Tag Archives: optical fiber cable

Understanding Optical Fiber Cable Fire Ratings


As we all know, optical fiber cables shall be listed as suitable for the purpose. Cable usually be marked in accordance with NEC (National Electrical Code) Table 770.19. Most manufacturers put the marking on the optical fiber cable jacket every 2′ to 4′. The code does not tell you what type of cable to use (such as single-mode or multi-mode). In fact, It tells you this cable can be resistant to the spread of fire. This text will introduce the knowledge of optical fiber cable fire ratings and help you choose the right fiber for your applications.

Types of Fire-proof Optical Fiber Cable

There are three kinds of cable jacket fire ratings: plenum, riser and general purpose. Plenum cables are held to the most stringent testing of any of the cables rated by the NEC, rated for both flammability and smoke generation. Riser cables are subjected to flame tests only, and are not held to as high of a standard as Plenum rated cables. General Purpose cables may be used anywhere in commercial buildings other than areas where Riser or Plenum cables are required. Besides, optical fiber cable can be divided into nonconductive and conductive according to NEC. Nonconductive cables contain nothing that can conduct electricity, so will not accidentally energize or be energized even when closely associated with electrical conductors. Conductive cables contain noncurrent-carrying conductive members such as metallic strength members, metallic vapor barriers and metallic armor or sheath. Therefore, according to these three cable jackets and whether the cable is nonconductive or conductive, these fire-proof optical fiber cables can be divided into following several types.

Cable Marking Type
OFNP Nonconductive optical fiber plenum cable
OFCP Conductive optical fiber plenum cable
OFNR Nonconductive optical fiber riser cable
OFCR Conductive optical fiber riser cable
OFNG/OFN Nonconductive optical fiber general-purpose cable
OFCG/OFC Conductive optical fiber general-purpose cable

Optical Fiber Cable Fire Ratings

There are three levels of fire resistance in terms of optical fiber cables. The ratings are hierarchical. For example, from a fire resistance standpoint, a higher rating can be substituted for any lower rating, but not vice versa. Also, nonconductive may be substituted for conductive, but not vice versa. The fire ratings of optical fiber are showed below, from most stringent to least.optical fiber cable fire ratings

Choosing the Right Fiber for Your Application

In terms of different cable fire ratings, there are different kinds of optical fiber cables. So choosing the right one becomes a difficult problem. Usually, for those planning or installing a fiber network, the key point of UL 1651 is to help ensure you select the right fiber for your particular need. These are described in article 770.19 of the NEC, but here are some common measures:

  • For a small, in-building deployment, using a riser – OFNP, OFCP, OFNR, OFCR,OFNG, OFCG, OFN, OFC
  • Within an existing, fabricated duct inside a building – OFNP, OFCP
  • In a plenum space that is used for environmental air inside a public building – OFNP, OFCP
  • Inside a fireproof shaft using a riser within any type of building – OFNP, OFCP, OFNR, OFCR,OFNG, OFCG, OFN, OFC
  • When using a metal raceway for in-building deployments covering multiple floors and rooms/apartments – OFNP, OFCP, OFNR, OFCR,OFNG, OFCG, OFN, OFC
  • For vertical runs between floors within a riser – OFNP, OFCP, OFNR, OFCR
  • Within a riser cable routing assembly inside a building – OFNP, OFCP, OFNR, OFCR
  • For in-building deployments with routing only on 1 floor – OFNP, OFCP, OFNR, OFCR,OFNG, OFCG, OFN, OFC

Related Article: Understanding Fiber Optic Cable Jacket & Fire Rating

FiberStore Announces Availability of a New Product -Return Loss Tester JW3307B


Summary: FiberStore announced the launch of a new return loss tester series JW3307B with enhanced features of high accuracy, compact appearance, stable and reliable test index, etc.

FiberStore is pleased to announce a new return loss tester – Muti-mode Loss & Insertion Loss Test Station JW3307B, which is a high performance loss test station that is designed specially for Optical Passive Components production Test and Lab Test.

The multimode interpolation return loss measuring instrument is specially used in the optical fiber cable and other fiber optic passive devices, optical active device and optical fiber communication system of insertion loss and return loss test.

At the moment, this new return loss tester combines three different working modes as a return loss meter, optical power and loss meter and a stable laser source in one test station.

JW3307B is a special circuit designed, with large dynamic range and weak signal accurate monitoring analysis, it can provide USB communication function, automatic storage of data.

“This highly accurate return loss tester used Two LCD displays, and efficiently reduced eye strain of users. Besides the leakage design of optical power meter module and light source module also greatly reduced the operation procedures” commented Li Longqing, product manager, fusion splicer systems for FiberStore.

Standard configurations of this JW3307B tester includes the main body, power supply cable, the interface adapter ( FC/SC/ST/φ 2.5/φ 1.25), User Manual, FC/APC-FC/APC reference patch cord, Scrambler, Extinction Module, Cleaning Cotton Stick, Fuse, USB Cable, PC software, Foot Pedal. If you want to know more about this MM Return Loss & Insertion Loss Test Station JW3307B, visit www.fs.com or contact us by sales@fs.com