I N N O V A T I O N A N D F L E X I B I L I T Y
9.10 Bend Radius for FU and m/d
In any installation the installer should be familiar with the bend radius of the product he is using so that if he sees something which breaks
the specification he should remedy it and report the problem. For instance, it is not acceptable to bend a 2fu to a radius of 30mm nor is it
acceptable to bend an 8/6mm microduct to 50mm. Use the reference chart detailed below and ensure that the design limits of the specific
product are not broken.
Where multiple products are used in combination always take the largest min bend radius of the set.
Parameter
Radius
Notes
G657 Optical Fibre
refer to specifi cation
Attenuation & probability of fracture < 1 in 1,000,000
G652 Optical Fibre
30mm
Attenuation & probability of fracture < 1 in 1,000,000
2 & 4 Fibre Unit
50mm
Satisfactory trials to 1,000 hrs at 65°C
8 & 12 Fibre Unit
80mm
Satisfactory trials to 1,000 hrs at 65°C & limiting fi bre strain (further work?)
5/3.5mm m/d
50mm
Kink resistance fi gure
8/6mm m/d
80mm
Kink resistance fi gure
Tube Assemblies
> 80mm
See individual specs e.g. 24-way 3/2.1 DB = MBR of 330mm
Plant Radius
50mm (TDC, Tyco-FOSC)
Other joints, FIST, Hellermann UFC normally larger
Blowing Radius
300mm in-route
1 bend per 100m to guarantee nx100m blow
9.11 Microduct Calibration & Testing
Tools Required
Emtelle approved Air Compressor
Dispenser
Airflow Meter kit
8 – 5mm Reducers
5mm m/d End Cap
Corresponding Air Flow Chart for Primary m/d
To enable a m/d to be fully tested, the following 3 tests must be done in the sequence shown, on each microduct in a microduct assembly after
installation.
Care should always be taken when working with compressed air and pressurised m/d systems.
The three Sequences described in this manual are as follows:-
a)
Air fl ow Testing
To check that the correct air flow has been established over a given length of microduct. This also checks that the m/ds have been coupled
together in the correct sequence.
b)
Pressure Testing
To check that there are no connector or m/d leaks in the route.
c)
Continuity Testing
To check that the bore of the m/d is not reduced for any reason.
ALWAYS CARRY OUT THE 3 TESTS IN SEQUENCE, i.e. m/d AIR FLOW TESTING, PRESSURE TESTING AND THEN
CONTINUITY TESTING.
9 Fibre blowing
“This document is intended as a guide only. Whilst the information it contains is believed to be correct, Emtelle can take no responsibility for actions taken based on the information contained in this document. Emtelle reserves the
right to make changes to this document without notice. All sales of product are subject to Emtelle’s terms and conditions of sale only, which can be found on Emtelle’s website.”
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