1. Prepare the duct system accordingly:

Prepare the duct system by conducting a leak test to verify tightness, checking the patency and geometry of the duct, and cleaning and lubricating the duct.

2. Select the appropriate cable diameter for the existing duct system:

The diameters of the cable and duct must be compatible. The percentage of fill ratio should be between 30 and 60 percent to ensure that your cable is suitable with the duct. Performances are definitely affected if sizes are below and above the specified limits.

Percentage of occupation = (cable OD)² / (duct ID)²
The easy calculation is: 0.5*(duct ID) < (cable OD) < 0.7*(duct ID)

”cable OD” stands for “Cable Outer Diameter”
“duct ID” stands for “Duct Inner Diameter”

3. Choose the correct compressor for the specific duct and cable size:

For larger ducts with diameters of ¾” - 2 ½” (cable diameter of .35”-1.25”), a compressor with an operating pressure of 8-10 bar (100-175 psi) and a cable speed of up to 60 meters per minute is recommended. For smaller ducts with diameters of .27” - 1.66” (cable diameter of .15” - .60”), a compressor with a pressure of 7-16 bar (100-232 psi) and a cable speed of up to 400 feet per minute is appropriate. Micro ducts with diameters of 0.118” - 0.472” (cable diameter of 0.031” - 0.157”), require compressors with a pressure of 10-12 bar (100-174 psi) and a cable speed of up to 550 feet per minute.

4. Select the proper blowing machine:

For ducts with diameters of 0.75” - 2.48” (cable diameter of .35”-1.25”): Choose the bigger more powerful blowers.

For ducts with diameters of .27” - 1.66” (cable diameter of .15” - .60”): These will be your average blower sizes and more universal to different duct sizes.

For ducts with diameters of 0.118” - 0.472” (cable diameter of 0.031” - 0.157”): These will be the small, micro duct blowers.

5. Select appropriate equipment:

Select the appropriate equipment for the installation, including air coolers, air dryers, and air heaters for compressors, Y connectors and blowing heads for fiber blowing, cable trailers and stands for cable pay-off, and accessories for tubes and micro ducts such as trailers, unwinders, cutters, leak testers, calibrators, and location probes.

6. Proper organization of the construction site:

Ensure proper organization of the construction site, including free cable unwinding, secure and stable placement of the blowing machine, and proper alignment of the cable drum, blowing machine, and duct.

7. Proper education and training:

Provide proper education and training to all personnel operating the machinery and ensure that they are equipped with appropriate protective clothing.

8. Proper preparation of the cable:

Prepare the cable properly by coiling it correctly, checking for deformities or damage, and ensuring that it is clean. Use a suitable cap on the head of the cable.

9. Conduct a CRASH TEST

Conduct a crash test by finding the maximum allowable pushing force. Do this by setting the motors to low power and start the feeder so that the cable hits the end of the blanked conduit at the highest possible speed. Repeat the operation several times, increasing the power of the motors each time, until you make the cable break.

10. Carry out the blowing process correctly

Follow the correct procedure for blowing the cable into the duct, including placing a brass cable protector on the end of the cable, pouring the appropriate amount of lubricant into the duct, manually inserting the cable into the duct, and using compressed air to feed the cable into the duct at an appropriate pressure and speed. If the desired length is not achieved, stop blowing and try again after a few minutes, starting with the minimum pressure on the head. By following these guidelines, the installation of fiber optic cables in a duct system can be accomplished safely and effectively.