Fibre Patch leads do they need to be bend insensitive?

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“Fibre Patch Leads” do they need to be bend-insensitive?  What a great question!

 

Fibre Patch leads are quite sensitive to stress, with tight bends being a particular problem. Once fibre patch leads are overly stressed by bending some of the light is lost, causing high attenuation. Even though the cable coating is designed to prevent as much loss due to bending as possible it remains a real issue for installers.

 

So what does Bend Insensitive patch leads mean?

Bend Insensitive is just another term for “reduced bend radius” really, “Bend Insensitive” sounds better, doesn’t it?

 

How does the standard bend radius differ to that of the bend-insensitive patch leads?

Basically, at the time of manufacture of Bend Insensitive cable, another layer of glass with a lower index of refraction is added around the core to ensure the light remains reflected back into the core even if the standard bend radius has been exceeded.

 

Other terms used in the industry to refer to this extra layer are either the “trench” or “moat”.

Do not get this confused, Bend Insensitive Patch Leads still have a bend radius as the chart below demonstrates

 

Bend Insensitive Patch Leads

 

Note: refer to our video https://www.andcorp.com.au/fibre-patch-cable-bend-insensitive/ for more detailed information

 

The chart above relates to G657 glass for Singlemode fibre patch leads as per ITU-T recommendation.

ITU stands for International Telecommunication Union and this union co-ordinate standard which are related to the telecommunications industry.

 

G657 is further split into two categories:-

As you can see from the chart the G657 glass is further split into two Categories:

Cat A – Category  A – Fibre for Access Networks being

-10mm for G657 A1 and

– 7.5mm for G657 A2

 

CAT B– Category B – Fibre for short distances at the end of Access Networks being

–  7.5mm for  G657 B2 and

–  5.0mm for G657 B3

 

What does this mean when it comes to bend insensitive patch leads?

The below chart shows the Standard G652 Glass bend radius compared to the G657 Bend reduced fibre bend radius for  singlemode fibre patch leads.

 

Bend Radius

The advantages are now clear to see.

 

Other benefits of Bend Insensitive Fibre patch leads (BIF):-

– less attenuation means lower losses – more cable, less space required – simplifies instalment – high density in patch panels

– quite flexible

– reduces roll out cost

– less rework

 

What are Anderson Bend Insensitive Singlemode Fibre optic patch leads?

The Anderson Bend Insensitive or Reduced Bend Radius Fibre optic patch leads adhere to the ITU-T G657 Recommendation.

Whilst we have been making our products for a number of years now using the G657 A1 recommendation we have now released a product that adheres to the G657 B3 recommendation. Thereby providing a bend radius of 5mm.

 

What is the Anderson glass of choice for bend-insensitive fibre patch leads?

The 7.5mm product will be required for its ability to not only technically pass the G657 A2 recommendation, but it will do so with almost zero loss.

 

In addition to the above, Anderson Corporation offers a Lifetime Warranty on all of its fibre patch leads and our complete range of Bend Insensitive fibre patch leads are no different, also being offered with a Lifetime Warranty

Provided with a Low Smoke Zero Halogen Jacket these bend-insensitive patch leads are of the highest standards in today’s market and are the leading-edge technology that is required by today’s users with particular emphasis on the FTTH market. You can choose from either LC, SC, a combination of both or whatever else you may decide. We can make a product to your specifications. Whether this is the boot colour’s, jacket colours or even different glasses – Anderson Corporation can be exceptionally flexible with our manufacturing.

 

https://www.andcorp.com.au/product/fibre-optic-patch-cables/

 

Conclusion:

Bend-insensitive fibre patch leads (or BIF) have obvious advantages. In patch panels, they should not suffer from bending losses where the cables are tightly bent around the racks. In buildings it allows the fibre to be run around tight corners in the ceiling or floor. It also can be run around doors or windows without inducing high losses. It’s also insurance against problems with installers who may not be aware of any bend radius issues. And maybe if looking into the future may cause fewer issues for you.