Tag Archives: FIber Converter

SBUS Fiber Optic Revisited: FAQs

sbus_webinar_screenI conducted a webinar on November 16, 2015, titled Powerful and Simple! Flexible Design with SBUS and Fiber Optic to provide an overview of the Silent Knight addressable SBUS devices and how they provide flexibility for a variety of applications. I also presented the SK-F485C SBUS to Fiber Optic converter. This product provides a solution to the high risk of lightning damage and ground faults that often occur with wire runs between buildings.

Thank you for those who were able to attend this webinar. There were excellent questions and comments and I would like to address some of them in this blog:

  • A popular question centered on cascade and daisy-chain wiring of multiple SBUS devices. SBUS devices are addressable and provide flexible wiring configurations. Daisy chain, T-Tapping, and Home Run wire configurations are all acceptable methods. The fire alarm control panel will properly annunciate and report trouble events if there is a wire break with any of these methods.
  • Another popular question related to wire type and distances. Specifications call out for wire to be from 14 AWG to 22 AWG with a possible distance up to 6,000 feet. Wire can be of any type that meets NEC 760 fire power limited fire protective signaling cable.
  • Lastly, questions and observations arose about the specifications of the fiber optic cable. The SK-F485C uses 62.5 micron multi mode fiber optic cable at 115.2K bits/second. Fiber connections are ST connectors and the cable distance is up to 1 mile (5,280 feet).

If you have any questions or need assistance with an application, please contact the Silent Knight Applications department at 1-800-446-6444 or Jack.Grones@Honeywell.com.

Do you know that you can download and view this and other previously held Silent Knight webinars? Click here to access our webinar library page.

 

About the Author
Mark Indgjer is a Product Marketing Manager with Silent Knight.  Mark joined Silent Knight in 1988 and is responsible for new product development, product marketing and much more.  Mark is also NICET Level II certified.​

Reducing Fire Alarm System Vulnerability with Fiber Optics

Since we are in the heart of lightning season, I would like to visit a topic that has been discussed in the past – fire alarm system vulnerability. Electrical surges and ground faults due to storms can wreak havoc on fire alarm systems, especially multi building installations using copper wire.

Fortunately, there is an option available to assist in alleviating these vulnerabilities: fiber optic cable. Because fiber optic cabling uses glass or plastic strands, there is no need for grounding. Since grounding is no longer required, electrical surges and ground faults are virtually eliminated because there are no earth ground differentials.

Silent Knight offers a solution using the SK-F485C fiber optic converter. This device converts the SBUS copper run to fiber optic. The diagram below illustrates how the conversion is accomplished linking the fire alarm panel to a distributed addressable power supply. It is important to note that the SK-F485C is U.L. listed with the IntelliKnight line of addressable fire alarm panels.fiber conversion

 

When using the SK-F485C, please keep in mind required fiber optic specifications:

  • Duplex ST connectors for the TX and RX connections
  • 62.5 microns
  • Multimode
  • Data rate = 115.2K byte/second
  • Maximum attenuation of 5.5db

Do you have installations where the SK-F485C would be helpful? Need applications and support assistance? Let us know in the comments section below! Click here to download the SK-F485C data sheet.

 

About the Author
Mark Indgjer is a Product Marketing Manager with Silent Knight.  Mark joined Silent Knight in 1988 and is responsible for new product development, product marketing and much more.  Mark is also NICET Level II certified.​