What is bonding
its the connection meant to safely and effectively equalize the potential differences between two metallic items ( ex: equipment rack and cable tray)
What should be verified during the installing of ICT cabling
you should verify that exposed conductors, cable shields, and metal equipment are grounded or free of fault potentials and are otherwise generally safe
what should overall protection protect from
direct lightning strikes, ground potential rise, contact with power circuits, induction, transient voltages
what three interconnected grounding systems must be at every site
the ac electrical power grounding (earthing) electrode system ( also known as the earthing system).
Equipment grounding system or it may be known as the equipment bonding system in countries outside of the us
telecommunications bonding infrastructure
what is an electrical power grounding (earthing) electrode.
its a device that establishes an electrical connection to the earth. its usually a rod, pipe ,or plate that helps make that low impedance connection
What does a PBB serve
The primary bonding busbar serves as a central attaching point for all equipment and other busbars within the building. is the dedicated extension of the buildings earthing electrode system for the telecommunications bonding infrastructure
what is the size of a PBB
its 101.6mm (4in) and has a varying length with different sized holes to accommodate a wide range of conductor and connector sizes
what is the minimum clearance the busbar must have behind it when mounted
50mm or 2in clearance
Where should the PBB be located and be placed
-it should be located in the telecom EF but should be placed to minimize the length of the tbc that bonds the pbb to the buildings earthing electrode system
- it should have an isolated mount to avoid unwanted potentials
- it should be positioned adjacent to the telecom circuit protectors and directly between the telecom circuit protectors and the building ground for protector operation.
What is an SBB and what is the size of it
The secondary bonding busbar is 50mm or 2in wide with a varying length. It is the connection point for telecom systems and equipment in the area served by a telecom space
What clearance should a sbb have after it’s been mounted?
50mm or 2 in
Where should the SBB be bonded to
The equipment ground terminal of the ac electrical panel boards serving telecom equipment in the ER or TR to equalize potentials between them
What is a TBC and what does it do
A telecom bonding conductor bonds the electrical systems electrical power grounding (earthing) electrode system to the PBB
What is a TBB and What does it do
A telecom bonding backbone is a copper conductor with a minimum diameter size of 6 awg that interconnects the PBB to the SBB.
Its intended to equalize potentials between trs on multiple floors of a building with ultimate connection to the PBB
The TBB should be an insulated, stranded copper
What is BBC and what does it do?
A backbone conductor is an insulated, stranded copper conductor, with a minimum diameter size of 6 awg, it’s used to equalize potentials between SBBs on the same floor of a structure.
Standards such as TIA-607 recommended that a bbc be made on every third floor and the top floor of multi story structures
What does the TEBC do?
The telecom equipment bonding conductor connects equipment cabinets and racks to the closet PBB or SBB. A TEBC is typically an insulated, stranded copper conductor with a minimum diameter size of 6awg
What is a supplemental bonding network
A supplemental bonding network is a set of conductors or conductive elements formed into a mesh grid, which becomes part of the bonding infrastructure within an ER or data center.
It’s associated with raised access flooring
Should all bonding connections follow the manufacturer’s installation guidelines?
Yes definitely
When testing grounding and bonding what should the metering measurements be made for
Two point bonding resistance
True root mean square ac current
The dc current
The ac outlet wiring polarity/ conductor impedance
How is the earthing test performed?
What is the recommended maximum value for the bonding resistance between the two points( the bus bar and the er or tr.
By connecting the meter leads between the nearest available electrical power grounding( earthing) electrode and the busbar in the Er or Tr.
0.1 ohms (100miliohms
Name the three types of telecom circuit protectors
Primary protectors , secondary protectors , data and fire alarm protectors
What are primary protectors used for
They are intended for application on exposed circuits, they must be installed as close as possible to where the exposed cables enter the building and the grounding conductor must safely carry lightning and power fault currents.
What are secondary protectors used for?
These may not be required by codes but are typically used for additional protection behind primary Protectors
What are data and fire alarm protectors?
These are the more sensitive Modules with a lower fault threshold because they don’t have to allow for the 90v associated with a telephones ring voltage.
They may not be required by code they just perform primary lighting protection against lighting transients
