Daisy Chain Wiring White Paper. Don t Overspend On Your Electronic Access System - Daisy Chain Wiring

Transcription

1 Don t Overspend On Your Electronic Access System - Daisy Chain Wiring

2 Optimal Wiring Infrastructure Companies in all industrial sectors operate in a highly competitive economic environment. Whether in Banks and Financial Institutions, Retail, Colleges and Universities, Commercial Building, Hospitals, Medical Clinics, Military Bases, Municipalities and luxury condos, boosting productivity has become more and more necessary. Reducing downtimes for repairs and failures, as well as better asset and energy management are key challenges to increase productivity. One solution to reduce the cost of time, labor and copper is a wiring technique called daisy chain. What is Daisy Chain Wiring? In electrical and electronic engineering a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring. Other than a full, single loop, systems which contain internal loops cannot be called daisy chains. Daisy chains may be used for power, analog signals, digital data, or a combination thereof. The term daisy chain may refer either to large scale devices connected in series, such as a series of power strips plugged into each other to form a single long line of strips, or to the wiring patterns embedded inside of devices. Using the daisy chain technique with central power saves on the need to use 110VAC circuits locally, significantly reducing electrician costs. Since each power supply draws the same power, it s rated for whether the power is fully loaded or not. The general power consumption would be less with daisy chain wiring. Signal Transmission For analog signals, connections usually comprise a simple electrical bus and, especially in the case of a chain of many devices, may require the use of one or more repeaters or amplifiers within the chain to counteract attenuation (the natural loss of energy in such a system). Digital signals between devices may also comprise a simple electrical bus, in which case a bus terminator may be needed on the last device in the chain. However, unlike analog signals, because digital signals are discrete, they may also be electrically regenerated, but not modified, by any device in the chain. Daisy Chain Wiring vs. Home Run Wiring Unlike typical home run, daisy chain wiring provides exponentially more capability, flexibility, and reliability. Homerun wiring is taking the wire from each component back to the control panel instead of going from one component to another with the wire before finally going back to the panel. 2

3 The term Home Run Wiring has come to mean having a central location like a closet, with all your home electronics (cable box, DVD player, A/V receiver, VCR, modem, ethernet, etc.) where all the signals are distributed from. Many times the cables are all bundled together, and every location gets a drop with all the services. The drops are generally made without splicing the cables anywhere to reduce problems. In areas such as a tradeshows daisy-chained electrical is a big time and cost saver. With an exhibit that has daisy chained electrical one would only need a single electrical source with the required amperage / wattage for the equipment. This would mean that only one cut would have to be made in the carpet to fish the electrical line though the carpeting as opposed to several cuts that would have to be made to supply each item individually. This saves the life and look of the exhibitors carpeting. Also, each additional line of electrical power comes at a cost, so having fewer power supplies is a much more cost effective method of powering the exhibit area. The daisy chain wiring technique is exponentially more flexible and offers future local capability. When adding more devices in the field, both the communication and power already exists. Copper Savings There are several benefits to using a daisy chain in electrical sequencing. The first is that electrical wire is saved. With copper prices higher than ever and rising, cabling has become an expensive procedure. The price of copper has soared past previous records. Copper prices will advance 7.6 percent in 2013 from last year as demand in China, the U.S. and even Europe is forecast to rise amid a supply deficit for the metal, according to Morgan Stanley. 3

4 Copper Savings The bank projected copper prices to rise to $8,554 a metric ton, or $3.88 a pound, in 2013 from $7,952 a ton in 2012, analysts Peter Richardson and Joel Crane wrote in a report today. Morgan Stanley raised its Chinese copper demand forecast to 8.4 percent year-on-year from 6.7 percent and expected further 5 percent growth in Millennium Group s unique daisy chain wiring technique will save you a significant amount money in copper cable wire pricing and installation. Below you will find a case study illustrating how much money could be saved using daisy chain wiring as opposed to homerun wiring. Daisy Chain Case Study This is a functional case study of an access control dealer, Company X, was hired to install an access control system in a fictional Doctor s Office. What we are showing here is a scenario where a Doctor s office has requested a 5 door access control system to be installed. The diagram below reflects the average amount of copper wiring needed to install a 5 door access control system using Millennium Group s daisy chain wiring technique. Daisy chain wiring uses 3 wires; SCU, System Power and Lock Power. All wires are daisy chained from one door to the next: 45ft x 3 55ft x 3 45ft x 3 45ft x 3 135ft 165ft 135ft 135ft 20ft x 3 60ft The Math Door 1 is 45ft away from Door 2 45ft x 3 wires = 135ft Door 2 is 55ft away from Door 3 55ft x 3 wires = 165ft Door 3 is 45ft away from Door 4 45ft x 3 wires = 135ft Door 4 is 45ft away from Door 5 45ft x 3 wires = 135ft Door 5 is 20ft away from SCU, System Power and Lock Power 20ft x 3 wires = 60ft Total = 630 feet of Cat 5 copper wire 4

5 Home Run Wiring The diagram below reflects the average amount of copper wiring needed to install a 5 door access control system using other access control company s home run wiring technique. Home run wiring uses 4 wires; Lock, Door Position Switch, Request to Exit and Reader. All wires have to be run back to the Door Control Unit: 840ft 620ft 440ft RTE RTE RTE RTE 260ft RTE DPS DPS DPS DPS DPS ft Door Control Shipping Room Server Room Storage Room Back Door The Math Door 1 is 210ft away from Door Control 210ft x 4 wires = 840ft Door 2 is 165ft away from Door Control 165ft x 4 wires = 660ft Door 3 is 110ft away from Door Control 110ft x 4 wires = 440ft Door 4 is 65ft away from Door Control 65ft x 4 wires = 260ft Door 5 is 20ft away from Door Control 20ft x 4 wires = 80ft Total = 2,280 feet of Cat 5 copper wire The Final Product Since the Office Manager of the doctor s office decided to go Company X, using the Millennium Group daisy chain wiring technique just saved them a lot of expensive copper wire. That s not to mention the time saved by the technician who did the install. It s estimated the final cost of install using the daisy chain technique over home run wiring is 30% less. With this particular project, the doctor s office was charged the industry average of $1,301 per door for 5 doors. Company X billed the final installation at $6,505. If the doctor s office had decided to go with Millennium Group daisy chain wiring technique, they would have paid $4, That s an incredible savings of $1,951.50! 5

6 If one device goes down don t they all go down? Some people think the downside of daisy-chained electrical is that if one device fails, all of the downstream devices will fail. An example of this failure is seen when Christmas tree strung lights fail. When one of the strung lights fail then all the lights following it fail. Not until a replacement light is completed will the rest of the string of lights become illuminated. If this happens with electrical components that burn out or blow fuses then the component would have to be replaced to get the other components down the line to work properly. This is simply not true with Millennium Group daisy chain wiring. The daisy chain architecture consists of a blockage module and daisy chain (serial communication) blockage sensors. Each module and sensor displays on the virtual terminal indicating critical system parameters for the selected communication loop. Advanced diagnostics is a value-added feature to assist in quick identification of system issues relating to sensor, communication, and power issues of the daisy chain wiring. Alarm screens alert of system issues and exact problem location. The daisy chain system s two-way communication allows for continued operation with pinched wires or breaks in communication lines to minimize downtime in the field; there is no end of line termination. Aren t the control panels now compromised because of their location? Another common misunderstanding is that since the daisy chain wiring technique requires control panels to be in proximity to each door, anybody can now access them and break in. This is an untrue statement. Our electronic tamper-proof lock box system is designed to securely house a control panel and prevents tampering. Featuring an interlocking keyed front door, the lockbox can prevent unauthorized access to a door s control panel and vandalism. If anyone ever does try to access the lock box, an electronic signal with be sent to the central workstation documenting the event. It s a lot harder to vandalize when the control panels aren t in a central location as with home run wiring. Isn t it now more difficult to service the control panels since their at each door? It is in fact much easier and safer to service systems having the daisy chain wiring configuration. Since the control panels and power supply are at each door, it is not necessary to run back and forth between the control panel and power supply. With home run wiring, the power supply for the door your trying to service can be on a completely different floor than the control panel; adding up to more labor and costs. 6

7 Since daisy chain wiring does not use Power over Ethernet isn t it unsafe? Implementation of a PoE solution involves numerous challenges. First and foremost, the solution must closely comply with communication and safety standards. The PSE is the side responsible for most technological aspects related to safety. UL does not even recognize PoE for life safety. With PoE there are many safety issues to take into account. PSE must not damage existing cabling infrastructure nor non-powered devices connected to it. Therefore, power must only be provided when PoE-enabled terminals are detected and must be terminated quickly after their physical disconnection. PoE systems must be protected from current overloads and short circuits scenarios. Thermal protection should be kept to avoid flammability. Protection of PSE s port from crossedconnection to an adjacent one must exist. When implementing a PoE system, numerous physical infrastructure limitations must be taken into consideration. CAT-5 cables commonly used in Ethernet infrastructure, for one, may carry voltage levels of no more than 80 Vdc, and RJ-45 connectors are rated at a maximum of 250 Volts and 1.5A, while safety standards rate voltages below 60 Vdc only as SELV (Safety Extra Low Voltage). About Millennium Group For over 50 years, Millennium Group has offered the most technologically advanced access control systems on the market, specializing in solutions for education and healthcare. A pioneer in scalable web-based access control systems, servicing industries and organizations that require varying levels of restricted entry, Millennium Group is large enough to meet all access control needs, but flexible enough to offer customized solutions and service. For more information about Millennium Group s complete line of access control systems, contact Millennium Group, Inc., 16 Tech Circle, Natick, MA 01760; ; or visit See how much Millennium Group can save on your next project by getting a FREE risk assessment with one of our security experts. Simply click here to sign up or call Are you an access control dealer? If so, click here to find out how much money you could save. 7

8 2013 Millennium Group, Inc. 16 Tech Circle Natick, MA P F