Perimeter Surveillance Lighting (CAST)By Brian Rhodes, Published on Sep 03, 2012
Protecting perimeters is a key component of effective security yet can be difficult because they are often poorly lit. Bad lighting not only helps adversaries hide, it also compromises the effecitiveness of surveillance systems. One can add street lighting but that can get expensive and become a big project. To address this, a new perimeter lighting product is gaining attention. In this note, we review the product, comparing the pros and cons compared to traditional products such as street lamps and white light LEDs.
CAST's "LED Perimeter" lighting fixtures are pole/stake mounted, all weather units. The target application for the units is installation on security fencing, and each fixture is designed to illuminate at 20 to 30 foot section.
The fixtures are powered from a 24 VDC power supply, but fixture input voltages can range from 24 V down to 10 VDC. This attribute allows very long lighting runs, up to 500 feet with 17 fixtures.
Other attributes of the CAST perimeter system include:
- Light Output: Each fixture produces 265 lumens in 20 - 30 foot radius
- Long Life: White LEDs rated to last 54,400 hours, or about 10 years. No maintenance is expected beyond cleaning lenses.
- Price: Fixtures cost about $150 each, and a 300VA power supply that can light up to 40 fixtures costs about $300. A higher powered 600VA power supply (up to 80 fixtures) costs around $400.
- Flexible Installation/Operation: The power supply includes a timer/ and has a photocell trigger input. Wiring a motion detector in series with the light circuit can provide alternate triggers. The low-voltage cabling can be run inside fence runner sections without violating NEC code. Even when trenching is required, low voltage lighting wiring requires shallow 6" trenches compared to high voltage lighting conduit that requires deeper (up to 18"), larger trenches.
- Dark-sky Compliant Design: Fixtures do not contribute to light pollution or glare that can interfere with video surveillance. Down cast design meets FAA requirements for use around airports.
- Solar Power: At the current time, CAST does not offer a solar panel power option for the series, however the company is still developing the product development roadmap.
This 'low voltage' lighting system departs from traditional 'high voltage' lighting in two major areas:
- Eliminates requirement for licensed electricians during specification and installation.
- Much lower light intensity output compared to streetlights.
Because the CAST system operates on 24 VDC, there is no code requirement for licensed electrical workers to design and install the product. In some cases, this may provide the opportunity for security integrators to specify and install these products without subcontract as a part of lighting enhancements during surveillance design.
Impact on Surveillance
The lower intensity output may be an advantage in some surveillance applications, and the overall dispersion of light from many smaller fixtures is more consistent over a broad area than a single high-intensity light source. The manufacturer claims that the downward cast and even dispersion of lighting from the CAST system eliminates glare issues that can interfere with video surveillance, but we have not tested the system and can not verify these results.
This may reduce cost of adding lighting by ~50% compared to traditional high-voltage stret lighting.
Since a typical high-voltage pole light will illuminate about ~75-100 feet of fence, 3 or 4 CAST fixtures are required to span the same distance. While the purchase price and installation cost of a high-voltage pole light costs ~$2,000, the equivalent number of CAST fixtures will cost ~$300 USD installed, for a total of ranging between $900 - $1200 installed.
For an example project involving 500' of fence, the cost of a CAST LED Perimeter system, including 17 fixtures, power supply, cabling, and installation labor will cost ~$5,000. When compared with the cost of 5 high voltage street lamps (covering the same 500' span), cabling, concrete footings, fixtures, and poles at ~$10,000.
White Light LED Options
Security illuminator manufacturers, like Bosch, Illuminar and Raytec have released white light LED units that are fairly similar to the IR units (except with visible light). For background, see our white light illuminator test results.
We suspect that white light LED spotlight units will be better at illuminating open areas, like parking lots, roads and runways but that CAST will be better for perimeters. Both options support low voltage power and mounting on existing poles or fences. While the white light LED spotlight units can cover farther ranges, at the near side to the illuminator subjects will be significantly overexposed (view our test results). However, longer range white light LED spotlight units will be less expensive than using a series of CAST units.
We recommend careful comparison between these two options for perimeter use as it is likely a significant tradeoff between cost and performance may exist between the two.
We see this product having the greatest benefit for amending gaps in perimeter lighting quickly, rather than alternative options that require capital construction. When additional illumination is needed at fence locations, instead of substantial trenching, pole installation, and high voltage electrical work being required - and being subject to length approval processess - the matter of amending lighting is greatly simplified and does not require disruptive construction or skilled trades labor.