Bus bar And Bus bar Chamber

• The incoming supply to bus bar is controlled by switch fuse unit or MCB. 
• The outgoing circuit from bus bar to load point is controlled by switch fuse unit. 
• The bus bar chamber is a heart of switch fuse unit and it is main junction of incoming and outgoing line. 
• The bus bar is made of aluminum or copper strip. 
• There are four bus bar requires for supply system of 3 – Phase, 4 – wire.
• There are 3 strips used for phase connection and one strip for neutral connection. 
• The bus bar strip is mounted on Bakelite, Porcelain or insulating material. 
• The length and width of the bus bar strip depends upon the current passing through strip. 
• The outgoing connection through bus bar chamber is taken through wire or bus bar strip. 
• The joint of bus bar strip is done through other material but in order to avoid corrosion it should be painted. 
• There are two supports requires for 1 meter length of bus bar. 
• The switch board and Distribution board is mounted on wall by using of frames. 

The following things to be noted for bus bar connection. 

• The length of bus bar chamber should be 10 meter more than that of length of bus bar. 
• The distance between two feeders for each bus bar should be at least 5 cm. 
• If the current capacity is 200 Amp then it is 5 cm and for 400 Amp, it should be 10 cm. 
• The minimum distance between end of bus bar and support should be 3 cm. 
• There is only one connection for each hole provided in the bus bar. The connection of round bus bar is through nut bolt and clamp.

BUS BAR CHAMBER

• The supply in the High rise building and complex is given through bus bar chamber. 
• There are 4 copper strips / aluminum strip is used in the bus bar chamber. 
• There is one incoming line and one or more outgoing line is used. 
• The size of the bus bar chamber depends upon following factors.
• The size of bus bar depends upon current capacity of the bus bar. 
• The switch number and rating is given to the bus bar chamber. 
• The bus bar chamber is made of 16 SWG Mild steel sheets. 
• If the current capacity is 400 Amp, the size of the bus bar should be 50 mm * 5 mm copper and 50 mm * 10 mm aluminum.

Distance between Bus bar For Given Voltage

SR. NO	VOLTAGE	CLEARANCE IN MM
		BETWEEN PHASE	BETWEEN PHASE TO EARTH
1	415 V	19	16
2	0.6 kV	25	19
3	3.3 kV	51	35
4	11 kV	127	77
5	22 kV	242	140
6	33 kV	356	223

Dimension of bus bar Chamber, its Size and Number of Strips for Given Current Rating

Number of Epoxy / Porcelain insulator per Phase = 3

Aluminum / Copper bus bar length in ( mm ) = 1000

Dimension of Bus bar Chamber L * H * B ( mm )	Current rating   ( Amp )	Rectangle Cross section
		Copper		Aluminum
		No. of Strips / Phase	Size        ( mm )	No. of Strips / Phase	Size ( mm )
1150 * 400 * 150	100	1	20 * 5	1	25 * 5
1150 * 400 * 150	200	1	30 * 5	1	40 * 5
1150 * 400 * 150	300	1	40 * 5	1	50 * 5
1150 * 500 * 300	400	1	50 * 5	1	50 * 10
1150 * 500 * 150	630	-	-	2	40 * 10
1150 * 500 * 300	800	-	-	2	50 * 10

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