Sunday, October 9, 2016

Structure Cabling systems

Structure Cabling systems
·         Is the infrastructure work inside building for IP systems such as ( telephone & data over IP, IP public address system, IP CCTV, IP Access control, IPTV, IP CLOCK,..... )
·         Note : Each system will be introduced in a separate post
Codes & standard
·         TIA/EIA 558
·         BICSI Standard
Structure Cabling components:
-          RJ45 outlet
·         An 8-pin/8-position plug or jack is commonly used to connect computers onto Ethernet-based local area networks (LAN). Two wiring schemes–T568A and T568B–are used to terminate the twisted-pair cable onto the connector interface (Wall mounted &  Floor mounted )

-          Cables
·         Fiber optic cable
-          There are two types for fiber cable :
-          Multi-mode
Multi-mode Fiber Patch Cables are a good choice for transmitting data and voice signals over shorter distances. They are typically used for data and audio/visual applications in local-area networks and connections within buildings or remote office in close proximity to one another,
Transmission speed are limited in multi-mode as follow:
100 Mbit/s for distances up to 2 km (100BASE-FX).
1 Gbit/s up to 1000 m.
10 Gbit/s up to 550 m

-          Single mode
Single-mode Fiber Patch Cables are the best choice for transmitting data over long distances. They are usually used for connections over large areas, such as college campuses and remote offices. They have a higher bandwidth than Multi-mode cables to deliver up to twice the throughput.

·         Unsheilded twisted pair cable UTP Cable
is the most common kind of copper in horizontal wiring for all systems based on IP technology , the benefits of twisted pairs is to reduce cross talk or electromagnetic interference between pairs.
-          types of Unsheilded twisted pair cable:
from CAT1 to CAT7
 ( all category will be introduced in a separate post in details)

-          Cable trunk
·         is an enclosure usually with a rectangular cross section, and with one removable or hinged side, that is used to protect cables from dust or water ingress.can be 1 or 2 or 3 compartment.

-          19- inch Rack 
·         is a standardized frame or enclosure for mounting multiple equipment modules. Each module has a front panel that is 19 inches (48.3 cm) wide. The 19-inch dimension includes the edges,
-          Fiber patch panel
·         Used to terminate fiber optic cables and provide access to the cable’s individual fibers for cross connection.

-          UTP patch panel
·      UTP Blank Patch Panel is designed to work with UTP high-density modular connectors. The modular connectors exceed all channel performance requirements in TIA-568-C.2 from 1 MHz to 500MHz to support the IEEE standard for 10 Gigabit Ethernet over UTP premise cable.

Thursday, October 6, 2016

Public Address system

The Public Address system shall be a complete system for amplifying sound signal from
microphones, background music source and distribute them to loud speakers at various
locations with provision to distribute sound on selective and zonal basis as shown on the
riser diagram.
-          Microphones ( wire & wireless )
·         Types:
-          Dynamic microphones
-          Condenser microphones
-          Ribbon microphones

·         Specification
-          Sensitivity
-          impedance

-          Speakers
·         3 types ( wall mounted, surface mounted & recessed mounted )
·         Cover area approximately about 30 meter square and located every 6 meter at corridor.

-          Amplifiers
-          is an active component that increases the output signal of a sound source (e.g. microphone) and passes its output signal to a sound transducer (e.g. loudspeaker).
-          Capacities
( 120w, 240w............)

-          Matrix
§  The main unit for the system which work as the interface between the system inputs as ( microphone, radio & CD player ) and the ouput units as speakers
-          FM\AM radio

-          CD\DVD Player

-          Volume control ( attenuator )
·         Located at closed rooms and it have different wattage capacities depend on number of speaker connected to volume control.

-          Network audio adaptor
·         Used only in IP public address

-          Rack
·         All previous devices will be located inside the rack which will be located in the main control room of the project

-          Types of cable used in public address system
·         Shielded twisted pair cable 2 x 1.5 mm   

-          Types of conduits  used in public address system
·         PVC Conduits
·         EMT Conduits used in Exposed installation when using public address in voice evacuation
·         UPVC Conduits used in outdoor installation

Thursday, September 29, 2016

Fire alarm system-design secrets

Addressable  system design secrets:
·      Distance between Smoke Detector mustn’t exceed 10 m to avoid dead area between detectors
·      Distance between heat Detector mustn’t exceed 7 m to avoid dead area between detectors
·      Fire detector must be mounted at least one meter from any forced air inlet.
·      Ramps at car parking must be covered by heat detectors
·      Voice evacuation located at escape stair must be in a separate loop.
·      Fire fighter telephone must be located at elevator lobbies & pump rooms.
·      Each fire loop must have 20% spare capacity.
·      Access control system ( ACS ), elevator, Door holder,Public address system ( PA ), exhaust fan’s, Air Handling Units( AHU’S ) connected to fire alarm system via control module ( CM )
·      Fire fighting system( FM200, CO2, Sprinkler system( flow switch & Tamper switch ) ) connected to fire alarm system via monitor module ( MM ).
·      Alarm bell located at 2200mm above finished floor level.

Fire alarm system

Codes & standard
·         NFPA ( National Fire Protection Association ) 
·         BS 5839 ( British Standard )
·         VDS ( Germany)
System types:
·         Addressable  system
·         Conventional system
·         Wireless  system
Addressable  System Components:
-          Smoke Detector
·         2 types (optical smoke detector & ionization smoke detector ( not used now) )
·         Located at
§  all rooms, halls, storage areas, basements, attics, elevator, shafts, enclosed stairways, dumbwaiter shafts, and chutes.
§  Cover area with raduis ( r= 5m )  toatal area equal πr square = 80 meter square.
-          Heat detector
·         2 types ( fixed heat detector & rate of rise heat detector)
·         Located at:
§  generator room, Kitchen & Boiler room.
§  Cover area with radius ( r= 4m )  total area equal πr square = 50 meter square.
-          Multi-sensor ( smoke & heat ) detector
·         Locate at: ( electrical, communication, mechanical & control )rooms
-          Flame detector
·         2 types ( Ulta-Violet UV & Infra Red)
·         Locate at:
§  petrol station & workshop nearest to source of flame
-          Beam detector
·         Consists of transmitter  ( T ) and receiver ( R ), Located at wide open plan areas
-          Gas detector
·         Located at Kitchen nearest to source of gas
-          Carbon Monoxide detector
·         Located at place that may be contain co gas as garage area
-          Duct smoke detector
·         Located at HVAC duct at return & supply
-          Manual station
·         Locate at:
§  Entry/Exit doors, at corridors every 61 m at height not less than 1.1 m and not more than 1.37 above floor level as per NFPA requirements
-          Fault Isolator
·         Located very 20 device inside fire loop to make loop continue working in case of any short circuit in the loop
-          Control module
·         Used to control exhaust fan’s,Air Handling Units ( AHU’S),Elevators...............
-          Monitor Module
·         Used to monitor fIre fighting system as ( FM200, CO2..........)
-          Fire  alarm repeater panel ( FARP)
·         Used to show faults as in main fire alarm panel but no action can be taken from FARP, Located at any floor beside counter areas
-          Types of alarms
·         May be  audio / audio with strobe / strobe
-          Alarm devices
·         Bells
·         Horn speaker ( outdoor )
·         Evacuation with Strobe light ( Flasher )
-          Types of cable used in fire alarm systems
·         Fire retardant cable till 105  ͦC 
·         Fire resistance cable [ 750 ͦ ,950 ͦ,1050 ͦC]
·         Fire  alarm cable must be Copper conductor ( retardant or resistance )with cross section
·         2 ( 1pair ) x 1.5 mm( cable cross section )
·         Cable cross section depend on number of device ,detector & loop length  
-          Types of conduits  used in fire alarm systems
·         PVC Conduits used in embedded installation 
·         EMT Conduits used in Exposed installation
·         UPVC Conduits used in outdoor installation

Fire Alarm Control Panel ( FACP ), Workstation & batteries

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