CCTVs are generally sited to get the best possible image, making them vulnerable to both the weather and vandalism; so protection of the power and data cabling is vital to maintain continuity of the system.
According to Colin Legg, marketing manager for Flexicon, choosing the correct flexible conduit system depends upon its application and location. “You should conduct a hazard analysis considering factors such as ingress protection, location, accessibility, movement, the threat of vandalism and even exposure to UV light. For some applications aesthetics may also be a factor.” In recent times CCTV cameras have become common place for rail and airport terminals, businesses, shopping centres, motorways and other premises. Having cameras out of action seriously compromises the security of a network. The cabling is a potentially vulnerable element of the system and needs to be protected. “Depending on the application, there are a number of different flexible conduit systems that may be suitable. It is important to select the correct system for the job to achieve the best performance and to install it properly to ensure the ongoing integrity of the cabling.”
To illustrate the point we join Neil Ruston from Sitewatch on a typical project. The contracting company specialises in CCTV and access control solutions.
The building in question is a medium sized office block and the CCTV camera will monitor the building and its immediate surrounding area.
Potentially there are a number of flexible conduit systems that he can use for the cables. We require a 20mm radius to protect the cabling and are considering four product options from Flexicon. A highly flexible FPI nylon system; FSU which has a galvanised steel core with PVC coating; LTP which is a liquid tight conduit with steel core and PVC coating and LFHUBRD which is similar to FSU but with a low fire hazard (LFH) coating and a stainless steel overbraid.
The latter conduit system is a popular choice particularly for the London Underground and other rail installations. It has a high mechanical strength, good flexibility, an IP rating of up to IP65, high abrasion resistance and very high tensile strength. The braided steel cover is also aesthetic to look at and will provide EMC screening.
For this office block application, Neil selects the FSU conduit which offers high mechanical strength and good flexibility. When used with compression fittings it has an IP rating of IP65.
Neil explains that if we had required a higher IP rating and/or if the conduit was exposed to direct sunlight then either the LTP or an FPI conduit could be used, which can offer ingress protection of up to IP69k and are UV resistant.
To cut the conduit to size, Neil clamps it, measures its length and uses a fine tooth hacksaw as recommended by Flexicon. The compression fitting is simple to fit.
After mounting the fixing bracket for the camera to the corner of the building, Neil draws the cable through the conduit while it is straight.
For this camera the conduit is fixed to the mounting bracket. Neil has used a reducer fitting to reduce the diameter of the aperture on the bracket from 25mmm to 20mm. He also uses a fibre sealing washer to maintain the IP rating. The conduit fitting is then simply screwed into place and tightened. He also secures the other end of the conduit to the power box using a swivel type fitting to make the installation easier.
With the job finished, Neil can put his tools away and leave satisfied that he has helped protect the office block for years to come. With the cabling also protected Neil has also ensured minimal or no downtime.
The CCTV camera installed for this application can pan, tilt and zoom within its own housing. Moving and rotating cameras require more flexibility for continuous movement. Simply putting a loop in the flexible conduit will allow such motion and swivel fittings will allow movement even after the fitting has been tightened.
Security cameras are a lucrative area of business for contractors. Potentially the cabling is the most vulnerable part of such installations so make sure that you protect it properly and ensure that the camera can go on protecting the public and businesses.
Flexicon has produced a free guide to conduit specification - contact us for further details.
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