Dear All,

Substations shall be provided with a full interlocking scheme to ensure that all disconnectors, fixed earthing switches (or other interlocked earthing devices) and, where required, circuit-breakers are operated in the correct sequence so that personnel do not endanger themselves and/or the integrity of the transmission system by incorrect or inadvertent operation of equipment. Where necessary, such interlocking shall also be extended to cover limitation of access to areas where there is a risk that normal safety clearances may be infringed. Interlocking is one of the most important topic for operational engineers. Therefore realizing the requirement, I have prepare the training about substation operational philosophy and interlocking.

In this training following topics are covered.

· Explained Isolator and earth switch functionality

· Difference between high speed earth switch and normal earth switch

· Open, close and intermediate position of switchgear equipment

· Symbols & components of Single line diagram

· Different types of busbar schemes

o Single bus Single breaker scheme

o Double bus single breaker scheme

o Double bus double breaker scheme

o One and half breaker scheme

o Ring busbar scheme

· Operational philosophy and interlock logic

· Electrical and mechanical interlock

· Interlock by pass command

· Line Bay Interlocks

· Transformer Bay Interlocks

· PT Bay Interlocks

· SOP for Line Isolation & Restoration explained

· SOP for Transformer Bay Isolation & Restoration (Copy attached )

· SOP for Line Trip & Restoration explained

· SOP for Transformer Trip & Restoration (Copy attached )

Best Regards