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Types of Switch gears: •LT switch gear•H.T switch gear

The basic function of L.T and H.T switch gear are:•Electrical protection•Isolation•Over voltage protection•Under voltage protection•Over current protection

SWITCH GEAR

Electrical devices used for metering, protection and control of an electrical system are defined as switch. The safe operation of the system requires the switching to open lines automatically in case of a fault, or manually when the operation requires it.

L.T Switch Gear:L.T stands for low tension. These panels work on 415v.

Current Transformers

C.B1

C.B2

C.B3

C.B4

C.B5

Three Phase Meter Block Diagram

M N N

L MLM L

Fuses

Circuit Breaker

T

Low voltage gear consist of following panels:•L.T switch board•Distribution board•Relay panel•Control panel•PFI(Power factor improvement) panel

Current Transformers

C.B1

C.B2

C.B3

C.B4

C.B5

Three Phase Meter Block Diagram

M N N

L MLM L

Fuses

Circuit Breaker

T

H.T Switch Gear: H.T stands for high tension. These panels are placed in factories and in substations.

H.T switch gear consist of following panels:•Incoming panel•Outgoing panel•Bus coupler•Industrial panel•Consumer panel•Owner panel

Vacuum Circuit breaker: VCB is an important device used with H.T panels to provide protection to the system.

VCB consists of:•Vacuum interrupter•Upper and lower pole support•Flexible terminal•Upper and lower insulator•Insulator coupler•Contact pressure spring•Cross arm•Centering ring

Tests that are performed on Switch gear are:•Short circuit test•Power frequency test (In main circuit 36KV for 1 minute)•Test on auxiliary(to test the electrical device installed)•Dielectric test(Control winding 2KV for 1 minute)•Measurement resistance test of main circuit•Rack in rack out•Interlocking