TYPICAL alarm installations are benign and unlikely to
challenge carefully planned solutions but in external and harsh industrial
applications there are environmental variations that are able to trip over all
but the most capable detectors.
Complete Security, which started as a guard and response
company and expanded into installations in the mid-80s, faced just such a
challenge when installing alarm systems in 13 Cradle Coast Water sites around
Devonport in the north of Tasmania.
According to Complete Security’s senior tech Jamie Kaye,
some of Cradle Coast Water’s pump houses have characteristics no ordinary
sensor can handle.
“We have a policy of using the same gear in each of our
installations – it’s the best policy not just for ourselves but for our
customer,” Jamie explains.
“We’ve got multiple smart card readers, Padde 2000
strikes – everything is the same at all the sites so we only have to carry one
of anything and the customer only needs to get used to one of anything.
“Our installation at Cradle Coast Water is built around a
series of standalone Challenger panels across 13 sites and supported by a
single user base that allows a tech to walk into any of the sites and be
identified on one central system,” Jamie explains.
“Each of the Challenger panels has a reed, a doorstrike
output and a sensor input – these sites are small so that’s all there is to it
from an installation point of view.”
But things are more complicated than they seem. Two of
Cradle Coast Water’s sites have a combination of properties that disallow use
of standard sensors. Face to face with the huge 500kW General Electric
Motor-driven centrifugal pumps that haul the River Forth up from its bed to a
series of reservoirs above Devonport, these challenges become obvious.
According to Jamie, the problems in the River Forth pump
house were apparent from the word go.
“We started out using a high quality dual technology
sensor but the challenges of the environment were too much for it – on the
first day that sensor false alarmed 13 times and it was obvious we’d have to
come up with something special.”
Jamie says that special something was the Rokonet
WatchOUT sensor from Direct Alarm Supplies and he says the sensor has been an
excellent solution from the moment it was installed – there has never been a
single false alarm at any of the sites.
“The big deal with these pump houses is that the huge
motors create whirlpools of fast moving hot air,” Kaye explains. “The motors
turn on and off many times throughout the day to top up the reservoirs and that
initial startup is extremely difficult for alarm sensors to handle.
“The hot wind from the big electric motors just goes bang
as the pumps power up – if you’re in there working it’s like a mini cyclone,”
Jamie says.
“Not all the pump houses needed the Watchout and at
present we have it in 2 locations – it depends on the physical configuration of
the pump houses themselves. The small buildings with the biggest pump motors in
them are where we’ve installed WatchOUT.”
According to Jamie, even though he’s turned the
sensitivity settings on the sensors down to about 50 per cent to build in
additional environmental tolerance, the WatchOUT detectors still function
perfectly.
“Even when the pump engine is on and the WatchOUT sensor
is challenged by the hostile environment my walk tests show the sensor is
detecting movement instantly – when you consider the fact the best dual
technology sensors were unable to handle this installation that’s good – that’s
really good,” Jamie says.
“How the sensors don’t actually go off when the pump
motors start I don’t know.”
Features of WatchOUT
The strength of WatchOUT is based around the sensor’s 2
microwave sensors and 2 PIRs which between them give the processors a lot of
data. WatchOUT exercises Selective Event Recognition to distinguish between
false alarms and real site intrusion events. The Selective Event Recognition is
enabled by Rokonet’s Digital Correlation Technology which compares the signals
of 2 PIR channels with separate optics to ensure that only targets creating a
similar and correlated signal in both PIR channels will trigger an alarm. This
eliminates false alarms from rapid temperature changes, headlights, wind gusts
and big pets. Things like headlights and large dogs aren’t an issue for Cradle
Coast Water but wind gusts and major temperature changes are.
Central to Digital Correlation Technology is the fact
each of the PIRs has a separate lens creating a vertical interlaced detection
pattern. It’s a design that offers significant advantages over other twin
element PIRs which can go into alarm if the 2 separate PIRs false alarm for
completely different reasons.
Another strong feature of WatchOUT is Sway Recognition
Technology which uses 2 Microwave channels for recognizing and excluding
swaying objects such as bushes or tree limbs. This sway recognition is
facilitated by the 2 microwave sensors that enable the unit to distinguish
between microwave pulses of approaching or receding targets so they can work
out the net distance away an object is. In the pump houses the microwave
component gives strong support to the PIRs when the pump motors spool up.
The IP-65 WatchOUT is easily able to handle the
aggressive internal environment at Cradle Coast Water, which includes open wall
vents, the potential for dust accumulation and plenty of insect life.
Anti-masking protection is achieved by 4 active IR channels that continuously
monitor and warn of lens masking attempts. These same IR channels provide a
dirty lens alert via a separate output that sends a signal advising the lens
needs cleaning.
As Jamie explains, all the sites are monitored by
Tasmanian Combined Monitoring over PSTN lines.
“Where there are no PSTN lines we’re monitoring the
system using a SED-62 GSM dialler supplied by DAS and built by Sean Cronin,” he
explains. “This solution allows upgrading to something like GPRS in the future
– you just use a modem update kit and do a modification program and upgrade
them like that.”
Most important of all, Jamie says, there were no problems
with the installation – he says if any one thing stood out from an installation
point of view at Cradle Coast Water it was the fact the doors varied between
the sites – that was all.
“We have tried to maintain consistency with our system
components but the different door styles has made that harder – we’re using the
Padde 2000 electric strikes from DAS and have had no problems with them.
Meanwhile, Cradle Coast Water’s infrastructure services
manager Peter Williamson says the organization has been very happy with the
installation and the WatchOUT sensor.
“We’ve had no problems with the system or the sensor –
they’re working very well indeed,” he says.
Gear installed at Cradle Coast Water
* Rokonet WatchOUT sensors
* Challenger panels
* Padde 2000 electric strikes
* SED-62 GSM modems
* Installer: Complete Security
* Supplier: Direct Alarm Supplies.
