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false alarms on series circuits

1

13Owen

Jan 1, 1970
0
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.
 
S

Spider

Jan 1, 1970
0
Check out www.actmeters.co.uk

Regards

Ian
13Owen said:
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.
 
S

Spike

Jan 1, 1970
0
Sounds to me like you're looking for indication of which device tripped. I
gather the device is powered. If you don't want to replace the device with
one that does indicate IT was tripped (led), then a relay could be wired to
the device to indicate this... tell us more about the *device*
The Tx idea was pretty clever, expensive, but clever.
 
S

Spike

Jan 1, 1970
0
sorry, i just re-read your post.
you have a relay on the device. just add another relay to it that will
either latch thru it's own contacts or open (and stay open) from a 'latched'
condition..
 
R

RH.Campbell

Jan 1, 1970
0
I think there may be another (albeit expensive) solution. Put in a Paradox
Digiplex system with the motion devices that utilize serial numbers to
indicate to the panel which device went into alarm. However, this may not
indicate where the actual problem is, just which actual motion went into
alarm (since any number of devices on a loop can be defined as the same
number of separate zones....)

It's actually possible (but stupid and lazy) to put all exterior devices on
one series loop around the house with this panel (although I know some
companies locally that do it.....:((

RHC
 
G

G. Morgan

Jan 1, 1970
0


For what? Which one of these products fits the bill?




ACT2000 Digital MultiMeter
ACT3000 Autoranging Digiital Multimeter
ACT5000 Autoranging Digital Multimeter
Multimeter Test Leads & Carrycases
Checkmaster Calibration Testkit
Instrument Re-calibration Service
ACT620K Cable Tester
ACT-LanRoverPRO Test Set
ACT452 Telephone Test Set
New GOLD-IBT Intelligent Battery Tester
IBT-RTL (Replacement Test Lead) Kit
ACT226 Emergency Lighting Battery Tester
ACT672 Nicad Battery Tester
ACT512 SLA Battery Charger
ACT1050 Battery Saver
Alarm Installers Testkits
Checkmate Radio-Linked Testmeter
Son of Checkmate Sight & Sound Meter
ACT iD Testmeter
ACT K1 Low Current Clamp Meter
ACT Securitest Mains Multitester
ACT180 Zap Checker
ACT1502 Digital Sound Level Meter
ACT1330 Digital Light Level Meter
ACT Vidicheck CCTV Testkit
ACT TDR CCTV Cable Fault Locator
ACT1313 & 1414 Spike Suppressors
ACT2323 Mainspike Suppressor
ACT230MSF Mains Suppression Filter
ACT1166 Earth Line Choke
ACT CPS-3 Control Panel Suppression Kit
ACT TLC Telephone Line Conditioner
ACT1376 PIR Stabiliser
ACT2468 RFI Filter
ACT RFI Ferrite Cable Clamps
ACT4425 iD Line Filter
ACT120L Transistorised Relay
ACT 4201 (4 Zone) Opto-Isolator
ACT440 Global Tamper Splitter
ACT CCTV Hum/Lightning Protectors
ACT 0260 Timer Module
ACT Z420 Broadband DSL Alarm Filter
 
A

Allan Waghalter

Jan 1, 1970
0
I had the same reaction. I looked at each item and didn't find anything
that compares with a loopstick. For those who may not be familiar with this
tool, it is an audible ohm meter. When connected across a loop, it produces
a low tone for a low resistance and a high tone for a high resistance. It
transmits this tone over the loop wire itself as an RF signal. The receiver
can be used to locate the wire and can find opens, shorts and swingers.

If you have an open and you move the receiver along the loop, even in the
wall, when you pass over the open spot, there is a noticible glitch in the
tone. If you have instability of almost in sort, it can be heard in the
receiver. Tapping and stressing the connections to the devices will cause a
shift in sound if the connection is not good. If you open/close windows
along a loop, you can hear the switch in a given window function. It is
easy to isolate a section of the loop that is not working.

If you run into a really dificult area to locate or if you have multiple
problems on the same loop, you can connect the loopstick as instructed, run
a wire from the panel around the house to each switch on the loop and
determine exactly where your continuity stops. You will have to determine
which direction the loop goes from the panel.

Many of the tools at Labor Saving Devices are excellent, but the loop stick
is the one that I think is most essential.

Regards,
Allan Waghalter
 
G

G. Morgan

Jan 1, 1970
0
I had the same reaction. I looked at each item and didn't find anything
that compares with a loopstick. For those who may not be familiar with this
tool, it is an audible ohm meter. When connected across a loop, it produces
a low tone for a low resistance and a high tone for a high resistance. It
transmits this tone over the loop wire itself as an RF signal. The receiver
can be used to locate the wire and can find opens, shorts and swingers.


Cool, I've never used one of those. Maybe it's time to add one to the
toolkit. :)

Thanks.
 
P

Paul

Jan 1, 1970
0
This would only work if the devices were not powered through the day. Or
else it would trip straight away along with all other detectors. Also, if
the panel switches power to devices when it is armed, some detectors go
straight into alarm when first powered up.
 
A

Allan Waghalter

Jan 1, 1970
0
You put the device on the loop portion, not the powered portion. If you are
referring to a device such as a sentrol shock sensor, there is sufficient
voltage applied to the line from the loop stick to cause it to give you a
closed loop. Devices that go into alarm immediatly upon power up are
generally powered from the auxillary power supply, not the loop voltage.
Leave the power supply connected. You are looking for a swinger, are you
not? If your device receives power on arming, then leave it armed.

Good luck!
Allan
 
S

Spider

Jan 1, 1970
0
The item of interest could be the Checkmate tester, however, reading about
the Loopstick I'm trying to now find where I can buy one in the UK.

Ian
 
A

Allan Waghalter

Jan 1, 1970
0
Most all of the US alarm suppliers either stock tools from Labor Savings
Devices or can get them for you. Start by asking your local supplier. You
can always order direct from their web site.
www.lsdinc.com
 
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