192 Topic 5

Slide 1: Topic 5: Earthing and surge suppression concepts

Slide 2: Topic 5: Earthing and surge suppression concepts •Protect people against injury •Provide a reference point for voltage and signal measurement •Assist anti-surge devices to protect equipment from high voltages on the line •minimise some types of electrical interference •transmit control signals between equipment

Slide 3: Topic 5: Earthing and surge suppression concepts Fig 1: Earth Leakage Circuit Breaker

Slide 4: Topic 5: Earthing and surge suppression concepts Fig 2: Earthed star point in a three phase electrical system

Slide 5: Topic 5: Earthing and surge suppression concepts Fig 3: MEN

Slide 6: Topic 5: Earthing and surge suppression concepts Fig 4: Equipotential Bonding

Slide 7: Topic 5: Earthing and surge suppression concepts Fig 5: Telecommunications Earthing

Slide 8: Topic 5: Earthing and surge suppression concepts TRC CES Telecommunications Communications Reference Earthing Conductor System Fig 6: TRC and CES

Slide 9: Topic 5: Earthing and surge suppression concepts A TRC distribution system may consist of the following: •TFEE where required •TFE conductor, estending the earth from the TFEE to the earth bar at the CD/BD •TRC conductors extending from the CD/BD earth bar direct to a CSS or CE, or to FD earth bars and subsequent Fig 7: Telecommunications reference conductor (TRC)

Slide 10: Topic 5: Earthing and surge suppression concepts Refer to Technical Standard TS 009 Figures 1 to 4 for details on the connection of TRC Fig 8: Bonding via a differential earth clamp

Slide 11: Topic 5: Earthing and surge suppression concepts CES = TRC + PE Refer to:Technical Standard TS 009 Figures 1 to 4 for details on the connection of CES Fig 9: Communications Earth Systems -earthing wires

Slide 12: Topic 5: Earthing and surge suppression concepts Fig 10: Surge Suppression- causes of surges

Slide 13: Topic 5: Earthing and surge suppression concepts Fig 11: Surge Suppression- surge protection 1. Interception of the lightning strike

Slide 14: Topic 5: Earthing and surge suppression concepts Fig 13: Typical surge suppressors