Maricopa County Installs STC Fire Station Flashers with Optical Detection
TEMPE, AZ - 04/04/2012 - Maricopa County DOT (MCDOT) installed fire station flashers with optical
detection and direction specific pre-emption emitter at Station 131 in Sun
City, AZ during Q1 2012. The fire station driveway, located about 250 feet
from a nearby intersection, had no warning signals and an inoperable optical
detection system tied to the nearby intersection control cabinet.
Solar Traffic Controls worked with the county to provide a total of three
flashing beacon systems on the approach to the station. The application site
had a large median and two lanes in each direction. Two flashing beacons
were placed at one approach, on the median and one on the curb, to account
for various visible obstacles in advance of the curb unit. The other
approach required one flasher in advance of the driveway.
Each flashing beacon unit was based on the STC XSR product family and
included a radio receiver, control logic with an LCD screen and a DPC2000
integrated charge/flasher control with built-in night dimming. Each unit
included an omni-directional confirmation beacon strobe and a solar powered
system designed to meet the location, load and duty cycle of the project.
Additionally, each system included a self-test function to allow county
personnel to verify operation of each unit.
Originally, the station had an optical detector system on a pole at the end
of the driveway with a pre-emption emitter on the pole aimed at the detector
at the nearby intersection. However, the equipment was originally tied to
the controller at a nearby intersection. The conduit connecting the
equipment to the intersection had been cut several years ago and was never
repaired.
The original design was to use an AC system powered from the controller.
Once the conduit problem became apparent, an all-solar solution made sense
to meet the project timeline. The master unit consists of an optical
detector transmitter unit with a solar-powered system. The detector head is
a Tomar Strobe Switch with an additional amber LED detect confirmation lamp.
Once an exiting vehicle with pre-emption lamp on is detected, the control
logic transmits out an ON command to the flashing beacons. The signal is
repeated for redundancy thus ensuring success in transmission in noisy
environments.
Since the fire station is located near the intersection, but not all calls
require using the intersection, a secondary radio system to control the
pre-emption emitter function on the pole was included. When exiting, trucks
must head through the nearby intersection and the system is activated, the
driver may use a short range radio on the truck visor to activate the
pre-emption emitter on the detector pole thus giving an early pre-emption
signal to the intersection. Since the intersection has a 40 second "Don't
Walk" cycle the early activation helps get the intersection into pre-emption
earlier thereby speeding the fire station's response time when heading in
through the intersection.
Celebrating our 11th year designing and manufacturing solar-powered traffic
control systems. For more information on STC's products and services, please
stay here on our website or send an email to info@solar-traffic-controls.com
or call 480.449.0222.
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