Outdoor Fiber Optic Cable
Once a cable leaves the building, the design problem changes completely. Fire behavior stops being the governing concern and water ingress, ultraviolet exposure, crush loading, rodent attack and pulling tension take over. The Heizka outdoor range answers those with stranded loose-tube construction, water blocking inside and outside the tube, and a black polyethylene sheath. Two variants are published: an all-dielectric non-metallic design and a corrugated steel-tape armored design.
Water Blocking and the Loose Tube Principle
In loose-tube construction the fibers float inside an oversized tube rather than being gripped by a tight buffer. That excess fiber length lets the cable stretch under tensile load and contract in cold weather without transferring strain to the glass, which is why loose tube is the standard choice for outside plant. Both Heizka outdoor variants are water-blocked: the non-metallic version uses water-blocking compound filled both inside and outside the loose tube, and the steel-tape version uses water-blocking tape together with filling compound. The purpose is to stop water that penetrates a damaged sheath from migrating along the core and reaching a splice enclosure.
The sheath on both is black polyethylene. The non-metallic series is published with excellent ultraviolet prevention, which is what allows aerial and exposed duct-entry sections to survive years of direct sunlight without the jacket chalking or cracking.
Choosing Non-Metallic or Steel Tape Armor
The non-metallic series, model codes HEFOLNXX0PE, HEFOLNXX2PE, HEFOLNXX3PE and HEFOLNXX4PE for OS2, OM2, OM3 and OM4 respectively, is an all-dielectric CSM design. With no metallic element anywhere in the cable there is nothing to bond or ground, nothing to attract a lightning strike into a building, and no exposure to electromagnetic influence. That makes it the default where the route runs near power infrastructure, on to a rooftop, or into a facility where introducing a metallic path is unwelcome.
The steel-tape series, HEFOLSXX0PE through HEFOLSXX4PE, adds corrugated steel tape armor over the core together with two parallel steel wires of 0.8 ± 0.1 mm as strength members. It is the variant to specify for direct-burial runs, duct installations and routes exposed to rodents or heavy mechanical stress, and it is published for long-distance communications.
Published Mechanical and Environmental Data
Full mechanical figures are published for the steel-tape series:
| Property | 2–8 core | 10–12 core |
|---|---|---|
| Loose tube (PBT) diameter | 2.0 ± 0.1 mm | 2.1 ± 0.1 mm |
| Cable diameter | 7.5 ± 0.2 mm | 7.8 ± 0.2 mm |
| Cable weight | 57 kg/km | 60 kg/km |
| Tensile strength, long term / short term | 600 N / 1500 N | |
| Crush resistance, long term / short term | 300 N/100 mm / 1000 N/100 mm | |
| Minimum bend radius, long term / short term | 10 × cable diameter / 20 × cable diameter | |
| Operating and storage temperature | −40 °C to 70 °C | |
Fiber core range for the steel-tape series is 2 to 12 cores. Both outdoor series are built against ISO/IEC 11801, the ITU-T G.651, G.652, G.655 and G.657 recommendations as applicable, and IEC 60793-1, 60793-2, 60794-1 and 60794-3.
Frequently Asked Questions
What pulling tension can I apply during a duct pull?
For the steel-tape series the published short-term tensile rating is 1500 N and the long-term rating is 600 N. Size your winch and breakaway swivel to the short-term figure and keep the installed cable well under the long-term figure once it is at rest.
What bend radius should the sheave and duct bends respect?
Twenty times the cable diameter during installation and ten times the cable diameter once installed, for the steel-tape series. At 7.5 mm diameter that is roughly 150 mm dynamic and 75 mm static.
Do I need to bond and ground the steel-tape version?
The steel-tape construction contains metallic elements — corrugated tape and two steel wires — so it must be treated as a metallic outside-plant cable and handled per your grounding and bonding practice at each building entrance. If that is unwelcome, specify the non-metallic all-dielectric series instead.
Where does the outdoor cable stop and indoor cable begin?
Transition at the entrance facility. Terminate or splice the outdoor cable in an enclosure at the point of entry and continue inside on Indoor Fiber Optic Cable with its LSZH jacket, using a patch panel with an integrated splice tray from the Fiber Optic Accessories range.
Tell us the route, burial or duct method, span length, core count and grade, and we will return matching model codes and pricing. Get started at contact us, see the full optical range under Heizka Fiber Cable, or download test data from documents.
