Data communications, conduit and trunking types Flashcards
What is a LAN and what is it used for?
A LAN is a local area network, and is installed in an organisation to link computers, servers and printers together.
What Frequency does CAT 3 support?
Cat 3 supports frequency’s upto 16 MHz
What Frequency does CAT 4 support?
CAT 4 supports frequency’s upto 20 MHz
What Frequency does CAT 5 Support?
CAT 5 supports frequency’s upto 100 MHz
What Frequency does CAT 6 and CAT 6(a) support?
CAT 6 supports frequency’s upto 250 MHz and 6(a) supports frequency’s upto 500 MHz
What is the maximum length a CAT 5 cable should be before being put into a a switch or repeater?
A CAT 5 cable should be no longer that 100m. This allows for 90m of cabling two connectors and two five metre patch leads
What is the bend radius of CAT 5 cable
Bend radius should be 4 time the overall diameter of the cable.
What is Fibre optic cable?
Fibre optic cable consists of one or more optical fibres, it then consists of a cladding and coating for total internal reflection.
How is data projected on a fibre optic cable?
A light source is projected in one end and is reflected off the borders between the core and cladding. By switching light source on and off vast quantities of data is transmitted.
What are some advantages of fibre optic transmission?
Very Large data transfer rate
No electromagnetic interference
Longer lengths of run without need for repeaters
Better data security
What are some disadvantages of fibre optic transmission?
High installation cost
Complicated installation procedure
Possible health risk during installation
What are 2 hazards associated with fibre optic cable?
When stripping it is possible a small shard of fibre could enter the blood stream and cause fatal damage
You should never look down a fibre cable as the laser could fire and damage your eyes
Define an auxiliary circuit
is a circuit for transmission of signals intended for control, detection, supervision or measurement of the functional status of a main circuit.
Give an example of an auxiliary circuit
DOL a direct online starter and a heating control circuit
Give an example of different types of wiring environments
Domestic Commercial Hazardous Industrial Agricultural
Give an example of cable which can be ‘Clipped Direct’
MICC - Mineral insulated
SWA - Steel wired armour
XLPE - Cross linked polyethelene
PVC/PVC - Polyvinyl chloride / Polyvinyl chloride
What are some advantages of steel conduit and trunking?
They are strong and able to resist mechanical stress, they can also be used as CPC
Pemit easy wiring
minimise fire risk
Where is plastic conduit and trunking most likely to be used?
Plastic conduit is most likely to be used in commercial premises with single core cables.
What is an advantage and disadvantage of PVC conduit
it is less robust than steel conduit although easier to install. lightweight Simple to form and bend Minimal condensation Electrical and fire resistant
Where would cable tray most likely be used?
Cable tray would be used in situations where individual clipping is difficult or not economical. Typically used above ceilings or industrial settings.
What range of sizes does cable tray come in?
50mm to 1000mm
Where is ladder rack used?
Ladder rack is used in industrial settings, where a large number of sub-main cables must be run
Where is basket tray most likely to be used?
Basket tray is most likely to be used in commercial premises to run data cabling and small power cabling.
What are the 3 main types of tray and conduit?
PVC
Metal
Flexible
List some disadvantages of disadvantage of steel conduit
moisture is likely to form inside steel conduit
expensive to install
Liable to corrosion
List 2x different types of finish for steel conduit
galvanized for outdoors
Black enameled for general work
List Disadvantages of PVC conduit
Care must be taken when gluing joint to avoid forming a barrier inside of conduit
If insufficient adhesive is used joints may not be waterproof
PVC expands 5 times as much as steel
List the 4 different type of PVC conduit
Heavy Gauge Super high impact
Light gauge super high impact
Heavy gauge standard impact
Heavy Gauge high temperature material
What are the 3 main types of trunking
Metal
PVC
Mini trunking
List some advantages of steel trunking
Affords conductors good mechanical protection
Can accommodate many cables of different sizes
Permits easy wiring
Minimise fire risks
Can be utilized as CPC
List some disadvantages of steel trunking
Expensive compared with other systems
requires skill to fabricate and install
difficult to make gas and waterpoof
liable to corrosion
What are the three main types of cable tray
Standard duty cable tray
Heavy duty cable tray
Return flange cable tray
Where is cable ladder used and what is it used for?
Used in industrial settings
used for larger cables
