This article originally appeared in the April 2022 issue of Security Business magazine. When sharing, don’t forget to mention Security Business magazine on LinkedIn and @SecBusinessMag on Twitter.
Modern access control systems provide key protection to buildings and people. Planning and building a system using quality, properly rated cable will help guarantee long-term performance, a healthy return on investment, and most importantly, protection for people and property when it matters most; thus, choosing the right cable for an access control system implementation is paramount for integrators.
In a basic wired access control system, four devices require continuous connectivity: A card reader, a door strike, a request-to-exit sensor, and a door contact. Each device has unique electrical requirements that determine what cable is used to connect to the access control panel, which monitors or controls each component of the system.
Card Reader: Able to sense and transmit credentials to the control panel for entry permission, the card reader cable must transmit the signal with minimal distortion, so the cable employs a protective shield. Traditional Wiegand card readers use six 22 AWG bare copper conductors with a foil shield.
Door Strike: The electromechanical workhorse of the access control system requires more power than other components. A cable with heavier gauge, typically 18 AWG bare copper conductors, delivers the necessary power with minimal voltage drop.
Request-to-Exit: The RTE device senses the motion of people ready to exit and signals the control panel to release the door strike. The RTE requires four 22 AWG bare copper conductors for power and signal transmission.
Door Contact: The door contact, the simplest component of the system, monitors whether a door is open or closed. A simple 22 AWG two bare copper conductor cable supports the door contact’s function.
4 Considerations for Cable Evaluation
When creating a reliable access control system, quality must be top priority. Without it, systems can experience unreliable performance and premature failure – threatening end-user security and safety, increasing total costs, and risking the integrator’s reputation.
Here are four quality markers to consider when choosing an access control cable for long-term, reliable performance:
1. Pure Bare Copper Conductors: Compared to other conductors, copper installs more easily and creates more durable connections. It also limits resistance and voltage drop to offer more dependable performance. The National Electric Code (NEC) requires pure copper conductors for all communication cables, including card reader cables, for system compliance.
2. Cable Shielding: Electromagnetic interference threatens higher-frequency signal transmission, and noisy environments can disrupt even the most basic signals. The card reader cable should include a shield to protect its data signal transmission integrity. In environments with higher levels of interference, shields may benefit all cables.
3. Cable Listing: Cable with a UL or ETL listing certifies compliance with important safety and flame standards by a third-party reputable partner. A listing demonstrates the use of high-quality materials and compliance with safety requirements. The dangerous decision to install unlisted cable can threaten the device, personnel, and environmental safety.
4. Cable Rating: Not all cables can be used interchangeably within a building’s space. Cable ratings dictate where a cable can be installed; and not following these guidelines violates NEC. This also applies to cables installed outdoors. Review a cable’s specs to determine suitability for outdoor installation and which specific outdoor ratings it carries. No single outdoor rating covers all conditions, so it is important to choose cable most suited for the installation environment.
The Cable Selection Process
The layout of a system and its included devices often dictates which cable should be used. As a starting point, installers should always check a device’s datasheet for any manufacturer requirements and recommendations. This can help guide the cable selection process and ensure cable meets device specifications.
As technologies advance, larger gauge sizes are sometimes required to support increased power needs. Larger gauge sizes also help limit voltage drop and resistance for longer cable runs. While run lengths for most systems should not exceed 500 feet for optimized system performance, failing to use the correct gauge size can cause incomplete signal transfer and system malfunction for longer runs.
Installers also have the choice between using separate cable components for each access control component or a bundled solution that combines all cables into one. While separate cables typically cost less than bundled solutions upfront, bundled access control cables reduce labor time and costs, and add convenience.
One advantage of separate cables is flexibility for customization based on device needs. Factory-bundled cables may not have the right combination of cable components for every access control system. Reviewing device and cable specs will help determine if bundled access control cables fit the needs of a system.
Taking the installation environment into consideration is a critical step when determining which cables are most appropriate for your job.
Some bundled access control cables include an outer jacket to contain the inner cable components, while others use different methods such as special twisting to prevent the components from separating during pulls. The unjacketed variety excels in new construction or other environments with limited obstructions. With no outer jacket to strip, this cable decreases material costs and reduces entry point wiring time.
The jacketed variety maneuvers more easily around corners without getting snagged on nails or other protrusions for superior protection in more difficult installation environments such as complicated retrofits.
Cabling Needs for Integrated Systems
When integrated with other systems such as video surveillance, life safety, and building management, the capabilities of access control systems proliferate; however, as system complexity increases, the need for a strong, reliable network grows more critical.
An integrator must always coordinate closely with IT personnel to ensure a building's network properly supports an access control system's unique requirements – including the network cabling.
Networks should be built with verified category cable. As technologies continue to advance, new devices will require increased data capabilities and faster network speeds. For example, Cat 6 and Cat 6A cables help create a network that is easily adaptable to future needs. Planning for future technology integration or business growth maximizes return on investment and limits the need for premature rip outs and reinstallations.
Regardless of the performance rating, it is important that the category cable includes the following characteristics:
Pure Copper Conductors – The NEC requires pure copper conductors for communication cables. Pure copper conductors limit resistance and voltage drop, and they install more easily and create more durable connections.
UL/ETL Listing and Verification – Listings indicate safety. Cable verifications ensure performance. Listings and verifications from a third-party reputable partner like UL or ETL help system designers and installers identify quality cables that will provide the necessary safety and performance.
Daniel D. Dunar is Product Manager for Genesis Cable, a division of Resideo Technologies. Visit www.resideo.com/us/en/pro/genesis to learn more, or request more info about Resideo at www.securityinfowatch.com/12422908.
