wires at each detector an monitoring that as well. Sounded good until the RX
would lock up or I had a problem with the distance from the TX back to the
RX.
There must be an electronic solution.
There is one pair of cables with 5 or 6 contacts in series.
Thats 5 or 6 actions for the 1 reaction.
How do you turn those 5 or 6 actions into 5 or 6 reactions.
Without major works.
Yes you would have to go the each detector and do something and that is OK.
Having a small device at each detector is OK. Having something small like a
resistor of a few small component that would fit inside the detector would
be better. There is 12 Volts available at the alarm panel and room to fit a
circuit board. This needs to work only when the alarm system is turned on.
There are lots of people in the building during the day. The results may be
record on or off site and viewed later. There is access to the key switch
input for switching purposes.
This has had me puzzled for years and I would love to beat it.
Owen
(remove "no-spam word" from e-mail to contact me)
multiple alarm detector per alarm input. Nowadays we dont have a problem
with too many alarm detectors for the number of alarm inputs. We buy a 16
input panel and just keep adding 8 input expander cards until there are
enough inputs.
In the past most alarm panels had either 4 or 8 inputs and here in-lies my
problem. I have dozens of sites to service that have in excess of 100
detectors and only two or three alarm panels, usually 30 to 40 detectors per
panel. With the eighth input used for a key switch that leaves 7 inputs
divided by say 35 detectors leaving 5 detectors wired in series per input.
That is fine until there is an intermittent false alarm problem. WHICH !!!!
of the five or so detectors is the problem or has an envrionmental problem.
I have done things like short circuit one at a time until the problem goes
away which didn't work because the problem being intermittent when I got to
the last one it didn't play up. "Murphy's Law" Murphy is a SOD. So I hooked
them all together in series again and guess what? The thing played up again.
Also it may be over 100km to the site and the cost is too prohibitive to go
there half a dozen times also the level of security is tainted by having
multiple dectectors taken out over a long period of time.
It has been suggested to replace the detectors with ones that are less
likely to false alarm which gets expensive to through away four good
detectors just to find a faulty detector and you find that the problem was
the environment anyway and not the detectors. Or to rewire them so that they
are not is series but the sites are very large and there is not the inputs
spare anyway.
Or increase the size of the panel which would involve a total rewire and
upgrade and overhaul of the whole system costing in excess of $60,000.00 or
$100,000.00 to fix a $100.00 detector or even an envorinment problem for $0?
I tried with some success with universal wireless TX's and an 8 channel RX.
I connected a TX across each of the alarm detector output relays and wired
the RX output relays in series with the other alarm panel inputs. This
worked by having the false alarms appear on one of the other alarm sectors
and by going to the corresponding TX I was able to find the problem. This
involved only two visits to the site and the level of security was not
compromised. I was also able to monitor the wiring by joining the alarm
wires at each detector an monitoring that as well. Sounded good until the RX
would lock up or I had a problem with the distance from the TX back to the
RX.
There must be an electronic solution.
There is one pair of cables with 5 or 6 contacts in series.
Thats 5 or 6 actions for the 1 reaction.
How do you turn those 5 or 6 actions into 5 or 6 reactions.
Without major works.
Yes you would have to go the each detector and do something and that is OK.
Having a small device at each detector is OK. Having something small like a
resistor of a few small component that would fit inside the detector would
be better. There is 12 Volts available at the alarm panel and room to fit a
circuit board. This needs to work only when the alarm system is turned on.
There are lots of people in the building during the day. The results may be
record on or off site and viewed later. There is access to the key switch
input for switching purposes.
This has had me puzzled for years and I would love to beat it.
Owen
(remove "no-spam word" from e-mail to contact me)
BTDT.