Hello everyone!
Today, I will continue to explain underground optical cable installation. In this article, I will explain handholes and manholes. Let’s get started.
Places for storing optical cable reserves, optical closures are called manholes – MH or handholes – HH. Manholes or handholes are made of one or more parts. Once made, drilling and making additional holes is prohibited as this may compromise the stability of the entire structure or lead to damage. These structures have provided holes for the entry/exit of pipes and/or optical cables. Holes that are not used must be closed. Water penetration into manholes and handholes should be prevented.
When it is necessary to work on an existing underground installation:
Provide work in manholes or handholes with appropriate barricades and traffic signs,
It is obligatory for the working team to be at least two people,
The cover is at least 2 m from the entrance to the manholes,
To check whether there are dangerous gases in three levels – bottom, middle and top. Instruments are used to detect and measure hazardous (toxic and/or flammable) gases. Min time for measuring is 60 s for every level,
Once it is established that it is safe to work, one enters the manholes. Use an aluminum ladder to enter the manhole,
Tools and/or instruments are not thrown into the manholes, nor is it carried by a technician who enters the manholes. For these tools and instruments, we have to use a rope or bucket,
Equipment, tools and instruments are prohibited near the edge of a manhole,
During the work in the manhole, constant ventilation is required,
Fusion splicing is prohibited in manholes. Due to the risk of explosion. In the event that there are flammable gases, the electric arc that creates the fusion splicer can ignite the gas,
If there is water, it must be pumped out into the stormwater system.
The permeability and cleanliness of the pipe should be checked and cleaned before installation. For that, special elements are used that connect to the messenger. The tube is then pushed and pulled.
There are situations when the pipes are damaged or impassable. Then you should consult with the project manager, whether to use a redundant pipe or repair the problematic pipe. A repair usually comes down to locating the problem, digging, cutting the pipe, connecting with a pipe connector, and backfilling.
I will continue to explain in the next article>> Underground optical cable installation (5).
Thank you!
