UNIT TEST 1 PSP

ROLE OF POWER SYSTEM PROTECTION

• To safeguard the entire system to ensure continuity of supply.

• To minimize damage and repair costs.

• To prevent undue thermal and magnetic overstressing of healthy equipment on through fault.

• To ensure the safety of personnel.

• To keep voltage depressions as short as possible in the interests of plant stability.

Types of Faults

• Open Circuit Faults

• Short Circuit Faults

• Symmetrical Faults

• Unsymmetrical Faults

protection

Types of Coordination

• Selective Coordination

• Interrupted Coordination

• Protection Coordination

A single line diagram, where provided for the electrical system, shall be maintained in a legible condition and shall be kept current

• NFPA 71E 2015 (Article 205.2)

• NFPA 70E 2015 (Article 205.2)

• NFPA 75E 2015 (Article 205.2)

• NFPA 75E 2015 (Article 205.2)

Types of ELectrical Diagram

WHAT CAUSES ARC FLASH?

• Equipment failure.

• Dropping un-insulated tools or metal parts.

• Using incorrectly specified instruments.

• Live work on damaged equipment such as cables.

• Loose connections and exposed live parts.

  Lack of awareness and training.

protection draw and label

Passive Fault Types

Types of Induction relay

• Shaded pole

• Squirrel Cage

• Wattmeter or double pole winding structure

• Induction cup structure

• Drum-Type