One of the advantages of fibre optic cabling is its ability to be joined several times in the same installation run. This is also helpful if you are in need of a fibre cable repair

1. Fibre Cable Repair. Can fibre optic cable be joined?
Fibre Cable Repair Options
One of the advantages of fibre optic cabling is its ability to be joined several times in the
same installation run. This is also helpful if you are in need of a fibre cable repair
Of course it is best if the joint or as the industry refers to them “Splice Points" are pre-
determined.
In many installations a fibre cable will be taken to a demarcation point and left coiled for
future installation by others. The future installation then involves installing an additional fibre
cable and splicing to the existing fibre creating a singular fibre connection cable.
Can Fibre Optic Cable be repaired?
Demarcation and splice points are a regular part of any fibre optic cabling installation.
However incidents sometimes occur and call for a broken fibre cable to be repaired and
joined to re-connect communication.
The investigation into whether the fibre cable is ok to be repaired depends on how it has
come to be broken and how much slack (spare cable) is on the existing link.
How do you fix a broke fibre cable?
Fibre Cable Repair One
In the event that there is plenty of spare cable the two parts of the broken fibre can have the
damaged ends cut off and prepared. These ends are then spliced together and secured in a
protection box which houses the fibre optic cabling connectors.
Fibre Cable Repair Two
Should the link cable have additional damage or not have any spare slack then a different
repair can be undertaken. In this situation the end are cut back to where the damaged has
occurred on each damage point. Then to reconnect the link a new piece of fibre cable is
inserted between the two points and spliced twice. Once to each end to again reconnect the
communication link.
How are Fiber Optic Cables spliced together?
There are a few different ways to terminate fibre cables but by far the most common and
professional is to use a fibre optic splicing machine.
Both ends of the cable are prepared and stripped back to exposure the glass core within the
outer sheathing. Then the ends are cleaned and cut / cleaved to create a perfectly sharp

2. straight end. Furthermore these ends are then placed into a plastic termination protector and
lightly pushed together
Once inside the protector the tube is placed into a fibre splicing machine and the two glass
ends are fused together to in essence create a single piece of glass tube. Therefore creating a
new continuous fibre core for communication.
Locating breaks in fibre optic cabling
The outline above of repairing fibre cables is all well and good when you know where the
break and damage has been done.
However when you lose connection on one of your links the process of finding that damaged
area can seem impossible
However with a tester called an OTDR these faults can be found very accurately
OTDR - Optical Time Domain Reflectometer
What is the OTDR used for?
The unit is used for not only fault finding but also to test overall fibre link installation
The unit’s main uses are for
1. Measuring the length of the installed fibre cable
2. Calculating the overall loss along the fibre cable
3. Highlighting the loss calculations of each event along the link which is mainly joints
/splices. These also include the ultimate end termination points
4. Fault finding
The unit works on the reflection of lights back along the length of the cable once the light is
launched into the cable from one end. As the light hits certain points of the cable spikes are
showed where the light is reflected. Small reflections shown for natural bends and parts of the
cable. Larger spikes are seen at the start and end of the cable as the light hits the termination
points. Furthermore these spikes will be seen for splice points along the cable.
Each of these spikes is in essence loss of signal along the cable
An in depth study into OTDR testing can be found on the FOA Website
OTDR and locating breaks in fibre optic cabling
The OTDR will measure the distance to a major event and show it on the light trace. When a
cable is broken it shows a certain event on the OTDR trace. The fibre optic cabling installer
can then move the cursor to the event of the broken cable and the unit calculates how far it
from the start of the cable. In addition the test can be done again from the other end and get
another distance to the break.

3. With these two distances it can be accurately estimated where the break in the cable is so it
can be found.
Fiber optic cable repair cost
How much does it cost to repair fibre optic cable?
The cost will depends on many factors but as an outline our professional fibre optic cabling
installers with fusion splicing and OTDR testers are £350-£450.00 per day
The factors that will affect the price to a lower or higher range are as follows
 Type of cable and damaged
The majority of fibre cables are similar in price for a like for like cable. However fibre cables
can range from 4 core cables (4 core connections inside the outer sheath) up to 96 cores and
beyond
When a cable gets broken each core has to be repaired and spliced. Not only do higher core
count cables have more termination repairs they are also harder to handle and therefore more
time consuming
 Location of the damage
The access and environment of the damage will make a difference in cost. Splicing a cable
inside an office will of course be more cost effective than if its external, buried, or required
high access outside of a building. However all are possible and can be communicated upon an
onsite of offsite survey
 Length of the fibre
A longer link will results in greater time to access both ends to firstly test to fault find and
then to test to confirm repair. Fibre cables that are damaged between building naturally take
longer to repairs than repairing a cable inside the same building
Emergency Fibre Repair Call Outs
The majority of fibre optic repairs can be repaired between 2-4 hours once attending the
location. This will depend on factors such as those as above.
About NM CablingSolutions - NetworkCabling Specialist
NMCablingisa technologyandstructuredcablingintegratorworkingthroughoutthe United
Kingdom.
We have createda comprehensive KnowledgeCentre forourindustrywhichcanbe viewed
at https://www.nmcabling.co.uk/knowledge-centre/