Main Switch Board (MSB)
MSB Cabinet is made of Steel (Sheet)
Cabinet is divided into many sections/compartments
Electrical Power from the Generators is collected in the MSB through Generator Switch Board/Panel
From the MSB, Electrical Power is distributed to various Utilisation Devices through Group Feeder Panels / Group Starter Panel
440 V Devices are supplied from 440 V Bus Bars (440 V Feeder Panels / Group Starter Panel)
440 V is step down to 220 V using a Step Down Transformer
220 V Devices are supplied from 220 V Bus Bars (220 V Feeder Panel/Section)
Shore Supply (during Dry Dock) is connected to MSB
MSB Supply the power to Emergency Switch Board (When Main Generators are running)
Front door & back doors are hinged to facilitate operation, inspection &cleaning
Operating handles and push buttons of the devices are mounted on the front doors/panels
MSB is arranged symmetrically
Generator Switch Board /Panels in the Middle
Feeder Panels/Group Starter Panels distributed equally on either side of the GSB
Devices / Instruments / Components fitted in MSB
Switch Gears/Circuit Breakers
440 V Main Bus Bars ( 3 no’s)
220 V Bus Bars ( 3 no’s)
Bus-Tie
Monitoring & Controlling Systems / Devices
Measuring & Indicating Instruments
Ammeters
Voltmeters
Frequency meters
Watt meters
Synchronising Unit (Synchronoscope)
Power Factor meter
Insulation Resistance meter
Step Down Transformers
Safety provided in MSB
1.Circuit Breakers (With Arc chute)
2.Short Circuit Trip
3.Overload Trip
4.Low Frequency Trip
5.Under Voltage Trip
6.Phase Imbalance Trip
7.Reverse Power Trip
8.Preferential Trip
9.Over Speed Trip
10.Fuses
11.Earth Fault Indicators
12.Panel Doors are Earthed
13.Ebonite Rod
14.Rubber Mat in front and back of MSB
15.Dead Front Type
16.0.6 metre gap between MSB & bulkhead
17.No Water or Steam or Oil pipeline to pass in the vicinity